Bosch powertube repair

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paul-home

100 mW

Joined

Aug 2, 2008

Messages

37

• Feb 17, 2020

• #1

Has anyone on here attempted to repair a Bosch Powertube battery? I picked up 4 500wh powertubes on ebay for £25 each.
All the cells are LG 3500mah. They are all discharged to just a few Millivolts. The design of the pack makes we wonder if its possible to repair. The BMS is mounted on a flexible PCB which is spot welded down the length of the pack.

 

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wheeliepete

1 mW

Joined

Jul 11, 2016

Messages

17

Location

Devon/Dorset UK

• Feb 17, 2020

• #2

If you are in the UK, contact Jimmy at ebikebatteries.co.uk, he may be able to re-cell them for you, although if there is zero voltage in the pack, the BMS is likely to be toast.

 

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obcd

100 W

Joined

Jul 16, 2019

Messages

170

• Feb 17, 2020

• #3

Bosch doesn't like it if you mess with their batteries. If you disconnect the cells from the bms or even disconnect one of the balance wires, the bms "shuts off" and refuses to restart afterwards. It needs some factory hocus pocus to come back to live.
I have no idea if your packs are like that, but modern bosch ones are.

 

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Pajda

10 kW

Joined

Jan 24, 2016

Messages

572

Location

Czech Republic

• Feb 17, 2020

• #4

Can you add some photos of disassembled pack? But I agree with others, when the Bosch BMS is disconnected from the battery, it locked itself and it is no longer usable.

 

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hemo

100 W

Joined

Mar 30, 2016

Messages

241

Location

England, GB ( UK).

• Feb 17, 2020

• #5

Jimmy in London at ebikebatteries.co.uk I believe parallels the BMS to another source (likey the new cell pack) once this is done the old cells can be disconnected. Though if a cell group is toast the BMS may well be bricked.
He recelled my brothers Bosch pack but that was a Gen 1 or 2 pack.

 

PaulD

1 kW

Joined

Aug 28, 2008

Messages

361

Location

Ashland, OR, USA

• Feb 17, 2020

• #6

paul-home said:

All the cells are LG 3500mah. They are all discharged to just a few Millivolts.

Click to expand...

It's not recommended to revive cells that have been discharged below about 1V. At low voltage copper tends to dissolve into the electrolyte and gets re-deposited onto the electrode during charging, and cause shorts. Many BMS are designed to prevent charging if a cell ever drops this low.

 

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paul-home

100 mW

Joined

Aug 2, 2008

Messages

37

• Mar 22, 2020

• #7

Sadly its true. I have spent a lot of time rebuilding the pack, the BMS is somehow locked out.
If anyone figures out how to re-initialise the BMS, please let me know!