E Golf Battery pack Topic is solved

[Alibro]

**********SAFETY WARNING**********

Edit:
I'm adding this here so hopefully you will see it before attempting to open one of these packs.

I don't know if all eCar packs are the same but this pack has no physical safety disconnect to cut the pack in half, it will be at full voltage until you break it down.
It also means it is at full voltage while you are cutting the top off which is not easy and if you do it wrong you WILL cut into the battery modules!! I was lucky as before I figured out the best method I slightly cut into a module with my chisel but caused no harm.

The top of the pack is some kind of fibre glass covered in metal foil. It is so well glued down you will not be able to prize it off so will have to cut the top off.
To do this you MUST cut straight down at the corner of the bottom flange. Cutting flat in towards the pack will probably result in damaged modules and possible fire as unlike Leaf packs the modules have no protection.
I used a 1" wood chisel to cut the top off but I think one of those vibrating multitools would do it much cleaner and easier.
Even cutting straight down there are a couple of places where you could cut through BMS wiring so DO NOT use a Dremel or grinder to cut the top off.
I'll take some photos later and add them to this post.



Hi guys
I'm considering purchasing a battery pack from a 2020 e-Golf so asked some questions in the ebay thread and Bigpie kindly answered me so I thought it better to continue the conversation here.
This is the pack I'm talking about. https://www.evbreakers.com/product-page ... hv-battery
It's a 35.8kWh pack from a car with only 165 miles so basically brand new.
The cells are a mix of 15.2V https://www.ebay.co.uk/itm/VW-e-Golf-15 ... SwDgtfqRK5
and 7.6V https://www.ebay.co.uk/itm/VW-e-Golf-Mo ... Swn9Jf7dRx

If I have this right Bigpie says I can currently use the CAN connections in each module to monitor voltage and temperature but for the moment not balancing. This means I have to either fix the balancing issue or use a third party BMS.

If anyone else knows more about these battery packs then please share.

[Alibro]

So I was lying in bed mulling over the options (like you do) and it occurred to me that charging with my Nissan Leaf charger would be an issue.
Yeah big surprise!
The Nissan Leaf battery pack is 96S and as far as I can tell the e-Golf is 88S so either I need to use the Golf charger or buy two more 4S modules.
I had a quick look on ebay and chargers for e-Golf's are available also I could probably negotiate a charger from the car that's being dismantled but can we control them yet?
Modules similar to the ones in the pack I'm looking at are over £500 each, so although it would increase the range I don't fancy spending over £1k just to experiment with the Leaf charger.

So having had a look at the chargers mentioned in the Wiki it seems Tesla Model S and Mitsubishi Outlander chargers have been cracked but Tesla chargers are expensive so will the Outlander charger work with an 88S pack?

[m.art.y]

Are there any chargers available for 88S packs from other makes/models of car that have already been cracked?

Yes, you just need a charger where you can control/set the desired target voltage. You can use tesla, volvo v60, brusa, volt and maybe some others. These have been documented.

[Alibro]

Are there any chargers available for 88S packs from other makes/models of car that have already been cracked?

Yes, you just need a charger where you can control/set the desired target voltage. You can use tesla, volvo v60, brusa, volt and maybe some others. These have been documented.

Thanks for the reply. I didn't expect anyone else to be daft enough to be online at this time and had already edited my question.
I'll look into the chargers you mention.

[m.art.y]

Thanks for the reply. I didn't expect anyone else to be daft enough to be online at this time and had already edited my question.
I'll look into the chargers you mention.

Was it you who was thinking to also use leaf bms together with the leaf charger? If you are unwilling to add more modules then that's probably not an option.

