Yep working with big li-ion batteries is dangerous and should be done with proper equipment and safety measures, but claiming that nobody can do that but the producer is BS. They just make sure nothing else is compatible so you have no alternatives. Same with electric tools - is every lawn mower so unique that it can't be powered with another brand's battery? It could, but to prevent that producers add proprietary authentication and such. They even make new generation of tools incompatible with previous gen batteries, just to be sure you're not accidentally reusing anything.

Would you say that people categorically shouldn't be allowed to tinker with their cars, lawnmowers or other gasoline powered devices?

Gasoline is WAY more energy dense, WAY more likely to cause a fire, WAY more likely to spread a fire by virtue of being a liquid, needs specialized firefighting training and equipment, and causes cancer even when it isn't on fire.

Most people don't particularly care if their neighbor has 165 kilowatts of gasoline sitting around (5 gallons). I don't know if that is because we have been conditioned to ignore the dangers of gasoline and gasoline powered devices, or if we are overreacting to the dangers of Lithium batteries. Just for reference most electric cars do not have 165 killowatts of storage.

The reality is that battery packs aren't often "repaired". Good practice dictates that you really want all of your cells to match in terms of age and usage. Cells normally need to be welded together by a single purpose battery welder, so if you are hand-building a battery pack you have invested significantly into the equipment and know-how. Home repairs of "batteries" likely are just dismantling the casing, removing the packed cells, and putting in a new cell pack.

I think you misread my comment!

I think I understood it.

My point was that we regularly undertake things that are regularly just as, if not more, dangerous than tinkering with batteries. This fear-mongering from manufacturers is silliness designed to let them get away with consumer unfriendly designs and regulation under the guise of safety.

Repairing a bike is something that I learned in middle school, and working with batteries is something that I would trust a high schooler with a few hours of training with.

In your clarification, I still don't see anything I disagreed with.

I have an E-bike, I'd repair everything but the battery. The battery I have is expensive at about $1K. So I can see why the 'working person' may want to have a crack at repairs on their own, but it's risky.

With bikes, there's a tradeoff with weight. If the batteries were repairable. I could see them getting heavier to make them more friendly with clip in joints and lots of inbuilt safety. Rather than the sealed for life style that they currently exist in.

Anyway, I'm happy to send my bike to a mechanic. It;s money in the local economy. Though I did get a car service that was cheaper than my last bike service. Which was kinda wild in retrospect.

IMO batteries need to be standardized, documented, training and parts available and certification programs for repair. I should be able to take my battery to a certified technician/shop and have it serviced (bad cells replaced, battery management board replaced) without having to worry about it.

That's an excellent plan.