Bosch Powerpack 500 rebuild/replacement

[bombadero]

Hello, I recently noticed that the range on both of our e-bikes, a R&M Homage GT Nuvinci, and an HP Velotechnik Scorpion FS20 with Go SwissDrive system, have been greatly diminished and it looks like they are reaching end-of-life on both bikes. The R&M battery is at about 1/10th and the HPV about 1/6th. Both have dual batteries and I haven't checked either second battery yet, but expect to find much the same thing.

I've looked into battery rebuilds, and it looks pretty straightforward--and also about $700 cheaper. All that is really required is a soldering iron, which I have, a battery spot welder, new cells and optionally a multimeter. My questions in this post revolve around the Bosch Powerpack 500 specifically. I have seen successful rebuilds on YouTube of Bosch Classic+ batteries. I have also seen a teardown of a Powerpack 400 to repack it, but that video did not show the battery running successfully after a rebuild, just the teardown. A service local to my area, FTH Power, rebuilds e-bike batteries, but explicitly will not take Bosch or other proprietary batteries. They claim that when you replace the cells with an upgraded chemistry that you have to re-program the BMS firmware and re-flash the BMS. The Bosch Classic+ rebuild I saw didn't require that, and I'm not sure why that would be necessary unless the exact cell model were hard-coded into the firmware for some reason (and which would be very bad software engineering, but who knows). So my questions are:

• Has anyone here successfully rebuilt a Powerpack 400 or 500? What was your experience? Was it successful?
• The guy in the Classic+ video used a chisel to remove the nickel tabs. Is there a better way to do that?
• Is there any reason to keep to old tabs rather than convenience? Might it not be better to put in new nickel strips?
• If I stick with the same make of cells, Panasonic I believe, but higher capacity chemistry, like 35E, can I anticipate problems?

Extra credit for anyone who can answer the same questions about the Go SwissDrive battery for HPV. It could use it's own post, but it's so niche I doubt I will get any hits on it.

Alternatively, I'm willing to build my own entirely new batteries from scratch, but I don't know if the Go SwissDrive or Bosch computers and motors will play nice with a custom battery, even hooked up via their proprietary connectors. But if anyone has experience with that either, I'm very interested in your experience (especially if you succeeded ).

I've posted this on Endless Sphere as well.

 

[cheekee]

I have heard from a local guy to me who rebuilds e bike batteries that he wont touch bosch packs because the moment you open them and disconnect the BMS, it renders it uselsess and the battery cant be resurrected. Something to do with how bosch have programmed the BMS. I was speaking to him about rebuilding my giant dirt battery when the time comes.

 

[JRA]

Thank the state of CA and John Deere. Bosch is following that model it seems although there are no laws in effect regarding eBikes.

John Deere Just Swindled Farmers out of Their Right to Repair

The California Farm Bureau has given away the right of farmers to fix their equipment without going through a dealer.

www.wired.com

 

[rich c]

Thank the state of CA and John Deere. Bosch is following that model it seems although there are no laws in effect regarding eBikes.

John Deere Just Swindled Farmers out of Their Right to Repair

The California Farm Bureau has given away the right of farmers to fix their equipment without going through a dealer.

www.wired.com

Perfect, let's make this post about big brother! If you don't like Bosch, don't buy one. Same thing with John Deere, don't like the system, don't buy one. Lots of manufacturers of farm machinery out there. I didn't know we had farmers on this site!

I'm just fine with running Bosch and buying their batteries when I need to buy another one. The damned thing just provides everything I want in an eBike, so pleased to keep going. My oldest Bosch motor in a Haibike is a model year 2016. So battery is probably 5 years old. Even at $200 a year for a battery, over 3,000 miles a year, is just what it costs me for health and enjoyment. Hardly works out to more than a $1 a day for me.

 

[Herrie]

• Has anyone here successfully rebuilt a Powerpack 400 or 500? What was your experience? Was it successful? Yes quite some people on a German forum it seems. Also various companies do recelling. I just started with this process myself, so I don't have much experience yet in recelling itself. More opening and checking the broken battery packs I got. See if it's the cells or BMS. What happens often is that the cells voltage starts to drift (the pack is made up out of 40 - 18650 cells with 10s4p setup. Capacity and cell brand/type varies. I've seen LG mainly and some Samsung cells). Once the voltage difference between the 10 groups of cells exceed about 0,10 to 0,15V, the battery (BMS) might start to give 640 errors while using it for example (On the display). This can be solved by charging each of the 10 groups of cells to 4.2V (either individually or 42V at once @ 1A or 2A for example) and then you could use an active balancing board to equalize the voltages between the cell groups. Usually the drifting has a reason, but sometimes simply rebalancing the voltages solves the issue. Sometimes a couple of times (2-3) fully charging and discharging makes the cells "behave" better. I was able to revive some battery packs with low voltage (12V or even 1V for the whole pack) to work normal again after slowly charging the individual groups @ 500 mA @ 5V until about 2,5-3V and then let the Bosch pack and BMS charge it till full. If needed top it up a bit or drain each of the groups to balance. I don't have everything to do it automatically, so it's quite time consuming. If you have proper equipment it goes quicker.
• The guy in the Classic+ video used a chisel to remove the nickel tabs. Is there a better way to do that? Seems to be the best way to do it if you want to reuse them.
• Is there any reason to keep to old tabs rather than convenience? Might it not be better to put in new nickel strips? The Bosch tabs are pretty specific shape and decent quality. So reusing them has the preference.
• If I stick with the same make of cells, Panasonic I believe, but higher capacity chemistry, like 35E, can I anticipate problems? It should be fine from what I understood, as long as you use proper cells. Samsung 35E, Sanyo/Panasonic 3450 mAh would work too. The BMS might take a few cycles (3 or so) before it will recognize the new capacity (at least that's what I understood).

Extra credit for anyone who can answer the same questions about the Go SwissDrive battery for HPV. It could use it's own post, but it's so niche I doubt I will get any hits on it.

Alternatively, I'm willing to build my own entirely new batteries from scratch, but I don't know if the Go SwissDrive or Bosch computers and motors will play nice with a custom battery, even hooked up via their proprietary connectors. But if anyone has experience with that either, I'm very interested in your experience (especially if you succeeded ). This is a no go for Bosch really since you need a Bosch BMS, however you could create a custom higher capacity battery and use the Bosch BMS maybe.

I've posted this on Endless Sphere as well.