VW Hybrid Battery Packs

Information on reusing VW Golf/Passat GTE hybrid battery Packs.

Specification Overview

Passat GTE

The 9.9 KWH Passat GTE battery pack contains 96S 28AH Samsung cells arranged in to 4 modules of 24S with a liquid cooled heatsink down the middle.

Golf GTE

The Golf GTE battery pack has a plastic top cover, containing 8.7 KWH Panasonic cells arranged in to 4 modules of 24S with a liquid cooled heatsink down the middle.

Disassembly

I Can Not understate the importance of Insulation when dealing With High Voltages, Both of your tools and yourself of course! Also ensuring that we do everything to prevent a Shor Circuit.

All Metal tools were covered in Tape And/Or Heat Shrink so that in the event of a drop there would not be a dangerous short circuit, and also as an added layer of insulation from the battery to myself!

I only ever toughed the HV contacts when I absolutely had to, no point taking chances!

Useful/Tools used:

1. Torx & Socket Drive Set (insulated with shrink wrap/tape)
2. Electric Screwdriver
3. Magnet on a stick (Covered in tape of course)
4. Insulation Tape & Duct Tape
5. Gloves … I used nitrile gloves, Electrician’s gloves & some garden gloves so I didn’t tear the electrical gloves.
6. Electrical screwdrivers & a normal screwdrivers covered in insulation tape.
7. Voltmeter
8. Insulated shoes
9. Nylon straps the battery came tied to the pallet.
10. Emergency help on hand in case of electrocution (including gloves for them & I attached one of the nylon straps to myself so I could be pulled away)
11. Work in the dry obviously

After Undoing all of the torx bolt on the top the cover can be removed … look at those precision straps to hold the modules down.

At this point after prodding about underneath the foam and looking down the sides I need access to the bottom to unbolt the modules, find that un-loved screwdriver (covered in paint in my case on top of my daughter’s rabbit hutch) and use gentle persuasion to remove the rubber plugs to get access to the torx bolts and remove them. Be very careful this thing is damn heavy you don’t wan this to land on your toes or any part of your body

Now back to the top side … remove all the foam, disconnect all of the cables you can (I could not remove the module bms plugs). Happily my module sat at 355 volts (88.8v per module) so not too low at about 3.7v per cell!

I then started tackling all of the bolts holding down the modules in the middle, however then came the ones that were under the Contactor box.

The scary bit where I disconnected the HV connections from the Contactor box thing, immediately covering with insulation tape, first negative, positive, then I tackled the mid pack connection (not shown in this photo). Then I removed all of the connections from the contactor box to allow it the removed to allow access to the torx bolts obstructed by it.

Now back to the top side … remove all the foam, disconnect all of the cables you can (I could not remove the module bms plugs). Happily my module sat at 355 volts (88.8v per module) so not too low at about 3.7v per cell!

I then started tackling all of the bolts holding down the modules in the middle, however then came the ones that were under the Contactor box.

The scary bit where I disconnected the HV connections from the Contactor box thing, immediately covering with insulation tape, first negative, positive, then I tackled the mid pack connection (not shown in this photo). Then I removed all of the connections from the contactor box to allow it the removed to allow access to the torx bolts obstructed by it.

BMS

The BMS slaves on the modules can be re-used using SimpBMS running on a Teensy Microcontroller.

https://github.com/Tom-evnut/SimpBMS

https://github.com/Tom-evnut/VW-bms

Contactors/Pre Charge

Golf GTE

The control box contains a

• PEC 250A 450VDC fuse
• 2 x Panasonic AEV14012 M28 contactors https://docs.rs-online.com/6251/0900766b80e1fbed.pdf, yazaki 7283-1020 is the connector
• pre-charge relay and resistor,
• Current shunt.

Golf GTE Fuse	Main Control Box	Pre-charge relay
Contactor

Reusing with Open Inverter controlling the contactors and relay directly should be as simple as supplying 12v and switching the ground as required.