# My project: Adding batteries to my 2014 Toyota RAV4 EV



## Jimbo69ny (Feb 13, 2018)

So I have been toying with this idea for a while. I really dove into it this week, researching specs, costs, and battery options.

*Goal:*
I'd like the largest battery possible but I only want to sacrifice the lower storage space in the rear cargo area.

*Time frame:*
Because of the cost involved, I probably wont be able to do it in the next 6 months. There are a few cheaper things I can purchase to get started but the batteries are going to be expensive so those will have to wait at least 6 months. It would be nice if I could get it done in time for NDEW this September.

*Battery Options:*
Battery voltage of additional pack would need to be as close to 386 volts as possible for any pack I add. I read a post from Valerun in which he said his target voltage is between 382 and 386. If you haven't seen the set up that he built you can find it here, 
http://www.myrav4ev.com/forum/viewtopic.php?p=12189#p12189
I plan on using 18650 cells, the same that Tesla used, so I am simply going to match their 92 cells in series in order to match their voltage. If I was going to use a different chemistry, my voltage target would be 382 - 386.

Option 1. Tesla modules from a Model S, X or even a Rav4 EV.
Pros: Prebuilt, high quality, includes liquid cooling system
Cons: Heavy, large, expensive
I would need 16 - 24volt Tesla Model S modules in series just to get to the voltage I need. That would take up the entire lower cargo area and I would have to build up the floor to fit more, losing most of my cargo space. I dont want to do that. I can fit 5 in the lower cargo area but that wouldn't give me the voltage I need to put it in parallel with the main pack. If I am missing something here let me know.
Here are modules for sale for $1400 each.
https://www.ebay.com/itm/Tesla-Mode...881194?hash=item3d139a406a:g:q2UAAOSwPcVVv8qO

Option 2. Build my own modules using 18650 cells
Pros: Customizable to any shape and configuration I need, I can build a higher kwh pack that is smaller, cheaper than Tesla modules.
Cons: Lots of labor to build, no onboard cooling system (They would have to be air cooled).
Cost is about $1.50 per cell if it is 2600mah up to $4.50 per cell if it is 3400mah
I would build one like this. https://youtu.be/JQa5gn-7D74

There are other options but these are the two I have been looking at. I am leaning strongly towards option 2.

*Battery Plans (option 2):*
Option 2 seems like the best option although it would be more work. It is a huge investment so I am open to ideas if you think there is something better out there.
I can fit 9 modules in a vertical formation in the lower cargo area. I can fit up to 314 cells in each module plus more the sides of the box. I am planning on a 92s31p configuration. In order to get there I'll have 310 cells per module, 10 total cell blocks in each module plus 2 rows of 31 cells in parallel on the sides of the box. That's 2,852 total cells in this configuration. 

Vertical modules allowed me to fit more compared to horizontal modules. Also, I think servicing and air flow would be better with vertical modules. 

*Capacity: *
Assuming 92s31p = 
If each cell is 2600 mah, that would be 80,600 mah or 80.6 AH (2600 x 31)
386 volts x 80.6 AH = 31,111.6 WH aka *31.11 kwh* battery capacity 

If each cell is 3400 mah, that would be 105,400 mah or 122.4 AH (3400 x 31)
386 volts x 105.4 AH = 40,684.4 WH aka *40.684 kwh* battery capacity

*Range:*
Weight of car / 10 = watt hours per mile
Rav = 4500lbs
4500lbs / 10 = 450 wh per mile
31,111.6 / 450 wh per mile = 69.14 miles with 2600 mah cells
40,684.4 / 450 wh per mile = 90.41 miles with 3400 mah cells

OEM rating would be:
41,900 / 450 wh per mile = 93.111 miles with OEM 2600 mah cells
41,900 / *350 wh per mile* = 119.714 miles with OEM 2600 mah cells **more realistic**

Theoretical realistic range with additional pack:
31,111.6 / *350 wh per mile* = *88.89 miles* with 2600 mah cells
40,684.4 / *350 wh per mile* = *116.24 miles* with 3400 mah cells
(not including any unusable space in the secondary pack)

Plus existing range from 41 kwh OEM pack! This could possibly be a 230 + mile car!


BATTERY UPDATE:
I have decided on a 92s31p battery pack. I have room for 9 modules in the box I created.

















*Battery Box:*
I'll hire a welder to build me an aluminum battery box that fits inside of the rear lower cargo area. I have built a wood version of the box for the welder to copy. I am going to look into some kind of fire extinguisher system too. Not sure if its possible but I want to protect my family. 

















*Weight:*
Batteries:
92s31p = 2,852 cells
2,852 x 45 grams = 128,340 grams aka 282.94 lbs
Box:
100 lbs ish?
Wiring and other components:
200 lbs ish?
628 lbs total?

*Cost:*
92s31p = 2,852cells
2600 mah $2 x 2,852= $5,704
3400 mah $4.50 x 2,852= $12,834
That's just for the cells 

*Parts Purchased To Date:*
Contactors $61
https://www.ebay.com/itm/Tyco-TE-Re...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
Inertia Switch off ebay $13
20 Dead 18650 cells off ebay $13
400v 300 amp fuse off ebay $15
(2) Panaflow high speed fan NMB120mm FBA12G12H $20
https://www.ebay.com/itm/NMB120mm-F...396a6f96c:g:s~sAAOSwjyhaTFZI&autorefresh=true
Temperature fan control module $2
https://www.ebay.com/itm/W1209-12V-...var=413176014560&_trksid=p2057872.m2749.l2649
Gigavac Hbd41AA $49
http://www.gigavac.com/shop?title_op==&title=hbd41aa1
M22x 1.5 cable glands 5 pack for $8.85
https://www.amazon.com/gp/product/B071VT8NLM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

*Price per kwh:*
Only for the cells. No box or system parts.
2600 mah - $5,704 / 31.11 kwh = $183.34 per kwh
3400 mah - $12,834 / 40.684 kwh = $315.46 per kwh

*Connections:*
I've read that connecting right at the battery is best. Val connected his pack directly to the inverter. However I have Jdemo and Tony has 2 gauge wires going from the battery to a conactor box under the hood. There isn't room to connect additional cable directly to the battery. So I am going to make my connection at the Jdemo Contactor box under the hood. I am going to run high amperage, 2 gauge, shielded EV cable. Its capable of up to 255 amps. Here is a link to the wire specs. http://evwest.com/support/Shielded_Battery-Irradiated_XLE.pdf The existing pack has a 325 amp fuse. But based on my math, and talking to Val, 2 gauge should be fine.

*BMS/System monitoring:*
I haven't explored this yet so I dont know what options are out there. I would like a unit with a display that shows voltage, temp, amp hours, etc of the batteries. Possibly a Batrium unit, https://www.batrium.com/

*Links/Info:*
Inside a Tesla Model S battery pack
https://teslamotorsclub.com/tmc/threads/pics-info-inside-the-battery-pack.34934/
Tesla Battery Specs
http://evwest.com/support/Tesla Model S Batt.PDF
Photos and info on Rav4 EV battery pack
http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=765
http://www.myrav4ev.com/forum/viewtopic.php?f=7&t=2061
http://99mpg.com/blog/somanybatteriessolittletime/
Cut away of Rav4 EV
https://www.youtube.com/watch?v=4XstWdvDWsc
Tear down of Rav4 EV battery
https://www.youtube.com/watch?v=7ZLst_4N4Sw

*My Photos:*
http://s59.photobucket.com/user/jimbo69ny/library/Rav4 EV Additional Battery

*If any of my math, stats or theories are wrong please dont hesitate to correct me. I'd rather know NOW than AFTER I spend $10,000!*


----------



## Jimbo69ny (Feb 13, 2018)

If anyone has any input or suggestions I’m all ears. 

