# JAC'd up Beetle



## Harmon20 (Oct 5, 2017)

Had just enough time last night to get the meter out and check the battery pack. The LFP cell battery is putting out voltage to the upper deck control section. My analog meter jumped to around 430v for a while then slowly settled down to 360v over the course of about 10 seconds. I checked calibration on the 12v accessory battery and it looked good. So it looks like the cells are probably fine and I just need to figure out a way to get a charge in them.

Kind of odd that the pack rating is 304v but the meter is reading 360-430v, no? Why would that be?

I hooked up the accessory battery to see what would happen. Everything seems to work fine (other than the fact the drive has no go juice) despite the wreck. No warning lights on the instrument cluster aside from the fuel gauge, power lock and windows work, shift selector works as expected. Contacts in the battery pulled in as expected when turning on. Looks like a good donor.

I've got a 56v lithium charger for cordless tools. I'm considering splitting the cell battery up into sections and seeing if I can charge them with the cordless tool lithium charger.

Harmon


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## Harmon20 (Oct 5, 2017)

I got the battery case open to see what was going on inside. I was kind of hoping things would be more exposed and easier to work on, but I guess covered and safer is good too.














The plastic is covering what looks like bricks about 3x4x10 or thereabouts. The packs are connected by means of some thin plates. One plate goes down on the plastic, the tabs of the bricks fold down over the plate, the next plate goes down, hex phillips screws go through it all and include one BMS monitor ring terminal and safety clips to prevent the screws from backing out.













The BMS is ordered in four sets with an extra cable going to each 10th monitored "bat".













There are therefore only 40 BMS monitor cable assemblies.












Even though there are only 40 BMS leads the physical dimensions and layout suggest there are 60 bricks under this top. The plastic terminal covers are stamped with alphanumeric info - "A3-1.5", "B4-1.5", etc - and 60*1.5 = 40 so...I'm not sure what that means. Apparently there is a parrallel-serial arrangement rather than the straight serial I'd assumed. I think. I'd really hoped not to pull the entire array apart, but it looks like that's what I need to do to fully understand what's going on.

Harmon


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## Harmon20 (Oct 5, 2017)

I'm a little more informed now, but no less confused. I opened up the cell assembly and it turns out there are 40 packs. The reason I couldn't figure out the arrangement is that there are actually two different kinds of cell packs: opposing tabs and adjacent tabs. They are placed in the assembly to make the serial connections short.













I'm confuse by the voltages here. The array is "rated" at 304v. With 40 packs that means each pack is rated at 7.6v. 

Huh? Where does that number come from? A standard LiFePO4 cell produces 3-3.65v, minimum working level to max charge. That's no lfp cell I've ever heard of and nothing I can divide into 7.6v gets me in that range.

7.6v/2 = 3.8v
7.6v/3 = 2.533v

What's more, if I look at the spot welded tabs and looking through the bottom of the pack it appears that there are 5 cells in this brick.












The only battery I can find that is anywhere in the neighborhood of 7.6v is a SLA, and this doesn't appear to be anything like that. 












So I'm not sure how to charge these right now. I've got to get a new meter and see what each of these packs is actually putting out.

Any ideas what the charge voltage should be for these cells?

Harmon


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## brian_ (Feb 7, 2017)

I assume that the JAC is the previous version of their current IEV5 (which is the HFC7001AEV). Auto-CHE.com has a page of information about a bunch of variants ("batches") with links to more detailed pages for each of them. I suppose you already had that...

The Wikipedia article for JAC says they assembled Mitsubishi vehicles at one time, so it seem reasonable to guess that this car is largely a copy of some Mitsubishi model... although this might not matter since those would be the parts which you will not be using.


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## brian_ (Feb 7, 2017)

Perhaps most importantly, there are just empty spaces where the text suggests that there are supposed to be images. 

_Update_: I copied the URL for one of the images to a separate window, got a security warning from my browser (Chrome), told it to go ahead and risk problems, and now I see the images.


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## brian_ (Feb 7, 2017)

Harmon20 said:


> Maybe even this doodad:
> 
> 
> 
> ...


The marking appears to say "GPS GSM CAN"... so a combined GPS receiver and mobile data (the old GSM standard) transceiver, communicating with the rest of the car on the CAN network?


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## brian_ (Feb 7, 2017)

Harmon20 said:


> I think this is the onboard charger:


Presumably, based on the markings, that's the DC-to-DC converter, with 200+ VDC input.


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## Harmon20 (Oct 5, 2017)

brian_ said:


> Auto-CHE.com has a page of information about a bunch of variants ("batches") with links to more detailed pages for each of them. I suppose you already had that...


