E-bike industry blames consumers for fires to undermine right to repair laws
So, here is my take. I&#x27;ve built my own battery pack, a pretty big one (170 cells of the largest capacity available), and it has served me well. But: I&#x27;m not your average DIYer and have spent a ton of time reading up on the do&#x27;s and don&#x27;ts of pack construction, made a smaller one first to experiment with and have researched pack safety until my eyes hurt.<p>My short take is that if you are someone who wants to revive their e-bike battery pack after it fails and who does not have extensive experience yet that it is going to be much cheaper and safer to just go out and buy a replacement pack from the same brand. I&#x27;ve seen multiple packs that had burned out wiring (usually: balancing wires, but also the main current carrying conductor), burned out BMS boards. Rarely did I open a pack that had been in service after developing a fault where the fault could not have potentially propagated. That it did not was in most cases sheer luck. Even for brand name gear!<p>It is super easy to mess up with these. Drop a pack, drop a sliver of wire or interconnect ribbon, misplace a tool and you have a thermal runaway on your hands which you will not be able to stop. Doing this in a facility that is not set up for it (say, your kitchen or living room, especially if it is in shared accommodation such as an apartment building) is <i>super</i> dangerous.<p>If you&#x27;re going to do this anyway, prepare to spend a grand or so on tools and a good month or so on creating a safe setup. After that you might as well go into business. I&#x27;m all for DIY stuff, but this isn&#x27;t one of those.<p>Finally: manufacturers <i>could</i> help with this: they could design their packs to be more reliable and easier to repair. They also could stop price-gouging the consumers on the packs, which is one of the reasons people want to repair them to begin with. But the packs are so chock full of DRM and other nonsense that repairing them properly is specialist work and they are so expensive that there will be a number of people that will try to repair a pack themselves anyway. Just disassembling a pack is not without risk.<p>If you go down this route feel free to drop me an email and I&#x27;ll send you a document that I have been working on for a long time to make working on these safer. Some ground rules:<p>- replace all cells at once<p>- weld your connections (NEVER solder them)<p>- use only the same cells<p>- use only cells that have all been charged to the same voltage<p>- make a thermal scan of the pack after the initial build during high speed charging and discharging to make sure you don&#x27;t have a cell in there that somehow stands out (it will surely fail)<p>- if you drop a pack or a cell consider it lost, even if it seems to still work<p>- only use A brand cells from a reputable vendor<p>- do not use recycled cells<p>- only use the original BMS<p>- Make sure none of your sense wires are crossed or loose enough that they can cross<p>- spend as much time on the mechanical part of your build as on the electrical part<p>hth