Right now I am researching the effect of having two different capacity batteries. Seems as though the new one will have lower resistance and be the primary battery for the cars needs. Then when voltage drops the OEM pack will transfer voltage to the new pack. Is there anything wrong with that if that is actually the case? Do I need a battery isolator? I haven’t looked at them at all. Are there isolators available that can handle 325 amps and 386 volts?


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> *Battery Options:*
> ...
> I plan on using 18650 cells, the same that Tesla used, so I am simply going to match their 92 cells in series in order to match their voltage.
> ...
> ...


There's also one generation of the Smart ED, but the Smart modules seem like a really awkward size to put anywhere else... and they are 15s. Six of them would be needed to get close (90s), and no number would match 92 (or 96).

My understanding is that all Model S/X modules are 6s, with varying numbers of cells in parallel to suit capacity. Either 14 modules (e.g. 60 kWh variants) or 16 modules (e.g. 85+ kWh variants) are used in series, again to suit capacity (the extra two are in that taller lump at the front). The recent ones all seem to be 16... but that's 16x6 = *96* cells in series, not 92.

It seems popular to fixate on voltages being multiples of 12. The nominal voltage of 6 of these lithium cells in series is not 24 volts (4 volts per cell), but a bit lower. Perhaps your "target voltage" is the maximum reached during charging, rather than the nominal voltage?

Some people have reconfigured these Tesla modules with some cutting and adding of jumpers to make them 12s; with that approach only eight would be needed for 96s... but it looks like that's still too many.


----------



## Jimbo69ny (Feb 13, 2018)

Thank you for the input but any currently available OEM pack would take up more space than I am willing to give up. A custom made 18650 pack in the lower cargo area is the ticket.

I use my car for work and I cant lose any space inside the car.


----------



## brian_ (Feb 7, 2017)

A 92s31p battery (2852 cells) in 9 modules is an interesting configuration challenge. It would be really nice if all nine modules were identical and connected in series - it would be easier to plan, and easier to wire without errors. Unfortunately 92 isn't evenly divisible by 9.

The layout has a notation of "362 cells", but that would be for the full 24 x 14 rectangle; as shown it has 314 cells. Nine of those modules would be 2826 cells... not quite enough for the 92s31p total.


----------



## Jimbo69ny (Feb 13, 2018)

Yeah the series parallel configuration is going to take a close look. I am working on figuring that out now. I think I have it but here is my thread about that. 

https://endless-sphere.com/forums/viewtopic.php?f=14&t=92814&p=1357720#p1357720

It’s really not very clear but I think option 3 is the way to go. That option includes the most connections. 

I am going to have 9 modules with 10 series blocks in each plus 2 more blocks on the right side of the box.


----------



## GreenTecAuto (Jun 14, 2017)

Where are you located?
Interesting project.
I see you linked a few of my things.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> I am going to look into some kind of fire extinguisher system too. Not sure if its possible but I want to protect my family.


You should plan for a fire and understand that a fire extinguisher will not work. What I'd suggest is that you copy the Tesla battery system and include both the pressure valves and fire management ducting to buy your family as much time as possible.

Chris Hazell has produced 3D models of the pressure valves (here)


----------



## Jimbo69ny (Feb 13, 2018)

GreenTecAuto said:


> Where are you located?
> Interesting project.
> I see you linked a few of my things.


Hey Green Tec! Yeah I loved your Rav 4 battery dissection video. Is it possible to let me know if you receive another Rav 4 battery? If its working I might be interested in buying it.


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> You should plan for a fire and understand that a fire extinguisher will not work. What I'd suggest is that you copy the Tesla battery system and include both the pressure valves and fire management ducting to buy your family as much time as possible.
> 
> Chris Hazell has produced 3D models of the pressure valves (here)


Nothing is ever perfect, not even tesla. Of course safety is of the utmost importance. My plans currently are as follows.
1. I have a strengthened and fireproof aluminum box to protect the pack in an accident.
2. I have a trailer hitch that wraps around the lower cargo area for reinforcement. (Where the battery is)
3. Possibly adding a rear heavy duty bumper bar.
4. I want to incorporate some kind of fire suppression system. A fire extinguishing system that senses fire and sprays an ABC fire extinguisher right into the box.
5. I will have a temp/fire sensor that turns off the cooling fans if a fire breaks out.
6. Also, the sensor will switch an actuator that will move a piece of metal that covers the entrance and exit for air circulation. Goal is to suffocate the fire.
7. The same sensor will disengage the contactors.
8. A smoke detector inside of the box. Hearing the beeping will be my first clue to pull over and get the family out.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> 1. I have a strengthened and fireproof aluminum box to protect the pack in an accident.


It's worth reviewing Tesla's approach for separating the battery cells from the cars occupants;

1mm mica sheet

2mm (iirc) steel sheet (top of battery box)

10mm fire blanket

4mm (iirc) aluminium sheet (floor of car)

4mm (iirc) fire resistant carpeting

They also put a lot of effort into managing the gases produced in a fire and exhausting them away from the cars occupants.




Jimbo69ny said:


> 4. I want to incorporate some kind of fire suppression system. A fire extinguishing system that senses fire and sprays an ABC fire extinguisher right into the box.


That will not help in a lithium-ion battery fire. If you're in any doubt watch this and read the first responders instructions...









Jimbo69ny said:


> Nothing is ever perfect, not even tesla. Of course safety is of the utmost importance.


I agree that nothing is ever perfect but I think we can all learn a lot from the monies Tesla have spent bringing EV's to market using 18650 cells.

Two further comments;

afaik you have no battery cooling system in your design 

afaik you have no way of exhausting the gases that are produced when you have a fire. By definition isn't this a bomb?


----------



## Jimbo69ny (Feb 13, 2018)

I have already purchased two high CFM fans. They are on their way. 
https://www.ebay.com/itm/NMB120mm-F...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I also tried this but it was too loud for my wife's liking. 
https://youtu.be/tHBNalKaFwA
https://youtu.be/ZpX2VcjZqkU

If there is a fire I said I want to have actuators that close the intake and exhaust. That should help suffocate the fire and give us enough time to get out.

I appreciate the input. You can pick apart my design and ideas all you want. The whole project is a risk, driving a car is a risk, leaving your house is a risk. I think I am doing a pretty good job taking all things into consideration. The fireproof carpet and mat are a good idea. Ill include that too.


----------



## Jimbo69ny (Feb 13, 2018)

Oh I have an inertia switch. That will trigger everything to close and shut down too.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> If there is a fire I said I want to have actuators that close the intake and exhaust. That should help suffocate the fire and give us enough time to get out.


Lithium battery fires do not require fuel or oxidiser from an external source and sealing the battery box will simply turn the battery into an explosive device, that's why Tesla includes pressure release valves.



Jimbo69ny said:


> The whole project is a risk, driving a car is a risk, leaving your house is a risk.


I'm trying to help you understand so that the risks you take are known as far as possible.

Here's a good example of what happens when a battery 'expert' gets thing wrong (like we all do);


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> Lithium battery fires do not require fuel or oxidiser from an external source and sealing the battery box will simply turn the battery into an explosive device, that's why Tesla includes pressure release valves.
> 
> I'm trying to help you understand so that the risks you take are known as far as possible.
> 
> Here's a good example of what happens when a battery 'expert' gets thing wrong (like we all do);



What is your goal here? To scare me? If you are concerned about my well being give me solutions and not scare tactics. Fear doesnt drive me.