Yes, I had looked over that site I was, by far, the most informative of any site I'd found but it didn't make things any clearer for me at the time.

Looking back over _all_ the JAC electric vehicles they all say 3.2v cells, but the clue that got me to re-thinking things was that some of the vehicles (not necessarily cars) had battery rattings noted as things like "320v/304v". That 320v being the voltage of 100 3.2v LiFePO4 batteries got me to thinking...I count 40 packs with 5 cells each = 200 cells, a multiple of 100. Rather than being straight series as I thought, I need to check polarity on the cells. Quit assuming based on sight and verify. It could be there is a combination of series and parallel, even though it appears at a glance to be pure series. 

I already know that I have at least two tab configurations - opposing and adjacent - so I might also have two different polarity configurations. Two tabs on the left and the positive is on top, two tabs on the left and positive is on the bottom. That could allow for combo connection that appears to be a serial connection. I think.

If I actually have two parallel banks of 20 five-cell packs, or some other combo, then I can get to 320v. That's not the name plate rating, or even what my meter showed, but it is one of the figures listed on a handful of the JAC ev pages at auto-che.com

What it comes down to is I need to quit looking and assuming I know what's going on and put the meter to things to verify _everything_.

Harmon


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## Harmon20 (Oct 5, 2017)

brian_ said:


> Presumably, based on the markings, that's the DC-to-DC converter, with 200+ VDC input.


Yeah, my ignorance showing. I realized as I did more reading what I was looking at but never went back to change the post. I'll chalk it up to recording my enlightenment as I get into this project.

Harmon


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## Harmon20 (Oct 5, 2017)

brian_ said:


> Perhaps most importantly, there are just empty spaces where the text suggests that there are supposed to be images.
> 
> _Update_: I copied the URL for one of the images to a separate window, got a security warning from my browser (Chrome), told it to go ahead and risk problems, and now I see the images.


I put the image links in incorrectly, using https instead of http. I use a self-signed security certificate and forgot that the rest of the world's browsers might have a problem with the cert my browser was specifically told to trust. Should be fixed now. Thanks for the heads-up.

Harmon


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## Harmon20 (Oct 5, 2017)

OMG, I'm an idiot. Those bricks have to be 5 parallel cells because of the way they're tabbed. 

Harmon


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## Harmon20 (Oct 5, 2017)

OK, I bought a new meter and confirmed everything. All 40 packs are five paralleled cells for 3.2V (currently) and the packs are all connected in series.

What I don't get is why the placard rating on the battery cabinet and the specifications listed at auto-che.com say the battery voltage is 304v.

40 * 3.2v = 128v
40 * 3.6v = 144v

I don't get where the 304v is coming from. Maybe that's the amount of voltage you have to push through it to charge?

At least I know any LiFePo4 charger will work, just link cells in series to the charger's capacity. Any recommendations?

Harmon


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## brian_ (Feb 7, 2017)

Harmon20 said:


> I put the image links in incorrectly, using https instead of http. I use a self-signed security certificate and forgot that the rest of the world's browsers might have a problem with the cert my browser was specifically told to trust. Should be fixed now. Thanks for the heads-up.


That matches what I saw.


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## brian_ (Feb 7, 2017)

Harmon20 said:


> OK, I bought a new meter and confirmed everything. All 40 packs are five paralleled cells for 3.2V (currently) and the packs are all connected in series.
> 
> What I don't get is why the placard rating on the battery cabinet and the specifications listed at auto-che.com say the battery voltage is 304v.
> 
> ...


Each 5-cell pack must be either all in parallel or all in series; both a visual assessment and the pack voltage confirm that it is parallel.

That makes sense, but...


Harmon20 said:


> I don't get where the 304v is coming from. Maybe that's the amount of voltage you have to push through it to charge?


That sounds like an impossibly high charging voltage for that configuration, and an unreasonably low operating voltage for a modern production EV. I note that the input voltage range on the DC-to-DC converter is from 200 V to something... presumably higher, but you could check. And you already measured over 300 volts from the fully connected set, right?

I'm confused.


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## Harmon20 (Oct 5, 2017)

Yes, I'm confused as well. I'm thinking my meter is suspect so maybe the readings are not actually in the high 300v range. I've acquired a new meter but the pack was dismantled by the time I got it so I haven't confirmed the total series voltage yet.

I finally found a charger on AliExpress. I'll have to do some modification to it to work on US power, but at least I'll have a proper charging system for the car's systems. 

I might even see if I can use the control system in the charger and convert it from a Mode 2 to a Mode 3 charger. I found a detailed spec sheet for the GB20234 standard. The spec in combination with a working device communicating according to the GB standards I might be able to reduce my charge times.

