4 ms·
> NiMH was far superior to lead acid, superior to nicad, and much cheaper than lithium ion. Except on a couple accounts - Memory and Lifetime. NiMH batteries
by Aloha 3y ago
> NiMH was far superior to lead acid, superior to nicad, and much cheaper than lithium ion.
Except on a couple accounts - Memory and Lifetime.
NiMH batteries have almost as bad as a memory effect as NiCD, and have a low lifetime cycle count compared to lead acid. I dont think you could put NiMH batteries in a production car, at any point, without designing the battery pack to be cheaply and easily replaced. NiMH batteries are far more of a consumable than even Lithium batteries are. There are also real limits on how much current an NiMH battery can deliver in a given period of time.
NiCD batteries because of the memory effect an inability to deal well with high current applications, made them unsuitable for a mass market electric car.
- cyberax 3y ago> low lifetime cycle count Top of the line NiMh chemistries had lifetime cycle count better than many Li-Ion batteries, like 10% degradation after 2000 cycles. They also don't have the memory effect, but can exhibit a somewhat similar but fully reversible effect. Really, the energy density was the main killer.
- kalleboo 3y agoNiMH works fine in cars - Toyota has been using NiMH in many many generations of their hybrid cars like the Prius and they have held up very well. The problem is just the energy density once you need to maximize range.
- Aloha 3y agoI stand corrected, thank you!
- kalleboo 3y agoIt's really counter-intuitive to those of us who grew up with the NiMH->Li-ion transition in consumer electronics! When I learned that Toyota used NiMH in the Prius it was kind of a "mind blown" moment.
- Aloha 3y agoI could swear that the Prius was Lead Acid AGM batteries. But like, most of the issues I had with NiMH was because the devices that had the batteries in them had no charge controllers, so all the effects I spoke about were true for those - NiMH with a battery controller, and without might as well be completely different beasts.
- kalleboo 3y agoYeah proper battery controllers, and modern chemistries (see eneloops on the consumer end - they're also a bit of a game changer)
- masklinn 3y ago> I dont think you could put NiMH batteries in a production car, at any point, without designing the battery pack to be cheaply and easily replaced. RAV4 EVs have gotten 150k miles out of their original battery pack.