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> I think I have it but here is my thread about that.
> 
> https://endless-sphere.com/forums/viewtopic.php?f=14&t=92814&p=1357720#p1357720
> ...
> I am going to have 9 modules with 10 series blocks in each plus 2 more blocks on the right side of the box.


That makes more sense.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> What is your goal here?


I'm trying to support your stated goal;



Jimbo69ny said:


> I want to protect my family.





Jimbo69ny said:


> If you are concerned about my well being give me solutions and not scare tactics.


If you read my posts you'll find them full of advice based on experience from within the DIY community. Obviously you are free to ignore that advice if you wish


----------



## Jimbo69ny (Feb 13, 2018)

Ok will it seemed like your posts were aimed more at scaring me away from doing it rather than helping me.

Ill accept the fact that you say your just trying to help and move on.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> Ok will it seemed like your posts were aimed more at scaring me away from doing it rather than helping me.


My approach is simple, I imagine that one of my children is stuck inside my electric conversion when a battery fire starts. I don't do this to scare myself rather to ensure I produce the safest design possible based on the available data.

I recommend you read the Tesla battery patents and watch the various disassembly videos that are online. It's clear that Tesla went to a great deal of trouble and expense to use 18650's in cars.

One final thought, if you have access to a Tesla Roadster put your hand over the radiator vents after a 'moderate' drive... I've always found it astonishing how much heat the battery is producing


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> My approach is simple, I imagine that one of my children is stuck inside my electric conversion when a battery fire starts. I don't do this to scare myself rather to ensure I produce the safest design possible based on the available data.
> 
> I recommend you read the Tesla battery patents and watch the various disassembly videos that are online. It's clear that Tesla went to a great deal of trouble and expense to use 18650's in cars.
> 
> One final thought, if you have access to a Tesla Roadster put your hand over the radiator vents after a 'moderate' drive... I've always found it astonishing how much heat the battery is producing


Yup, this is why I dont think I will need a battery heater. I have a timer to charge my car in the morning. Charging warms them up, then of course driving does too. 

I have 2 - 104 CFM fans and time will tell if that is enough to cool the pack. I can always add another one if I need to.

I definitely want to be safe and I appreciate comments that help that goal. I just felt like you were trying to tell me not to do it. I am so sick of people being negative on my posts. Every day people tell me not to do it, I CANT do it, its stupid and its dangerous. It can be done, it can be done safely and it will work.


----------



## GreenTecAuto (Jun 14, 2017)

Glad you like our videos. 
It is rare to come across those batteries, not that many made.

Kevin isnt trying to scare you, just make sure you are full aware of the dangers.
I agree with him, this isnt a project you want to do if you are a learner, because even experienced EV enthusiasts make mistakes.
Im surprised no one posted this yet. A little bit more relivant than just fires.
https://www.torquenews.com/3618/warning-not-to-try-tamper-nissan-leaf-battery-pack

If you are open to other battery types, I have many different types.
Interestingly enough, a you would need all but 2 modules from a Leaf battery to get 92 cells in series. There is also the Fiat 500e, you would use all of that except one module of 5 cells.
Ive noticed that most of the people on these forums are in love with 18650s. My biggest problem with them is the assembly, but that is also one of their advantages. 
What is the size of your box?


----------



## brian_ (Feb 7, 2017)

GreenTecAuto said:


> Interestingly enough, a you would need all but 2 modules from a Leaf battery to get 92 cells in series. There is also the Fiat 500e, you would use all of that except one module of 5 cells.


96 cells in series (and whatever number in parallel is required to reach the desired capacity with the chosen cells), with all modules in series, seems to have become almost the universal configuration for production EVs. In this case there would be an advantage to a production battery which is split into small modules, so that the slightly-lower-than-typical series count can be hit without breaking up modules.

Two common production EV/hybrid batteries jump to mind given that background:

Nissan Leaf - 2s(2p) modules, so could use 46 of the 48 modules
Chevrolet Volt - modules of at least 6s, but can be broken down and reconfigured with (reportedly) reasonable effort to any number in series
Unfortunately, these are both built of relatively large rectangular pouch cells, so the dimensions typically won't pack well into available spaces not designed for them, and the required number in series will a large (in capacity and bulk) battery.

Tesla doesn't make this list because the modules are 6s.


----------



## brian_ (Feb 7, 2017)

GreenTecAuto said:


> Ive noticed that most of the people on these forums are in love with 18650s. My biggest problem with them is the assembly, but that is also one of their advantages.


I agree, but I would say more specifically that

the small size is the advantage for building to suit available dimensions and shape, and
the lack of convenient terminals combined with the high cell count inherent in using small cells are major disadvantages.

There was a format for a while that I thought would be flexible and convenient: cylindrical, larger than an 18650 (so that there were not so many connections), smaller than the big prismatics and pouches, and with threaded end terminals to avoid welding to cells. These were apparently around 40 mm in diameter and at least 10 Ah capacity; Headway still lists some. With the threaded terminals, cells can be combined by just drilling holes in bus plates (like the plates in a Tesla Model S/X module) lined up with the desired cell positions and running machine screws through them into the terminals.

Unfortunately, these larger cylindricals seem to have mostly disappeared, and some had quality problems - I notice that Duncan started with Headway cells in his "Dubious Device" and later switched to a reconfigured Volt battery after problems with the Headways. There are some still available, but I note that one that found (Headway 38120S 10Ah 10C LiFePO4 Cylindrical Battery Cell with Screw) is a LiFePO4... likely not what people want for an EV now.


----------



## Jimbo69ny (Feb 13, 2018)

brian_ said:


> I agree, but I would say more specifically that
> 
> the small size is the advantage for building to suit available dimensions and shape, and
> the lack of convenient terminals combined with the high cell count inherent in using small cells are major disadvantages.
> ...


Yes, there are many advantages of going with a prebuilt pack. However I would direct you back to the second sentence in my original post.....

"*Goal:*
I'd like the largest battery possible but I only want to sacrifice the lower storage space in the rear cargo area."


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> Yes, there are many advantages of going with a prebuilt pack. However I would direct you back to the second sentence in my original post.....
> 
> "*Goal:*
> I'd like the largest battery possible but I only want to sacrifice the lower storage space in the rear cargo area."


I didn't miss that; it's why I said


brian_ said:


> Unfortunately, these are both built of relatively large rectangular pouch cells, so the dimensions typically won't pack well into available spaces not designed for them, and the required number in series will [result in] a large (in capacity and bulk) battery.


Keep your mind open to alternatives, and maybe you'll find a production EV with modules of a size that would work in your specific space, without welding three thousand little cells together by hand.


----------



## Jimbo69ny (Feb 13, 2018)

GreenTecAuto said:


> What is the size of your box?


Its roughly 34" wide by 19" deep by 12" tall.

I realize that the Fortwo tesla cells are close to that but I would have to do some cutting and welding to my floor pan to get those to fit and I dont really want to do that. Plus they arent a perfect voltage match.

I am so glad you guys posted that Rav 4 battery dissection video. That really helped me a lot. 

Did you sell all of those components?


----------



## GreenTecAuto (Jun 14, 2017)

Jimbo69ny said:


> I am so glad you guys posted that Rav 4 battery dissection video. That really helped me a lot.
> 
> Did you sell all of those components?


