Toyota is recycling old EV batteries to help power Mazda's production line

Neat idea to mix batteries of different age and chemistries. I've wondered why EVs couldn't do that too with some power electronics and SW. If an EV battery could have multiple such modules, it'd:

1) Make it easier to carry a cheaper lighter less-natural-resources-consuming battery most of the time. Go to some "gas station" to rent and add more modules when taking a road trip

2) Make it cheaper to replace the 1 module used a lot at its EOL, thereby making EVs last longer and be viable as cheap used cars even past 10 years like ICE cars are

3) Allow easier upgrades as chemistry improves: solid-state, sodium ion, etc.

Modules could be electrically tested for fit. I'd think the fit range would be quite wide (e.g. if one supported lower max discharge rates than another) given the headroom we have with EVs' power these days: they have far-more-than-needed power (which mostly comes for free with EV range).

The tradeoff is that they'd need to be built to be modular with some standardization on module dimensions (maybe we'll have "ZZ" size like we have AA, C, etc today), and would take a tad more volume in the vehicle (though the limiting factor is weight rather than volume). Easily worthwhile over the current model with a huge monolithic pack.

Re: 1, ignoring the complexities, is really interesting but depending on the effort to change our battery banks quickly makes renting a car more feasible.

And this highlights American traffic and sparseness.

- plug-in hybrids have 10-13 mile range which is great for running a few errands (this is only slightly more feasible than in a golf cart or ebikes) - also great for last mile connectivity for mass transit n users;

- the Nissan leaf 2012 had an 80 mile range - perfect for most daily commutes in a metro area

- modern electric vehicles have 200-300+ mile range, good for weekend getaways; esp with a charge at the destination

I’ve done the math a couple of times and IIRC if we can get the charge density per kilo to about twice what lithium ion can do, you hit a point where a deposit battery that’s around 20 kilos has enough range extension to start being worth doing. That’s the weight of a large bag of kitty litter or a commercial bag or rice. Put a good ergo handle on it and most people should be able to lift a few of them consecutively.

But until one unit is worth about 8 miles of extended range, there would be no point. 3@25 or 30 miles might make it worth the trouble for a road trip, or camping.

A great range extender weighing twenty kilos is available right now, a diesel generator.

It can also double as a air/water heater, emergency power for household or medical appliances, and emits about as much carbon in 30 years as it takes to manufacture a battery pack.

Honestly surprised Honda hasn’t designed a hybrid that’s more generator and less hybrid but I suspect that has to do with air and noise pollution loopholes for generators versus engines.