When the charger gets in I'll connect the car and see if I can get this thing going and use the new meter to sort out what's going on.


Josh


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## Harmon20 (Oct 5, 2017)

I obtained some CC-CV 6A chargers from Battery Space to try to get some power in the cells while I wait for the slow boat from China.

They don't seem to act as advertised, but maybe I don't know what I'm talking about. Set me straight if I'm confused. 

They seem to be letting current and voltage float and never reach the rated 6A. They do limit voltage to 3.6v and shut off at [email protected], so maybe I don't know what is supposed to happen. 

I thought a charge cycle was supposed to look like this:










(Yes, I know the numbers are off for a single LFP cell. It's just the curves I'm interested in.)


But instead I get this:











The voltage curves are 3.1v to 3.6v; I just left off the labels. The graph covers 25:20hr.

My data is HERE. (3kb CSV file)

It takes 24hr to charge when my 62Ah cells should be taking around 14-15hr @ 6A.

Do those curves look like they should for a CCCV charger?

Harmon


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## rev0 (Oct 7, 2017)

Harmon20 said:


> They seem to be letting current and voltage float and never reach the rated 6A. They do limit voltage to 3.6v and shut off at [email protected], so maybe I don't know what is supposed to happen.
> 
> I thought a charge cycle was supposed to look like this:
> 
> ...


What are you using to measure the voltage? I highly doubt the current would have a smooth curve if the voltage were really abruptly changing like that. I have a feeling there's some rounding going on with the measurement tool.


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## Harmon20 (Oct 5, 2017)

rev0 said:


> What are you using to measure the voltage? I highly doubt the current would have a smooth curve if the voltage were really abruptly changing like that. I have a feeling there's some rounding going on with the measurement tool.


The "curves" look like abrupt changes because there is only a .5v difference between the high and low voltage during the entire 25hr period and the digital meter is only capable of .1v resolution, or 20% of the total change.

My flat data file (and therefore the graphs derived from the data) can't reflect the periods where the numbers on the voltage and amperage jumped between high and low before finally settling down. The transition from 3.1v to 3.2v wasn't an instantaneous jump - the 1 & 2 jumped back and forth for a good 10-20 seconds before finally settling on a 2. The abruptness in voltage changes is an artifact of representing digital measurements with analog visualization. The little blips at the transition points is an artifact of the line drawing algorithms in the charting utility.

When the voltage is plotted with the same scale as the amperage then it looks like a smooth line with a very slight incline. I blew up the scale of the voltage graph (perhaps wrongly) to exaggerate the changes so it was possible to correlate changes in voltage with changes in current.

Harmon


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## Harmon20 (Oct 5, 2017)

My car charger got here quicker than I expected. I'm only 10 cells in to charging the pack with individual cell chargers.

Opinions? Assemble the pack and let the on-board BMS do its thing or continue topping off the cells individually for the next month?

Also - anybody read Chinese?


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## rev0 (Oct 7, 2017)

Harmon20 said:


> My car charger got here quicker than I expected. I'm only 10 cells in to charging the pack with individual cell chargers.
> 
> Opinions? Assemble the pack and let the on-board BMS do its thing or continue topping off the cells individually for the next month?
> 
> Also - anybody read Chinese?


Might be risky depending on how different the state of charge/voltage is between cells is.

Here's the translations a Chinese to English dictionary provided (very handy website, lets you draw the characters: http://ce.linedict.com/#/cnen/home ):

1: Assuming this means wall power connected:









2: Assuming this means car connected:









3: Currently charging:









4: Error:


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## Harmon20 (Oct 5, 2017)

rev0 said:


> Here's the translations a Chinese to English dictionary provided (very handy website, lets you draw the characters: http://ce.linedict.com/#/cnen/home ):


Thank you. I've been looking for a good one since nciku.com shut down. The few I've found suuuuuuuuck. This one works as well as nciku did. Looks like it might even be the same engine under the hood.

Harmon


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## aidynphoenix (Nov 2, 2017)

watching with interest. since you are charging these batteries, you must of figured out what the max charge voltage is of each cell? i missed that part i guess.


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## Harmon20 (Oct 5, 2017)

The car specs say they're LFP batts and I have no reason to suspect otherwise. My understanding is that 3.6V is the standard. They will charge past that but it kills them. The chargers I bought do hold the voltage at 3.6v while the amperage drops off and they shut off at 3.6v @ 0A.


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## Harmon20 (Oct 5, 2017)

Ooooo, I'm excited. I just found a pdf from the Shanghai Science and Technology Information Institute in 2015 and an industry report from the same time that claims my donor car had a range of 160km. 