Ive sold the modules that were good, even the ones that had good and bad blocks.
Someone local came by and bought them for about $1 each good cell.
They are the biggest pain in the ass to take apart, so ive decided not to do it anymore.
I still have all the internal components minus some of the the slave BMS, which really isnt much. Busbars, fuse and fuse holder, contractors, master bms. 
Is there anything in particular you are looking for?


----------



## Jimbo69ny (Feb 13, 2018)

GreenTecAuto said:


> Ive sold the modules that were good, even the ones that had good and bad blocks.
> Someone local came by and bought them for about $1 each good cell.
> They are the biggest pain in the ass to take apart, so ive decided not to do it anymore.
> I still have all the internal components minus some of the the slave BMS, which really isnt much. Busbars, fuse and fuse holder, contractors, master bms.
> Is there anything in particular you are looking for?


Yeah Tesla modules look really difficult to disassemble! Out of curiosity, do you have Smart modules for sale? They do seem like a good option for the DIY person.

I just ordered contactors a couple days ago, I would've said those but I am all set now. I also just ordered fuses. What is the OEM battery fuse anyway? Its winter here in NY and I dont have a garage. I read that it was 325 amps but I havent been able to go out and look. (I'm not a fan of cold weather)

I mainly asked about the parts because I want to try to find out which wires in the harness go to the contactors. There are ways around it but I would really like to be able to tap the signal for the OEM contactors and send it to my contactors. That way my second pack connects at the same time as the OEM pack contactors close. If there was any way you could help me figure that out I would REALLY appreciate it!!!


----------



## GreenTecAuto (Jun 14, 2017)

Jimbo69ny said:


> Its roughly 34" wide by 19" deep by 12" tall.


That might fit 2 of the big stacks from a leaf. 
The stack itself is 35" long, 13 inches tall, and 9 inches wide. That is with the terminals sticking upwards.
Each stack is 24 modules. If you remove one module from each stack, it will give you the appropriate cell count of 92, as well as shorten the length to about 33.5 inches.
The only remaining size problem would be the height. Would you care to go up one more inch?


----------



## Jimbo69ny (Feb 13, 2018)

GreenTecAuto said:


> That might fit 2 of the big stacks from a leaf.
> The stack itself is 35" long, 13 inches tall, and 9 inches wide. That is with the terminals sticking upwards.
> Each stack is 24 modules. If you remove one module from each stack, it will give you the appropriate cell count of 92, as well as shorten the length to about 33.5 inches.
> The only remaining size problem would be the height. Would you care to go up one more inch?


No I dont mind losing an inch or two vertically. I didnt think this was possible, what would I be looking at for kwh? Do you sell these modules? How much? Power curve might be a little different than my OEM 18650s though.


----------



## GreenTecAuto (Jun 14, 2017)

Jimbo69ny said:


> Yeah Tesla modules look really difficult to disassemble! Out of curiosity, do you have Smart modules for sale? They do seem like a good option for the DIY person.
> 
> I just ordered contactors a couple days ago, I would've said those but I am all set now. I also just ordered fuses. What is the OEM battery fuse anyway? Its winter here in NY and I dont have a garage. I read that it was 325 amps but I havent been able to go out and look. (I'm not a fan of cold weather)
> 
> I mainly asked about the parts because I want to try to find out which wires in the harness go to the contactors. There are ways around it but I would really like to be able to tap the signal for the OEM contactors and send it to my contactors. That way my second pack connects at the same time as the OEM pack contactors close. If there was any way you could help me figure that out I would REALLY appreciate it!!!


They are getting harder to come by as well. I had about 60 packs 2 years ago. They all sold through ebay. Came across another 12 about 6 months ago. Already gone.
Ill have to find the box with all the Rav4 tesla components. I have it... somewhere. 
Leaf cells are not thermally managed. so there will be no cooling you can do other than blowing over them with a fan. Im not sure how warm they will get.
Since they are used, i do a capacity check on them. The highest gen1 modules i currently have are 52Ah. I have 2 other packs i have not tested yet.
I also just got a gen 2 pack in that i havent been able to test yet.
The amount you need, and by the time you factor shipping, you are better off sourcing one locally. I have the components for you to make a second stack. That would be the only thing you would need.


----------



## Jimbo69ny (Feb 13, 2018)

GreenTecAuto said:


> They are getting harder to come by as well. I had about 60 packs 2 years ago. They all sold through ebay. Came across another 12 about 6 months ago. Already gone.
> Ill have to find the box with all the Rav4 tesla components. I have it... somewhere.
> Leaf cells are not thermally managed. so there will be no cooling you can do other than blowing over them with a fan. Im not sure how warm they will get.
> Since they are used, i do a capacity check on them. The highest gen1 modules i currently have are 52Ah. I have 2 other packs i have not tested yet.
> ...


Or I rent a car and go on a road trip to Kansas City.


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> ... what would I be looking at for kwh?


That's 46 of the 48 modules, so 23 kWh of the original 24 kWh battery. If you start with a 30 kWh battery from a 2016 Leaf, you would have 96% of that or 28.7 kWh. All of these capacities are nominal in new condition, not actually usable.


----------



## brian_ (Feb 7, 2017)

When I realized that nearly an entire Leaf battery would fit (the same thing suggested by GreenTec Auto), I went back to look at the weight...


Jimbo69ny said:


> *Weight:*
> Batteries:
> 92s31p = 2,852 cells
> 2,852 x 45 grams = 128,340 grams aka 282.94 lbs
> ...


A Leaf battery is somewhat heavier, and any configuration that fills that box with lithium cells will be similar.

Is there anything planned to allow the RAV4 to handle this load, in addition to passengers and cargo? What's the payload capacity of the vehicle?
The additional battery is behind the rear axle, so it will especially load the rear axle... what's the rear axle load when empty and the Gross Axle Weight Rating?


----------



## Kevin Sharpe (Jul 4, 2011)

GreenTecAuto said:


> Leaf cells are not thermally managed. so there will be no cooling you can do other than blowing over them with a fan. Im not sure how warm they will get.


Leaf cells do not require any thermal management (other than not charging below -20C).

The longest continuous Leaf trip to date is 1652 miles, 56 hours, with 33 rapid charging sessions and they had no problem with overheating (see here).


----------



## Kevin Sharpe (Jul 4, 2011)

brian_ said:


> Keep your mind open to alternatives


Has anyone suggested a battery trailer? That's an awful lot easier to modify as new batteries become available


----------



## Kevin Sharpe (Jul 4, 2011)

brian_ said:


> A Leaf battery is somewhat heavier


Don't forget that it's possible to rewire Leaf modules so that 2S2P becomes 4S, delivering a battery with half the weight/volume/capacity. It's not easy but might be an option that does not require the vehicles suspension to be upgraded 

See photos here.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> Yup, this is why I dont think I will need a battery heater. I have a timer to charge my car in the morning. Charging warms them up, then of course driving does too.


I'm not sure where you live but most 18650 chemistries cannot charge below 0C without dendrite formation. FYI Nissan have stated that the chemistry used in the Leaf modules tolerates temperatures down to −20°C (see here).

It's interesting to note that some Model 3 owners are reporting issues in extreme cold because the car does not have a dedicated battery heater (it recycles waste heat only). This might be something to consider in your design.


----------



## brian_ (Feb 7, 2017)

Kevin Sharpe said:


> Don't forget that it's possible to rewire Leaf modules so that 2S2P becomes 4S, delivering a battery with half the weight/volume/capacity. It's not easy but might be an option that does not require the vehicles suspension to be upgraded
> 
> See photos here.