Bear in mind that tesla gen 2 charger is 10 kw, outlander charger is ~3.3 kw. To get to 10 kw you will need to add 3x outlander chargers so 3x the price. It depends on what charging capacity you want. Outlander charger will work with your setup no problem but it's voltage control is a bit more tricky - you cannot set target voltage on it it will just keep charging. What you need to do is watch for it's can messages (it constantly reports at what voltage it is currently charging) and when it gets to your target voltage you set your arduino to drop the charge current and then eventually set the charge current to 0. Read the outlander charger thread. Other chargers are a bit more friendly as they have constant voltage mode and you can set your desired voltage directly. Good option is volvo v60 charger apparently due to ease of control and compact size. Also have in mind that you can stack 3.3 kw chargers in parallel to get to desired charging capacity. It depends on which option is cheaper and how much space you have. Also regarding tesla charger you have to purchase a control board and optionally software which increases the price. You can hunt for outlander/volvo chargers you might be lucky and find a good deal. When I was looking for one prices between sellers vary wildly I was qouted from 280 to 600 for the same charger.

Forgot to mention that outlander charger has also a dc/dc converter inside it. So you won't need to buy a separate one.

[Alibro]

Thanks for the reply. I didn't expect anyone else to be daft enough to be online at this time and had already edited my question.
I'll look into the chargers you mention.

Was it you who was thinking to also use leaf bms together with the leaf charger? If you are unwilling to add more modules then that's probably not an option.

Yes, I bought a Leaf that had the only HV battery removed but everything else was there. I stripped the Leaf before selling on the body so I have pretty much a complete Leaf electronics. Since then I also acquired a Leaf BMS so my original plan was to buy a Leaf pack and I would then have everything required to get it going but the 35kWh E-Golf pack is very tempting if I can find a way to charge it.
The Outlander charger sounds like it could work especially if it has the DC to DC built in.

[m.art.y]

Yes, I bought a Leaf that had the only HV battery removed but everything else was there. I stripped the Leaf before selling on the body so I have pretty much a complete Leaf electronics. Since then I also acquired a Leaf BMS so my original plan was to buy a Leaf pack and I would then have everything required to get it going but the 35kWh E-Golf pack is very tempting if I can find a way to charge it.
The Outlander charger sounds like it could work especially if it has the DC to DC built in.

Ok, I get it. You have to carefully check your options. Lower pack voltage might affect top speed to some degree. Having a complete leaf system might be easier to get all systems working - bms, charging, chademo. If you go for a custom built system you will have to figure out every aspect but that might not be such a bad thing in the end - that has been documented and is doable.

[johu]

A charger that will charge 96S will also charge 88S. Cutoff voltage is certainly useful but not essential. Normally you receive a current limit from the BMS and forward that to the charger. Just make sure the charger cuts out when not receiving from the BMS.

[Alibro]

Ok, I get it. You have to carefully check your options. Lower pack voltage might affect top speed to some degree. Having a complete leaf system might be easier to get all systems working - bms, charging, chademo. If you go for a custom built system you will have to figure out every aspect but that might not be such a bad thing in the end - that has been documented and is doable.

Lower speed was also a factor I was considering but a virtually brand new 35kWh pack for £4k less than 30 miles from home is hard to ignore.
Top speed was never a priority and adding a few more cells down the line would fix that anyway.
I understand the advantages of having a custom system and ultimately may end up that way but my 1st priority is to get the damn thing working so keeping things as simple as possible should hopefully help to get there a little quicker.
Keeping things as simple as possible is always best for me.

A charger that will charge 96S will also charge 88S. Cutoff voltage is certainly useful but not essential. Normally you receive a current limit from the BMS and forward that to the charger. Just make sure the charger cuts out when not receiving from the BMS.

Thanks Johu,
If that is the case and I decided to use the Nissan charger and BMS then keeping the BMS happy would be the trick.
Could I have eight standard 18650 cells connected to the BMS but not the output of the pack? If they were charged to the maximum I intend for the rest of the pack then when the pack is charged the BMS would see 96 cells.
I guess this could only work if the BMS only balances at full charge.
Anyone know does the Nissan Leaf BMS try to keep the pack balanced at all times or just when fully charged?

