I currently use Eneloop batteries for my remotes and stuff. Are their any pros to nimh batteries now that we have lithiums that are 1.5mah? My Eneloops are only 1.2mah and aren’t strong enough for some things such as something with a little motor like a nose hair trimmer etc.
Which one lasts longer generally? So far I’ve had more lithium batteries that error and won’t charge over my Eneloops that have lasted many years.
If they’re good. Which ones are the best bang for the buck and reliable?
For raw cycle life and durability, 1900mAh Eneloops are basically for your best bet. They’re basically unkillable.
The main reason you’d want to use lithium-ion 14500 cells are for higher energy density(basically, they’re much lighter for the same capacity) or for higher power density.
Otherwise, just stick with Eneloops as volumetric energy density is actually rather similar.
Are you talking about batteries like Tenavolts, they’re a 3.7v lithium cell that is regulated down to a constant 1.5v. I have a couple of sets of them, they work better in high voltage devices ( our kitchen sink soap dispenser). It doesn’t really need the 1.5v,but the 1.2 reaches cutoff way before the batteries are empty.
Are you are talking about 3.7v batteries with step down converter to 1.5v? If so, their main advantage is higher voltage. Some devices just don’t work properly wiht 1.2v batteries. This might be the case for your trimmer. Speaking of power, 1.5v li-ions have high current cutoff at 2A (at least mine did). Eneloops can handle such discharge rate just fine, maybe even 3A is ok. So raw power output is probably higher for Eneloops. But there will be a voltage sag while li-ions will stay at1.5 volts up to cutoff. If it is not the voltage problem than I would go for Eneloops.
I think you meant V, not mah.
Anyway, it really depends on the application. In applications where higher voltage is preferred, the Li-Ion ones will be better. In applications where high current is needed, like high powered flashlights, NiMH will be better because those Li-Ion AA cells were not designed to handle very high current, as others posters already noted. Also, many of these Li-Ion AA cells, like the Tenavolts, require a proprietary charger.
Discharge capacity is similar to standard Eneloops, but Eneloops should survive a lot more discharge cycles.
Link to my review of Tenavolts: TENAVOLTS AA Lithium 1.5V rechargeable cells
The Tenavolts charge just fine in a standard Li-ion charger
According to HKJ, a Li-Ion charger will not charge them fully.
They need to get fed 5V straight from a usb source.
I got both kinds, the ones with and without micro-usb ports, and both need 5V.
Yeh, that’s the kind without the usb port.
The “charger” just passes the usb’s 5V to the cells’ end terminals, and has an LED to detect presence/charging.
Thanks 
I charge my tenavolts with a xtar vp2 all the time, set to 0.25A/ “3.8V” (4.35V charge current).
It would be interesting to measure the discharge capacity after charging with VP2 vs after charging with the factory charger.
I was wondering that myself
Not true. On…some……chargers, they may “appear” to. On others > nothing. The internal step circuitry interferes with the charging algorithm. You really do need to use the proprietary charger to charge them properly.
(Note - I have a dozen of them, and tried a myriad of alternative ways to charge them, to find out exactly that.)