Good idea, and probably a wise compromise, but in this case the stated desire appears to be for maximum capacity within the available space.


----------



## brian_ (Feb 7, 2017)

brian_ said:


> Is there anything planned to allow the RAV4 to handle this load, in addition to passengers and cargo? What's the payload capacity of the vehicle?


Although the RAV4 EV owners manual does not provide any of this information, it will be on the placard on the driver's side door frame.

I did find one non-authoritative source:
_Autoblog: Compare 2014 Toyota RAV4 EV - Details_
It shows the same values for all three model years (2012 to 2014) of the RAV4 EV using Tesla components:
Curb Weight = 4,032 Lbs.
Payload = 973 Lbs.​I think these are pretty good (and they imply a GVWR of 5,005 lb), but by the time over 600 pounds of extra battery is added to the vehicle (leaving less than 373 pounds of payload), and the driver's weight is subtracted from that reduced payload, the cargo volume might not matter unless you're carrying foam or balloons.

Since the 2012 2WD base RAV4 has a curb weight of 3,360 lb and a payload of 1070 lb (implying 4430 lb GVWR, which agrees with a published spec of 2005 kg), the EV has increased GVWR so that it doesn't lose too much payload. Since the EV is much more tail-heavy, I suspect that the difference is all in rear GAWR; that suggests that the rear suspension is probably already pushed to it's practical limit, so an upgrade is not likely feasible.


----------



## Kevin Sharpe (Jul 4, 2011)

At the 2014 EVCCON (here) a gentleman traveled across country in a RAV4 with a 'pusher' trailer used for range extension... basically it was an old beetle chassis with the front wheels removed that would push the RAV4 when the ICE was running  I drove it at 60 mph down the freeway and it was very effective and gave good mpg apparently.

I know this is not the subject of this thread but this trailer gave the RAV4 almost unlimited range while having no impact on the loading capability or practicality of the vehicle


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> At the 2014 EVCCON (here) a gentleman traveled across country in a RAV4 with a 'pusher' trailer used for range extension... basically it was an old beetle chassis with the front wheels removed that would push the RAV4 when the ICE was running  I drove it at 60 mph down the freeway and it was very effective and gave good mpg apparently.
> 
> I know this is not the subject of this thread but this trailer gave the RAV4 almost unlimited range while having no impact on the loading capability or practicality of the vehicle



Oh thats funny. I have heard about that guy. Ive never seen his trailer though. I wanted to have something like a motorycle trailer with an engine on it or a motorcycle swingarm attached to an engine. Unfortunately no one will build it for me. Everyone tells me how unsafe it is. I dont weld so Its not something Id be able to do myself. But yeah, I have thought about it a lot. I figured if it was geared only for highway use, had control of the throttle inside the car, and was mounted to a solid bar into the trailer hitch (no ball, no risk of turning), it would be safeish.


----------



## Jimbo69ny (Feb 13, 2018)

As for all the other comments,
Im not really looking back at a different OEM battery. I thought about it but they dont have good power to weight ratios. I can build an 18650 pack that is lighter and has more power.

I have still toyed with the idea of the Smart packs and connecting them to the existing Tesla cooling system but I dont really want to cut the floor pan of the car. The car is so rare and I want to keep permanent alterations to a minimum. So far I havent done anything that I cannot undo. 

As for weight, if I have to Ill add stiffer springs. I wont know until I am done. I am guessing it will be around 300-400 lbs by the time I am done. I dont think that is very bad. 

I think that was it.


----------



## Jimbo69ny (Feb 13, 2018)

Ill add that if some new battery comes out that is better than the 18650 between now and the time I order my cells, I will reconsider the plan. But for now it seems to be the best option.


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> I am guessing it will be around 300-400 lbs by the time I am done.


You calculated 628 pounds yourself - what has cut the system weight in half since then?



Jimbo69ny said:


> As for weight, if I have to Ill add stiffer springs. I wont know until I am done.
> ...
> I dont think that is very bad.


What makes your think that? If you don't understand that there are many factors other than spring stiffness, then I think that you really need to consult with someone (including this forum) with more understanding of automotive technology.


----------



## Jimbo69ny (Feb 13, 2018)

brian_ said:


> You calculated 628 pounds yourself - what has cut the system weight in half since then?
> 
> 
> What makes your think that? If you don't understand that there are many factors other than spring stiffness, then I think that you really need to consult with someone (including this forum) with more understanding of automotive technology.


Ugh. If I had a dime for everytime someone wasnt supportive of my project.... LOL

I am guessing on the weight. Either way, it will be lighter than adding prebuilt OEM cells.

I know about the springs because someone else did the same thing to their Rav4 EV using different batteries and he said the car didnt sag much.


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> I wanted to have something like a motorycle trailer with an engine on it or a motorcycle swingarm attached to an engine. Unfortunately no one will build it for me. Everyone tells me how unsafe it is.


They have a good point. Do you understand the issues with these devices?



Jimbo69ny said:


> I figured if it was geared only for highway use, had control of the throttle inside the car, and was mounted to a solid bar into the trailer hitch (no ball, no risk of turning), it would be safeish.


I agree that a pusher device would only need to work at highway speeds, to meet the need for long highway range.

It might be safe-ish if the throttle were linked to braking and preferably a stability control system. I realize that a lot of people have used pusher trailers, but a lot of people do a lot of stupidly unsound things and get away with it most of the time - that doesn't mean that they are safe.

A non-articulated attachment is better for vehicle stability, but with a fixed (not steering) wheel it would also work if you only drove is a "straight-ish" path. How were you planning to accommodate turning around corners, and do you understand the implications of your design choice?


----------



## brian_ (Feb 7, 2017)

Jimbo69ny said:


> I know about the springs because someone else did the same thing to their Rav4 EV using different batteries and he said the car didnt sag much.


That answers my question: no, you have no idea of the consequences of overloading the vehicle. Please don't drive your crap on roads around me.



Jimbo69ny said:


> Ugh. If I had a dime for everytime someone wasnt supportive of my project.... LOL


I would say spending a substantial amount of time reading and considering your proposal, providing the feedback that you have requested, and offering options is pretty $%^&*() supportive... and that's everyone in this discussion.

I'm out.


----------



## Jimbo69ny (Feb 13, 2018)

LOL so many discouraging comments. You all must be miserable people in life.


----------



## diyevcar (Feb 19, 2018)

brian_ said:


> I would say spending a substantial amount of time reading and considering your proposal, providing the feedback that you have requested, and offering options is pretty $%^&*() supportive... and that's everyone in this discussion.
> 
> I'm out.


I wouldn't get worked up about it, he's a child or a person with the mental capacity of a child. It's not like he's going to start or complete the project... he's a 'gonna do this, gonna do that'.




Jimbo69ny said:


> LOL so many discouraging comments. You all must be miserable people in life.


Troll...


----------



## Jimbo69ny (Feb 13, 2018)

haha Im the troll. From the guy with 1 post.

I just thought I would share what I was working on. I thought you guys might enjoy it. I had no idea that it would be picked apart and instead recommended to build a dangerous "pusher trailer".

