# Cheap, fast and short distance build??



## Yabert (Feb 7, 2010)

Hi
The cheapest and easiest way to achieve your goal is with high discharge rate battery. You will can go fast, but not for long time.

Go with used forklift motor and build your controller, find a used controller or buy Kelly or some other cheap contoller.

Because you need high speed, you should go with a 144v battery pack.
You can probably find high rate lead battery, but I think you should need buy high discharge rate lithium if you need to drive your car more than a year without change your battery pack (Lead). More $ first investment, but cost less at long term.
A small 3-4 Kwh battery pack can do the job.
Ex: Headway 38120s, 144v x 20Ah = 2.9 Kwh. 90 cells = 1600$

The total cost will be relatively high (2500-4000$) because you need high speed.

Good luck


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## peppp (May 9, 2011)

Yabert said:


> Hi
> The cheapest and easiest way to achieve your goal is with high discharge rate battery. You will can go fast, but not for long time.
> 
> Go with used forklift motor and build your controller, find a used controller or buy Kelly or some other cheap contoller.
> ...


wait, what ?

Yabert, can you help me with that math in my thread please? My car is 1500 lbs and I'm starting to think I can go for a LiFePo4 pack ^^

thread here: http://www.diyelectriccar.com/forums/showthread.php/another-newb-project-peppp-s-low-58755.html


And sorry for derailing yours, kinetisist


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## ev_nred (Sep 23, 2009)

hello,
this looks like it could be a fun project! I have a battery suggestion if you don't mind... what about a lipo pack! 36 of these http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9176!
they each pack about 120wh (6sx4v=120wh) total would be more then 4kw! I would use 6 of these in series and six in parallel, 144volt and 600amp continuous and 900amps peak! Total Wight of such a battery pack would be under 30kg! total cost would be about $1600! 173hp before efficenticy loses! would thus be a good battery pack hooked up to a 9"hv motor? why or why not 
thanks,
Jacob R


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## rwaudio (May 22, 2008)

ev_nred said:


> hello,
> this looks like it could be a fun project! I have a battery suggestion if you don't mind... what about a lipo pack! 36 of these http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9176!
> they each pack about 120wh (6sx4v=120wh) total would be more then 4kw! I would use 6 of these in series and six in parallel, 144volt and 600amp continuous and 900amps peak! Total Wight of such a battery pack would be under 30kg! total cost would be about $1600! 173hp before efficenticy loses! would thus be a good battery pack hooked up to a 9"hv motor? why or why not
> thanks,
> Jacob R


I use the same series of cells in my RC helicopter. They do work well, but I'd make sure you have a good BMS, they don't do so well when over/under voltaged. The cycle life of these cells also isn't as good as LiFePO4, expect a few hundred cycles instead of a few thousand.


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## Batterypoweredtoad (Feb 5, 2008)




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## kinetisist (Oct 24, 2008)

Well thanks for the input so far ... I have to say that I am lost on the math 6s x 4v = 120wh??? 
I found these batteries .. turnigy 4.5 $26.38
*Spec.
Minimum Capacity: 4500mAh
Configuration: 2S2P / 6.6v / 4Cell
Constant Discharge: 30C
Peak Discharge (10sec): 40C
Pack Weight: 317g
Pack Size: 139 x 44 x 25mm
Charge Plug: JST-XH Discharge plug: 4mm Bullet-connector

set these in parallel sets of 11 = 145v .. 22 pack =$580
do this twice = 44 packs = $1160

My other question is how do you setup the wirng for the charging of this type of battery

I am also still looking for a motor..Any help ??? in far north of California
thanks

*


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## kinetisist (Oct 24, 2008)

You posted this why???



Batterypoweredtoad said:


>


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## rwaudio (May 22, 2008)

kinetisist said:


> *set these in parallel sets of 11 = 145v .. 22 pack =$580*
> *do this twice = 44 packs = $1160*
> [


I'm not sure I follow your math...
using 6.6v packs it would take 22 series packs to make 145v (perhaps that's what you ment)
Put two strings of those together and you have a 145v 9AH battery (again perhaps that's what you ment)
That gives you 270A continuous and 360A peak for about 50hp peak at the wheels.
With reasonable driving habits you could get 4-6 miles out of it easily, conservative driving perhaps a bit more.

Have a look at some headway cells, 90 of the 38120P cells would give you 145v and 16AH, with 400A of peak current for $1710 from Manzanita Micro.
Or 45 of the 16AH cells would give you 145v @ 16AH with 240A peak for $1440.

The headways would be MUCH easier to build a pack out of.


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## kinetisist (Oct 24, 2008)

What I meant was to hook 2 6.6v packs together in series = 13.2v then build a set of 11 in parallel would = 145.2v ... How does the math work for poweron this??



rwaudio said:


> I'm not sure I follow your math...
> using 6.6v packs it would take 22 series packs to make 145v (perhaps that's what you ment)
> Put two strings of those together and you have a 145v 9AH battery (again perhaps that's what you ment)
> That gives you 270A continuous and 360A peak for about 50hp peak at the wheels.
> ...