[m.art.y]

Could I have eight standard 18650 cells connected to the BMS but not the output of the pack? If they were charged to the maximum I intend for the rest of the pack then when the pack is charged the BMS would see 96 cells.
I guess this could only work if the BMS only balances at full charge.
Anyone know does the Nissan Leaf BMS try to keep the pack balanced at all times or just when fully charged?

Sometimes you just have to go for what is available. Battery is the most important part of the conversion, if you get a good deal on it then go for it. Much easier to compromise on everything else.

Your idea with 18650 cells to fool the BMS is hardly realistic. You would have to cycle those cells exactly as the main battery cells. Once BMS detects a significant difference in voltages between cells it will shut you down. If it would even work at all because I suspect leaf BMS takes into account internal resistance of cells.
With this battery your only options are simp bms or any custom bms. And everything else custom. Which will give you freedom to use what is available.

[Alibro]

Sometimes you just have to go for what is available. Battery is the most important part of the conversion, if you get a good deal on it then go for it. Much easier to compromise on everything else.

Your idea with 18650 cells to fool the BMS is hardly realistic. You would have to cycle those cells exactly as the main battery cells. Once BMS detects a significant difference in voltages between cells it will shut you down. If it would even work at all because I suspect leaf BMS takes into account internal resistance of cells.
With this battery your only options are simp bms or any custom bms. And everything else custom. Which will give you freedom to use what is available.

LOL, I thought it was a dumb idea but worth a try.

If the pack I'm looking at is as new as claimed then the cell modules will all be well balanced anyway. I know a BMS will be essential over time but I also know many people in the ebike world don't like or trust them. Some even refuse to have a BMS at all and report no significant voltage differences in their packs after many charge/discharge cycles. If I can use SimpBMS to monitor the pack then I'd be happy to go ahead without a working BMS in the short term anyway and work on getting a 3rd party BMS or maybe even the VW BMS working.

I think I'll give the guy a call and see what happens.
Thanks again for all your input guys. It's very much appreciated.

[m.art.y]

If the pack I'm looking at is as new as claimed then the cell modules will all be well balanced anyway. I know a BMS will be essential over time but I also know many people in the ebike world don't like or trust them. Some even refuse to have a BMS at all and report no significant voltage differences in their packs after many charge/discharge cycles. If I can use SimpBMS to monitor the pack then I'd be happy to go ahead without a working BMS in the short term anyway and work on getting a 3rd party BMS or maybe even the VW BMS working.

I think I'll give the guy a call and see what happens.
Thanks again for all your input guys. It's very much appreciated.

Yes exactly! Most importantly you need a way to monitor cell voltages to be able to judge the condition of the pack and also when you charge/discharge your bms must stop charge/discharge if one cell goes outside the allowed voltage range. If battery pack is good it shouldn't drift too much out of balance for a number of years.
Good luck

[Alibro]

Sometimes you just have to go for what is available. Battery is the most important part of the conversion, if you get a good deal on it then go for it. Much easier to compromise on everything else..

OK so the deal wasn't quite as good as hoped as VAT was involved but I made the purchase and will be collecting the E-Golf pack on Saturday. It is still around £2.5k less than slevb.com are asking for the same pack and I got a charging lead thrown in.
The guys in EV Breakers had already had a go at opening it but it's really well glued together and they hadn't quite got it open yet so it will be fun for me but I'll update further when I get it home.
Turns out they know Damien well and have supplied him a few times so I'm in good company.

[Stephen Darbey]

Hi Ali
Best of luck with new purchase. Saw the pack advertised but nowhere near ready for it. Congrats on purchase and best of luck. Will be watching carefully.

Regards
Stephen

[JaniK]

Hi Alibro,

Great find!

I was just watching your Leaf motor turning videos the other day and now stumbled on this thread.

I have a 2019 35,8kWh E-golf pack (in parts) and SimpBMS.
CAN monitoring is working.

I also have an outlander charger to use with this combo.

So basicly going allmost identical battery system, except different vehicle.