I cant delete the thread but I will message a moderator to delete it. I definitely did not mean to get so many people so upset. lol


----------



## diyevcar (Feb 19, 2018)

Jimbo69ny said:


> haha Im the troll. From the guy with 1 post.
> 
> I just thought I would share what I was working on. I thought you guys might enjoy it. I had no idea that it would be picked apart and instead recommended to build a dangerous "pusher trailer".
> 
> I cant delete the thread but I will message a moderator to delete it. I definitely did not mean to get so many people so upset. lol


Congratulations, after being a lurker for many years, your posts were so abrasive in reply to people helping you, that I had to join. I doubt the mods will delete the thread.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> I just thought I would share what I was working on. I thought you guys might enjoy it. I had no idea that it would be picked apart and instead recommended to build a dangerous "pusher trailer".


Members of this forum have been trying to help you. Brian for example has used his considerable mechanical knowledge to explore possible issues with weight distribution and it's impact on your vehicle. I've tried to make you aware of how challenging 18650's are when used in a vehicle application and I'm desperate to avoid a fire in a DIY conversion because of the potential impacts on legislation (in Europe for example we already have much tougher legislation than the US).

With regards to the "pusher trailer" I included it as a curiosity because it allows the RAV4 to have extended range without impacting the existing vehicle. I'm not suggesting you copy this approach but rather consider a battery trailer given you want to add 30-40kWh and ~600lbs to the car.

FYI here is a real world battery trailer example (4620 18650s, 42kWh, 750lbs);


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> Members of this forum have been trying to help you. Brian for example has used his considerable mechanical knowledge to explore possible issues with weight distribution and it's impact on your vehicle. I've tried to make you aware of how challenging 18650's are when used in a vehicle application and I'm desperate to avoid a fire in a DIY conversion because of the potential impacts on legislation (in Europe for example we already have much tougher legislation than the US).
> 
> With regards to the "pusher trailer" I included it as a curiosity because it allows the RAV4 to have extended range without impacting the existing vehicle. I'm not suggesting you copy this approach but rather consider a battery trailer given you want to add 30-40kWh and ~600lbs to the car.
> 
> FYI here is a real world battery trailer example (4620 18650s, 42kWh, 750lbs);


Me posting telling you guys about my project, then being told to do 2 completely separate things is not help.

Next time you book your vacation to the Caribbean, tell me about it so I can call you stupid and tell you to go to Russia in the winter instead. Then I'll say "I'm not being an asshole, I'm just trying to help......"

And your assumption that I haven't considered any the fire safety, weight, or any other details is insulting. I have been mulling over this project for a long time. I have spent a lot of time researching these cells and what I want to do. 

I guess I am totally naive but I thought you guys would be genuinely interested. I had no idea you would pick apart the project, second guess my decisions, call me stupid, and tell me to do something completely different.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> your assumption that I haven't considered any the fire safety, weight, or any other details is insulting. I have been mulling over this project for a long time. I have spent a lot of time researching these cells and what I want to do.


Your plan to place an air cooled 600lb 18650 battery within the passenger compartment of a car tells me you are naive. Your comments about extinguishers and sealing the battery during a fire are beyond naive. I support crazy ideas in principle (I like the "pusher trailer") but think we know enough about 18650s to avoid the death trap that you are proposing.

FYI I looked seriously at the RAV4 as a DIY project and decided the way to go was to replace the existing battery. This would not only have no impact on the inside of the car but would also give you at least 850lbs to play with... when combined with rapid DC charging it would be an awesome upgrade


----------



## Jimbo69ny (Feb 13, 2018)

There are thousands of people who have done the same thing (build packs out of 18650 cells). One guy who added batteries to his Rav 4 and and there is an aerospace engineer designing an add on pack for the same exact location using the same exact cells that will be sold for the Rav 4 ev. 

I’m sure that you will tell me that you already have, and that everyone else is nuts, but check out YouTube. There are literally hundreds of people using these cells in their home and cars. If you use fuses on the cells and a BMS this can be done. Sure everything is a risk. But lots of people are using these cells and doing great. Most of the people doing this are using recycled battery cells which I would say IS riskier. I will be using brand new cells. 

Regardless. This was my build thread that I wanted to post about my progress on. I am fine with trailers, pushers and other batteries. I might even try one of those projects someday. But that was not what this thread was about. Now it’s totally cluttered with your opinions about completely separate options.


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> Jimbo69ny said:
> 
> 
> > your assumption that I haven't considered any the fire safety, weight, or any other details is insulting. I have been mulling over this project for a long time. I have spent a lot of time researching these cells and what I want to do.
> ...


Years ago when I first started looking at this that was my first idea too. However it is not possible. There is no way to replace the exsisting battery pack. The existing pack is inches thick, similar to the Tesla modules but totally different. Different size, different shape, different BMS, different configuration. If you know about Tesla modules you know that you cannot take them apart without damaging them so you can’t simply upgrade the 2600 mah cells to 3400mah cells. 

IF you were somehow able to make it work (which you can’t) you would need to figure out the OEM CAN and somehow use it or you would get a ton of warning lights. IF you did it and somehow got 16 Tesla modules into the Rav 4 battery box (which isn’t possible), there are a ton of Rav 4 ev specific components that you could fry. These parts are extremely rare and hard to find because they aren’t used in any other car on the planet. 

But great idea! I support you for trying it. Let me know how it goes!


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> There is no way to replace the exsisting battery pack. The existing pack is inches thick, similar to the Tesla modules but totally different.


iirc the six 'large' modules in the RAV4 EV each contain 576 18650s whereas the Model S Module has 444 or 516 depending on the version. I believe the Model S modules are smaller than the RAV4 modules but it would be good to have this confirmed. Has anyone produced a dimensioned drawing of the existing RAV4 battery pack?


----------



## Jimbo69ny (Feb 13, 2018)

Kevin Sharpe said:


> iirc the six 'large' modules in the RAV4 EV each contain 576 18650s whereas the Model S Module has 444 or 516 depending on the version. I believe the Model S modules are smaller than the RAV4 modules but it would be good to have this confirmed. Has anyone produced a dimensioned drawing of the existing RAV4 battery pack?


You "believe"? Maybe YOU should do YOUR research before coming at me with your "solutions".

Each of the Rav4 EV battery packs are not the same. There are 4 larger packs and 4 smaller packs. None of which are the same dimensions or make up as any other Tesla pack.

The Rav4 battery pack is a 92s48p pack. No other Tesla pack is the same. The closest OEM Tesla pack is the Smart module as stated previously.

The Tesla modules that you commonly see on ebay, such as this one, https://www.ebay.com/itm/Tesla-Mode...ash=item3d144e48ff:g:OSkAAOSwh-1W5acD&vxp=mtr are 6s74p. I would need 15.44 of them in series in order to get to the voltage of my Rav 4 EV. 15 x $1400 is $21,000. So that is heavier, larger and way more expensive than what I am doing. But if you were still thinking that you could fit them into the existing battery location (more power to you) you need to figure out how to fit 16 modules in an area that previously held 8. Whilst still leaving room for contactors, bms, wiring and connectors.

But go ahead, because you seem to know so much more than me. Please post your thread about your project so we can all follow along....


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> There are 4 larger packs and 4 smaller packs.


RAV4 packs I've seen have 6 'large' and 4 'small' modules but you're clearly the 'expert' here 

My proposal is that you replace the existing battery with 8 of the 6.25kWh modules from the Tesla Model S/X 100D giving you 50kWh in total. When combined with rapid DC charging I suspect this would be a big improvement on the current vehicle. I appreciate this is not the capacity increase you seek but it would have less of an impact on the load capacity of the vehicle and still be close to your budget. With regards to battery voltage I suspect that most RAV4 systems would cope with the Model S/X 364V nominal, 403V charge, given your stated target range is 382-386V.

