Bosch powertube repair

[paul-home]

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.

 

[wheeliepete]

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.

 

[obcd]

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.

 

[Pajda]

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.

 

[hemo]

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]

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

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.

 

[paul-home]

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!

 

[Batteryrepair]

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.

Not true. If the bms doesn't work, you have a bad bms. The powertube bms's can be swapped. I've done over 30.

 

[marka-ee]

Not true. If the bms doesn't work, you have a bad bms. The powertube bms's can be swapped. I've done over 30.

Is this true of the older Bosch power packs as well? In other words, can the BMS be removed and powered down completely during a cell change?

 

[Batteryrepair]

Is this true of the older Bosch power packs as well? In other words, can the BMS be removed and powered down completely during a cell change?

Oh yep they can be removed and powered down, no issue. What sometimes happens is that the BMS has a defect in the 5V converter and then discharges all the cells, while also bricking the BMS. I guess thats why that myth exists: they see an empty pack and a BMS thats not working. But I assure you, if the BMS was working when you removed it, it will work when you power it up.

 

[marka-ee]

Okay, great. That's good to know. Bosch is not as evil as I thought.

 

[Batteryrepair]

Okay, great. That's good to know. Bosch is not as evil as I thought.

They still don't supply any parts for the batteries. Not even a simple connector or plastic case. Or gears for the motor.

 

[Chalo]

Okay, great. That's good to know. Bosch is not as evil as I thought.

They're evil; do not doubt. They booby trap their new generation of e-bike batteries so you can't reassemble them after opening them for any reason.

Bosch equipped e-bikes are not for your benefit-- they are for Bosch's benefit. Don't forget you are there to serve them and not the other way around.

I hope that we get some good aftermarket hacking action for these things, or else they're all landfill on a short time scale.

 

[marka-ee]

My Bosch bike is what I call my exercise bike because I have to pedal it. It is a pleasure to ride and with its Gates belt and Nuvinci continuous transmission with automatic cadence holding feature it's quite fun to ride I must admit. The frame is German not Chinese and it's really one of the most solid bikes I've ever ridden. However now it started doing this thing where the power is surging with a period of about three or four seconds between lots of power and not so much power. I'm not sure what it is because the battery still shows close to full charge. The problem with these bikes is they're very proprietary and therefore hard to debug.