The VW CAN wiring was I bit tricky, I have traced all the CAN wires with multimeter. But when you open the pack, could you verify the connections. Since i got my modules delivered in parts.

I can send you the schematics i made later.

If you go with SimpBMS, there is some quirks in wiring. Ask me later and i can check how i got it working.

-Jani

[Alibro]

Hi Ali
Best of luck with new purchase. Saw the pack advertised but nowhere near ready for it. Congrats on purchase and best of luck. Will be watching carefully.

Regards
Stephen

Thanks Stephen, really appreciate your kind words.

The guys at EV breakers seem to have new stock coming in fairly regularly so when you're ready they will have something for you. It seems that much of the stock they get is new or nearly new, the Golf my pack came from looks like it fell of a transporter.

Hi Alibro,

Great find!

I was just watching your Leaf motor turning videos the other day and now stumbled on this thread.

I have a 2019 35,8kWh E-golf pack (in parts) and SimpBMS.
CAN monitoring is working.

I also have an outlander charger to use with this combo.

So basically going almost identical battery system, except different vehicle.

The VW CAN wiring was I bit tricky, I have traced all the CAN wires with multimeter. But when you open the pack, could you verify the connections. Since i got my modules delivered in parts.

I can send you the schematics i made later.

If you go with SimpBMS, there is some quirks in wiring. Ask me later and i can check how i got it working.

-Jani

That's great to hear Jani, when I get the box opened I'll report back and will ensure to trace all wiring.
I'm hoping to pick it up on Saturday but it may be a little while before I do much with it as I want to get the motor mount completed. I need to get the car moveable again to get it out of the way before I can work on the pack.

[Alibro]

I picked up the pack today in my van and got it home safely.
I'm not sure how heavy it is but my engine hoist struggled to lift it even with the boom at 1.5 tonnes but I was able to lift it just high enough to let my wife drive the van forward leaving the pack hanging. The hoist was really cheap so it was probably the problem but I suspect the pack is well over 500kg.
Here is a pic of where I have it now until I get the motor mount fabricated and the car moved. Don't worry I have it well covered with plastic sheets.

Also on the subject of charging/BMS the guy who sold this pack said he has another e-Golf coming in and he plans to split the pack in this one so I may be able to buy two more 4S modules. If they are not too expensive it may allow me to use the Leaf charger and BMS but I'll not be certain if I can do that until I get the pack open.

[JaniK]

According to vw the 24,2kWh pack is 318kg.

And it is the same size but different cells,
So i guess 3xxkg for the OG pack.

The modules in 35,8kWh pack themselves:
Larger module ~11,4kg / 35,5x15x11cm
Smaller module ~6,2kg / 19,5x15x11cm
-tape measurement

I just weighted them on trusty HelloKitty bathroom scale.
So +/- some hundred grams might be in order

Yes it's a bathroom scale reading of a 2019 e-golf 4S3P module.

You will find inside a mix of:
17x larger modules and 10x smaller.

There are 2 types of the larger module,
8 has a BMS slave inside and 9 are controlled by the slave module with interconnect cable, the interconnect does not include the connection between modules, so a HV connection is needed to make the slave see all the modules connected to the slave.

I tried to get it working with only BMS cables many many times with errors, then added HV between modules and pling it just works. The VW bms slave also need to see the "end of the loop" or it doesn't like work properly. So only the slave and it doesn't like to work.

[Alibro]

According to vw the 24,2kWh pack is 318kg.

And it is the same size but different cells,
So i guess 3xxkg for the OG pack.

The modules in 35,8kWh pack themselves:
Larger module ~11,4kg / 35,5x15x11cm
Smaller module ~6,2kg / 19,5x15x11cm
-tape measurement

I just weighted them on trusty HelloKitty bathroom scale.
So +/- some hundred grams might be in order
DSC_1041.JPG

You will find inside a mix of:
17x larger modules and 10x smaller.