With regards to RAV4 CAN hacking this is a DIY forum and I'm sure someone would be able to help you. Whatever path you take you're going to need to integrate the BMS with the RAV4 systems.


----------



## Duncan (Dec 8, 2008)

Jimbo69ny said:


> There are thousands of people who have done the same thing (build packs out of 18650 cells). One guy who added batteries to his Rav 4 and and there is an aerospace engineer designing an add on pack for the same exact location using the same exact cells that will be sold for the Rav 4 ev.


There have been hundreds - not thousands - of people who have pontificated about doing that

I would be surprised if as many as 10 of them have actually produced working battery packs in actual vehicles


----------



## Jimbo69ny (Feb 13, 2018)

I know this thread really went down hill quickly. I dont know if anyone cares but here is an update....

Instead of editing the first post I decided to post the update here. This has been an amazing project so far and I am learning a lot. I dont have a lot of money into it so far but I do have a fair bit of time invested. I am nervous to take the big step of purchasing the 18650 cells. As you will see in my following post its going to cost me around $11,300 for the cells. That's a lot of money to lose if I fuck up......

*Goal:*
I'd like the largest battery possible but I only want to sacrifice the lower storage space in the rear cargo area.

*Time frame:*
I want to get it done by NDEW in September 2018

*Battery Plans:*
I plan on using brand new lithium ion LG MJ1 18650 battery cells. Each cell is rated at 3500 mah and 10 amps constant. Here they are, https://liionwholesale.com/products...at-top-wholesale-discount?variant=11564550916
I can fit 9 modules in a vertical formation in the lower cargo area if I cut out the floor pan. I plan on matching the OEM pack to keep voltage the same. The OEM pack is 92s48p, I am planning on building a 92s32p pack. I can fit 320 cells in each module, 2,944 total cells in this configuration. The floor of the cargo area will be raised about 2 inches. 

*Battery Box:*
I'll hire a welder to build me an aluminum battery box. I plan on mimicking the details Tesla incorporated into its pack. Each of the 9 modules will be as isolated from the other packs as much as possible. ¼” Aluminum will be used on the outer walls. Inside I will have baffles to direct airflow in order to cool the cells. I will use mica sheets to insulate the interior baffles. The baffles will also give it some structural rigidity in case I am rear ended. I have also looked into a fire extinguisher system using Firebane which super cools cells that are going thermal. Lastly, I want to try to incorporate Tesla’s vent plugs if I can get my hands on any.





































*Heating/Cooling:*
I am not planning on installing a heater. I am going to see how it goes. If I need to add one later I will go with a PTC heater.
To circulate air through the baffles I have 3 fans on the right sid of the box sucking air out of the box. I was told by my engineer brother that 3 or even 6 fans might not be enough. Time will tell. 

*Capacity: *
(Assuming 92s32p) 
If each cell is 2600 mah, that would be 83,200 mah or 83.2 AH (2600 x 32)
386 volts x 83.2 AH = 32,115.2 WH aka 32.1 kwh battery capacity 

If each cell is 3400 mah, that would be 108,800 mah or 108.8 AH (3400 x 32)
386 volts x 108.8 AH = 41,996.8 WH aka 41.9 kwh battery capacity

Minus 10% as unusable =
28,903.68 WH aka 28.9 kwh battery capacity
37,797.12 WH aka 37.7 kwh battery capacity

*Range:*
Weight of car / 10 = watt hours per mile
Rav = 4500lbs
4500lbs / 10 = 450 wh per mile
28,903.68 kwh / 450 wh per mile = 64.2 miles with 2600 mah cells
37,797.12 kwh / 450 wh per mile = 83.99 miles with 3400 mah cells

OEM rating would be:
41,900 / 450 wh per mile = 93.111 miles with OEM 2600 mah cells
41,900 / 350 wh per mile = 119.714 miles with OEM 2600 mah cells *more realistic*

Theoretical realistic range with additional pack:
28,903.68 / 350 wh per mile = 82.58 miles with 2600 mah cells
37,797.12 / 350 wh per mile = 107.99 miles with 3400 mah cells

Plus existing range from 41 kwh OEM pack!
119.714 miles + 82.58 miles = 202.29 Miles with 2600 mah cells 
119.714 miles + 107.99 miles = 227.7 Miles with 3400 mah cells


*Weight:*
Batteries:
92s32p = 2,944 cells
2,944 x 49 grams = 144,256 grams aka 318 lbs
Box = 100 lbs ish?
Body work = 60 lbs ish?
Other = 100 lbs ish?
578 lbs total?

*BMS/System monitoring:*
I haven't explored this yet so I dont know what options are out there. I would like a unit with a display that shows voltage, temp, amp hours, etc of the batteries.

*Cost:*
92s32p = 2,944 cells
2600 mah $2.80 x 2,944= $8,243.20
3400 mah $3.80 x 2,944= $11,187.20
Plus $100 for shipping

*Price per kwh:*
Only for the cells. No box or system parts.
2600 mah - $8,343.20 / 28.9 kwh = $288.69 per kwh
3400 mah - $11,287.20 / 37.7 kwh = $299.40 per kwh!

*Parts To Date:*

Contactors $61
https://www.ebay.com/itm/Tyco-TE-Re...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
Inertia Switch off ebay $13
20 Dead 18650 cells off ebay $13
2 - 400v 250 amp fuse off ebay $15 each
(3) Panaflow high speed fan NMB120mm FBA12G12H $20
https://www.ebay.com/itm/NMB120mm-F...396a6f96c:g:s~sAAOSwjyhaTFZI&autorefresh=true

3 - Temperature fan control modules $2
https://www.ebay.com/itm/W1209-12V-...var=413176014560&_trksid=p2057872.m2749.l2649
Gigavac Hbd41AA $49
http://www.gigavac.com/shop?title_op==&title=hbd41aa1
3 - M22x 1.5 cable glands 5 pack for $8.85
https://www.amazon.com/gp/product/B071VT8NLM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Digital energy monitor $27.90
https://www.ebay.com/itm/400V-300A-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649


2 Gauge shielded EXRAD wire from iewc. (EXRAD02-XLEOBS-5) 35 feet $6.25/foot. Purchased 35 Ft = $218.75 + shipping
http://evwest.com/support/Shielded_Battery-Irradiated_XLE.pdf

Electrical box $13.49
https://www.amazon.com/gp/product/B071FKFK6W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Crimp ring terminals $20.02
https://www.amazon.com/gp/product/B073FB2Y4S/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

Automotive 12v relays $11.99
https://www.amazon.com/gp/product/B00RWV470O/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

8 Gauge wire $9.99
https://www.amazon.com/gp/product/B01LY5N276/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Fuse panel $9
https://www.amazon.com/gp/product/B00QMTAZ1W/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Ground distribution block $4
https://www.ebay.com/itm/1x-4-Way-C...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Lots and lots of 18650 cell holders $100-$200ish
https://www.amazon.com/gp/product/B01HQB085C/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Aux battery switch $20
https://www.ebay.com/itm/CH4x4-Toyo...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Misc wire $12
https://www.ebay.com/itm/16-AWG-Gau...var=492184468583&_trksid=p2057872.m2749.l2649

12 volt fuse holder $2
https://www.ebay.com/itm/4-6-8-Gaug...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

¾” and 11/2” shrink wrap with adhesive around $20


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> *Price per kwh:*
> Only for the cells. No box or system parts.
> 2600 mah - $8,343.20 / 28.9 kwh = $288.69 per kwh
> 3400 mah - $11,287.20 / 37.7 kwh = $299.40 per kwh!