The Beetle has a curb weight of 1850lbs and swapping ICE & fuel tank for LFP batts and motor should be a wash, or pretty close to it. The JAC has a curb weight of 2600lbs. So I'm shedding about 800lbs or 30% as far as the JAC drive is concerned. I'm thinking 100mi range isn't out of the question, yes?

That's way better than I was expecting. I'm excited. Charging these cells is taking way too long. It's killing me. I'm ready to get this project under way.

Harmon


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## tylerwatts (Feb 9, 2012)

Sounds promising Harmon! I'm looking forward to your updates. Great work so far.

Cheers

Tyler


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## Harmon20 (Oct 5, 2017)

I keep going back and forth on the single speed vs shifting question for the Beetle. 

Part of me says I should take advantage of the fact I have multiple gears to select from to keep the motor where I want it for any given situation - high torque, high speed, low current, whatever.

Another part of me says I shouldn't try to re-invent the wheel and the JAC manufacturers have the motor mated to a single speed gearbox for a reason. Find the total ratio in the JAC and pin the Beetle trans in the closest gear.

The first part then points out that the reason is cost (money & weight) and simplicity. They'd go multi-speed if it weren't for the fact the cost:benefit analysis wasn't in favor of it and a typical user wouldn't be savvy enough to know what gear to select in an EV application. So since the Beetle already has multi-speed and I [sorta] know what to do with it then I should take advantage. 

Then the second part calls the first part an idiot, the permanent magnet synchronous motor has an inverter and control system that knows how to and can deliver what is asked of it with the throttle so quit thinking you know more than the engineers.

Anyone want to referee these two before it comes to fisticuffs?

Harmon


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## Kevin Sharpe (Jul 4, 2011)

Harmon20 said:


> Anyone want to referee these two before it comes to fisticuffs?


None of the OEM cars shift and I don't see the need for it in most conversions with current motors


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## Duncan (Dec 8, 2008)

Hi Harmon

My take on the single speed multi speed situation

I did the numbers and I realized that I could break traction in top gear - that means that going to a lower gear has no benefit


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## Harmon20 (Oct 5, 2017)

I think I'm going to go clutchless and just pin the trans in 2nd or 3rd. 

I just pulled the last cell off the charger this morning. The donor will be reassembled and tested this weekend. I'm excited!

Harmon


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## Harmon20 (Oct 5, 2017)

I finally got the batteries all topped off and I thought for sure I'd get the JAC pack put back together and tested this past long holiday weekend. I was too optimistic. I only got a couple hours a day to work on it and it is going together much slower than it came apart, much much slower than I'd anticipated. A lot of fiddly bits and wires to mess with and I find myself spending more time than I probably need to buffing conductive surfaces to get them nice and shiny. A patina on the copper tabs is probably the least of my worries in this pack but the little man inside me says I have to do it. My little man's an idiot.

Harmon


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## tylerwatts (Feb 9, 2012)

Don't skip these small steps now cause redoing the job will suck twice over and take longer to fix next time. Keep at it.

Cheers

Tyler


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## Harmon20 (Oct 5, 2017)

Well, a mixed bag today. Finally got a whole day with enough daylight and temps in the high 30s so I could get out and work on the JAC's battery pack. Winter sucks. Get up and go to work in the dark, come home at the end of the day in the dark.

I got it all back together, optimistically vacuumed all the glass off the dash in anticipation of massive winds coming over the front of the car as I blasted down the road, plopped a step stool down where the drivers seat was supposed to go, and floored it....nothing.

Meh. I knew it was too much to hope for but I played like I really thought it was going to happen in case it did. The climax to all the anticipation during the day as it came together would have been great. 

The charger I bought from Aliexpress didn't seem to even acknowledge the car at all.

Nothing really changed about the behavior of the car. I seemed like it wanted to work but thought the battery pack was dead. 

The accessory battery is only putting out 8v and the whole system died fairly quickly. Going to charge it up and see if it makes any difference. Probably not, but I'm going to hope anyway.

I said I'd write this whole thing off if it didn't drive and not sink any money into it, but I can't help it. It's trying so I don't want to give up yet. So the troubleshooting begins.

Harmon


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## GoElectric (Nov 15, 2015)

Hi. Lots of things could go wrong, but I would look for and check the inertia switch first - that will cut off power coming out of the pack.


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## Harmon20 (Oct 5, 2017)

GoElectric said:


> Hi. Lots of things could go wrong, but I would look for and check the inertia switch first - that will cut off power coming out of the pack.


I did not think of that. It has been wrecked so that would make sense even if the wreck doesn't look that bad. Thanks for idea.

Harmon


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