There are 2 types of the larger module,
8 has a BMS slave inside and 9 are controlled by the slave module with interconnect cable, the interconnect does not include the connection between modules, so a HV connection is needed to make the slave see all the modules connected to the slave.

I tried to get it working with only BMS cables many many times with errors, then added HV between modules and pling it just works. The VW bms slave also need to see the "end of the loop" or it doesn't like work properly. So only the slave and it doesn't like to work.

When you say "It just works" do you mean the BMS is balancing the pack all the time as soon as the cells are connected. If so I won't need to use the Leaf BMS at all.
Does it balance the pack at all times or just when fully charged?

[JaniK]

According to Tom, the SimpBMS doesn't handle balancing of vw modules. Sorry I was bit vague with "it just works", i ment it works as in the SimpBMS documentation.

Example you get:
Individual cell voltages
Some Module temperature readings.
Pack total voltage
SOC

Balance is still a mystery. Maybe it could be possible for you to discharge a single module/cell to lower voltage than others and power up the full pack to see what CAN messages appear and does the VW BMS start to balance the cell. But I have like next to no idea how to "start" the pack. It would be awesome to get the balance working.

[Alibro]

LOL, I see what you mean now.
I heard the Leaf BMS and and DC to DC will start to work as soon as it is all connected so was hoping the Golf would be the same.
I'll try to take some voltages from the Golf pack when I get it open.

[rstevens81]

I wouldn't get too hung up on balancing just yet ...

Arber333 made a good point in the thread below:

Regarding battery drift i think if you use them from 4.0V to 3.0V per cell you will not have much drift. I have noticed a certain drift between cells gets established probably because of diferent conditions inside battery boxes. Some of them may be in the cented where they are warmer and some are at the ends... Which affects the voltage state, but not SOC! I repeatedly saw cells diverge some and i left the cells for some time without heavy maintenance. And it seems they went into their own SOV (state of voltage ) without affecting SOC. And since i didnt discharge them too much everything stayed the same...

viewtopic.php?f=9&t=1402&p=23900&hilit=4v+cell#p23900

I'm using 2 Passat packs and am intending to normall set the charge voltage to 4v/cell and only go upto 4.1 mayber 4.15 when I'm going in a long journey i.e trip to beach etc.
Basically I'm when project is built (has gone on hold as my wife want a bigger house ), I'm going to be taking the monitor approach using a modified version of simp to keep an eye and see if it's something to actually worry about wort case I replace the BMS from something else (leaf, open inverter etc).

Edit... Ps love the bathroom scale, my daughter would love that

[JaniK]

Those hybrid VW packs seem like a good choice too.
Very many projects seem to be delayed because time is spent elsewhere. But that is life. I hope to get my project on the road this summer. But i have had many setbacks on the car itself, without any EV parts yet. So maybe late summer. Hope to get to first test drives early summer though. But my project is like umm. Taken off the road 1967...

Rstevens81: Glad you liked my scale

[rstevens81]

It actually hasn't really stalled, I have to get the car back together in ice form so it can drive so it feels like it, I even removed the fuel tank! but I've done alot of repairs/restoration, spent some of Sunday with the battery module simulator v0.1 aka cardboard box (it was made from the box that more cardboard boxes came in) . So I can start designing and building battery boxes soon, a gearbox is peanuts (found a listing for £35 today) so I can start working on the motor assembly soon. Have been busy with talking to the BMS with a teensey 3.6. so I have been moving forward just feels like I have to make a giant leap backwards first!

Edit fyi, there is a VW section on the wiki that myself and bigpie have been sporadically adding to, if you can add a e golf section and add things as you go I'm sure the the ev converters of the future would buy you a beer .

[JaniK]

Will be adding stuff on the way, I am fixing the car and gathering conversion parts. Once I have the EV side sorted and the car body ready to accept the parts, I will start making more fuzz about it.

Alibro, the 16pin BMS connector from original harness, see part number, and start of how I got it connected and talking to simpbms.

What a mess.