I looked it up and the only direct 1.5V compatible AAA battery tech I found (source for the curious) seems to use lithium iron disulfide and are not rechargeable.
The rechargeables I found in AA/AAA format use lithium iron phosphate which outputs 3.2V so they must have internal circuitry (and hence losses) to be drop-in compatible with other AA/AAA (batteries in a standard format with non-standard voltages are a great way to get non-expert users to blow up their electronics devices). The internal electronics probably explains why they’re so much more expensive than other rechargeables and, looking around, their capacity doesn’t seem to be much more than NiMh (about 10-20% more).
Dudewitbow@lemmy.zip 1 year ago
The advantage liion has with the AA size is that it maintains its voltage better than nimh as nimh can only supply 1.2V and some applications that use AA batteries start to not work when nimh have a lower charge because of the voltage drop being smaller than the required voltage.
The main con with liion is its a fire hazard and is fairly toxic
Showroom7561@lemmy.ca 1 year ago
Yes, and yes.
I do see that LiFePO4 AA batteries seem to be available, which could mitigate the safety concerns, but I still don’t think it would be as safe as alkaline or NiMh.
You also need to consider that lithium batteries have a significantly longer shelf life vs Alkaline and can be safely operated well below freezing. They also weigh less, if that’s a concern.
Pros and cons to both, but at least standard battery form factors have options! When a company decides to use some proprietary, hardwired battery pack in their device, they’ve basically given you a big FU!