For the benefit of anyone reading this thread and considering the 18650 self build option, Damien recently paid 600 euros (740 USD) for a Chevy Volt pack, and I've just paid 15,000 euros (18,400 USD) for a 100kWh Tesla pack 

Given these include BMS, heating/cooling, and are already packaged, OEM solutions offer *much* better value for money;

$18,400.00 / 100kWh = $184 per kWh


----------



## Jimbo69ny (Feb 13, 2018)

Wow where did you find a 100kw pack? Ive been keeping my eyes open for a pack to make a trailer out of. I found a 85kw pack but the seller wanted $24,000.

Those are rare finds and you got a smoking deal!


----------



## Yabert (Feb 7, 2010)

Kevin Sharpe said:


> Given these include BMS, heating/cooling, and are already packaged, OEM solutions offer *much* better value for money


+1
OEM battery is the way to go. High quality, packaged and at around 80 to 200$ / kWh there are the best solution.


----------



## Jimbo69ny (Feb 13, 2018)

Yabert said:


> +1
> OEM battery is the way to go. High quality, packaged and at around 80 to 200$ / kWh there are the best solution.


The way to go for some people... They are heavier than my set up. Tesla 85kw modules weigh 58 lbs each. I would need 16 of them to reach to reach the voltage I need for my project. 16 x 58 lbs is 928 lbs. 16 is also the number of modules in a tesla 85 kw pack. You could take apart the box and only use the modules stacked on top of each other but that isnt safe. My set up will weigh 500 - 600 lbs and be much safer than stacking Tesla modules without a box. 

Also, for my project, I dont want to lose my entire cargo area. With Tesla or any other manufacturers packs, I would lose all of my interior space. Secondly, I dont think my car could handle another 1000lbs of rear weight.

So yeah, there are a lot of options out there to use for your projects. Again, this thread is about MY project and what I am using.


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> I would need 16 of them to reach to reach the voltage I need for my project. 16 x 58 lbs is 928 lbs.


Don't forget that you can modify the Tesla modules so that you only need 8 for the same total voltage


----------



## Yabert (Feb 7, 2010)

460 lbs and over 40 kWh at 360V.... Ding, ding, ding! We have a winner.

Jim, if you want to do your project to learn or for fun, that make sens. But the quicker and the most economical way to add range at your SUV is OEM battery.


----------



## Jimbo69ny (Feb 13, 2018)

Yabert said:


> 460 lbs and over 40 kWh at 360V.... Ding, ding, ding! We have a winner.
> 
> Jim, if you want to do your project to learn or for fun, that make sens. But the quicker and the most economical way to add range at your SUV is OEM battery.


Not sure what you're talking about. I am not going with OEM cells and 360 volts isnt high enough. My system peaks at 386 volts. The closest match would be Tesla Smart car cells but those would only give me a 90s configuration, I need 92. I cant fit those in my lower cargo area even with cutting the floor out and welding in a new pan, they are still 1.5" too long.


----------



## Jimbo69ny (Feb 13, 2018)

Yabert said:


> 460 lbs and over 40 kWh at 360V.... Ding, ding, ding! We have a winner.
> 
> Jim, if you want to do your project to learn or for fun, that make sens. But the quicker and the most economical way to add range at your SUV is OEM battery.


And again, my MAIN GOAL is to ONLY use my lower cargo area. I use my car for work and I dont want to fill the cargo area with an OEM battery.

This is so frustrating. Everyone tells me to do something completely different. 

I am done posting here. This is a waste of time.


----------



## Karter2 (Nov 17, 2011)

More unwanted suggestions ,..or saving you work ?.. But..
...what is the point of using "Tesla style". fire vent valves, when you have 3 (or 6) fans blowing air through the pack ?
PS... The "smart" guys are not those who *have* all the best ideas,...they are the ones who *use* all the best ideas


----------



## tylerwatts (Feb 9, 2012)

Jimbo
Please keep sharing, I am impressed with your plans so far. 

I agree about the fans & vent however. No need for both! Is it a significant task to employ liquid cooling?


----------



## Kevin Sharpe (Jul 4, 2011)

Jimbo69ny said:


> Wow where did you find a 100kw pack?


They come up occasionally at the breakers but you need to build a relationship and call regularly to hear about them. In six months this is the first one that I've found within the EU.



Jimbo69ny said:


> I found a 85kw pack but the seller wanted $24,000


That's crazy 'retail' pricing... even on eBay you can get cheaper modules in the US today (here). In Europe we typically pay 12,000 Euros (14,000 USD) for 85kWh packs direct from the breakers.


----------



## Kevin Sharpe (Jul 4, 2011)

tylerwatts said:


> I agree about the fans & vent however. No need for both! Is it a significant task to employ liquid cooling?


My preference is liquid cooling because it's known to work. One of the challenges with air cooling is removing dust so that the air passages don't get blocked over time.


----------



## arber333 (Dec 13, 2010)

Well there is another way. At least i see this quite clearly. Do not mix cells of different chemistry/model in the same car directly. Not worth the risk. 

Rather you can make a pack, whatever voltage it suits you and then built a charge pump using existing buck or boost charger topology. I think Jhuebner inverter can be used as a boost charger from lower pack to higher with considerable power.

What i am trying to build for Ampera:
1. 4x tesla cell modules for 100Vdc at 20kW
2. charge pump from 100Vdc to 360Vdc main battery the way Prius converter works. I may even use prius inductor
3. BMS and voltage regulation for application

While car would be driving charge pump would be operational in boost mode and would give at least 10kW of power towards main battery. That would extend my range to 150km when driving reasonably fast. 

While car would be stopped i could bring 3phase rectified 600V from L2 EVSE to other side of charge pump which would stepp it down to 100Vdc and fast charge additional pack. 

That way i would not need to equalise battery packs and perform other such miracles. And dont forget your 18650 cells would have different voltage drop than your primary battery inducing phantom currents between packs that you cant control.


----------



## tylerwatts (Feb 9, 2012)

That's an excellent suggestion arber333. Worth considering and may actually simplify the project.

Jimbo

How much range would you give up assuming you stacked as many Tesla/Ravs/Smart modules horizontally in the boot space and used the remaining space to one side for the step up to main battery voltage? Does that make sense?


----------



## electro wrks (Mar 5, 2012)

arber333 said:


> Well there is another way. At least i see this quite clearly. Do not mix cells of different chemistry/model in the same car directly. Not worth the risk.
> 
> Rather you can make a pack, whatever voltage it suits you and then built a charge pump using existing buck or boost charger topology. I think Jhuebner inverter can be used as a boost charger from lower pack to higher with considerable power.
> 
> ...


Help me with the term (or translation) "charge pump". Is that a DC to DC converter? Are these available or easily buildable in these high power applications?


----------



## Capt Bill (10 mo ago)

Jimbo69ny said:


> If anyone has any input or suggestions I’m all ears.
> 
> Right now I am researching the effect of having two different capacity batteries. Seems as though the new one will have lower resistance and be the primary battery for the cars needs. Then when voltage drops the OEM pack will transfer voltage to the new pack. Is there anything wrong with that if that is actually the case? Do I need a battery isolator? I haven’t looked at them at all. Are there isolators available that can handle 325 amps and 386 volts?


I see this post is from 2018 (reading it 2022). Hits my interests button, as I had used Rav EV go by with almost dead battery, that somebody purchased before I could go look. ...Will study thread. Interested in how this project turned out. ... Bill from Northern California


----------