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## ev_nred (Sep 23, 2009)

hello,
you guys are right lipos do easily burst in flames! the headways will be easier to use but the lipos are lighter and more powerful! just explaining the pack that I posted has 6 cell in series charged at 4 volts each that 24 volts x 5amps=120wh! on second thought don't use lipos, they are dangers!!!!!! I am not legally responsible for any of this! 
good luck,
Jacob R
ps: use the headways


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## ev_nred (Sep 23, 2009)

hello,
for the motor I would use either this 9" 144 volt motor
http://kostov-motors.com/tractionmo...its/seriesdcmotorsforelectricvehicles/k9144v/
but this motor would be more ideal as when a motor is under volted it is more efficient (correct me if I am wrong) http://kostov-motors.com/tractionmo...its/seriesdcmotorsforelectricvehicles/k9220v/
best regards,
Jacob R


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## Yabert (Feb 7, 2010)

kinetisist said:


> *I am also still looking for a motor..Any help ???*


The cheapest way is to rebuild an old forklift motor.

If you can't find forklift motor, you will need to spend 1300-1700$ for a motor....
Spend this money on battery will be far better!


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## rwaudio (May 22, 2008)

kinetisist said:


> What I meant was to hook 2 6.6v packs together in series = 13.2v then build a set of 11 in parallel would = 145.2v ... How does the math work for poweron this??


Just a quick note, in series voltage adds, in parallel capacity adds.
Two 5v 10ah packs in series = 10v 10ah
Two 5v 10ah packs in parallel = 5v 20ah

peak power would be (sagged voltage * capacity * peak C rate)/746 = electrical HP
continuous power would be (sagged voltage* capacity * continuous C rate)/746 = electrical HP

Total Energy is (capacity * nominal voltage)

Distance you are going to move is Total Energy/Energy usage per mile

If you want 10 miles (safe capacity over your 6 mile requirement)
you would need: Total Energy = 10*Energy per mile
I'm going to pull a number similar to what other light conversions get which is 250wh/mile
So Total Energy = 10*250 = 2500wh, since Total Energy is (capacity * nominal voltage) 
If you want a 145v pack you will need ~17ah of capacity for 10 mile range at 250wh/mile.
If your energy usage per mile goes up, your range goes down, so if you add heat in the winter, headlights etc. you will want to account for that. 

Good luck with your project, keep reading and asking questions, there is a lot to learn.


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## Batterypoweredtoad (Feb 5, 2008)

kinetisist said:


> You posted this why???


Mostly because I think it is an amusing (even if slightly creepy) picture. The other reason is that from my few years of lurking in the EV and hobby world it is pretty apparent that batteries with chemistry similar to the Turnigys are more likely to burn when abused. Your situation requires some abuse, admittedly far less than the hobby guys give them, but the behavior under abuse is a valid concern. Something that has only been lightly touched on is if a box can be built to withstand a burn without toasting your vehicle with a reasonable budget. If you are interested in the Turnigys, I would contact Ron with the Electric Camaro. He claims to be involved in the development of cells with heavier gauge wiring and casing friendly to EV pack design.


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## kinetisist (Oct 24, 2008)

I got a quote for the battery pac based on the suggestions from a seller on ebay...I want to know what it would cost for a 144v 30Ah Lithium Battery LiFePO4 pack with a charger
We have two kinds of the item:
1. BMS protection board with LCD, with over-current protection: price USD2750,
2. only charging protection with a simple protection board: Price USD1920
Best regards!


*- asian-resources*com*

thank you


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## kinetisist (Oct 24, 2008)

Batterypoweredtoad said:


> Mostly because I think it is an amusing (even if slightly creepy) picture. The other reason is that from my few years of lurking in the EV and hobby world it is pretty apparent that batteries with chemistry similar to the Turnigys are more likely to burn when abused. Your situation requires some abuse, admittedly far less than the hobby guys give them, but the behavior under abuse is a valid concern. Something that has only been lightly touched on is if a box can be built to withstand a burn without toasting your vehicle with a reasonable budget. If you are interested in the Turnigys, I would contact Ron with the Electric Camaro. He claims to be involved in the development of cells with heavier gauge wiring and casing friendly to EV pack design.



thanks for the clarification .. if the lithium batteries are possibly that dangerous what else can we do that will yield range and weight savings?


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## ev_nred (Sep 23, 2009)

kinetisist said:


> thanks for the clarification .. if the lithium batteries are possibly that dangerous what else can we do that will yield range and weight savings?


hello,
do something like this to your car http://aerocivic.com/ lol but he is geting 96 mog so as for the battery, you could go with * these that would be 144volt at 32 amps http://stores.headway-headquarters....ttery-pack,/Detail.bok?category=BATTERY+PACKS thats 5grand, a cheaper alternative would be to order the battery cells yourself and build the pack yourself.... what you budget?
best regards,
Jacob R


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