Those high-current lithium AA and AAA cells

[Mark Hammer]

Ali Express keeps stuffing my mailbox with ads for various high-current rechargeable lithium batteries.  The idea of 6800mAH from an AAA, making an 8-pack a small powerful source of clean  power, is quite seductive.

In past (and I mean past), several of us here had recommended to people plagued by noisy supplies that a 6-pack or 8-pack of C or D cells could provide a valid alternative.  But AAAs are even more compact.  Not quite as cheap as a made-in-China (Caline, Amoon, Donner, et al) power brick, but it reduces AC outlet needs by one.

Any caveats to note?

[R.G.]

The biggest caveat is that 6.8 A-Hr in a AAA is likely to be a tad exaggerated. There is a history of ebay and aliexpress lithium batteries being over-advertised.

It is great if it's true, but verify.

A point to consider is that the electrochemical nature of lithium ion cells is a cell voltage of 3.6V nominal. Any lithium AAA would have about that voltage. Lithium-ion doesn't come in 1.5V cells. A better choice would be three 18650's (between C and D size) and a regulator of a couple of dropping diodes.

There are many newer sizes of LiIon cells, but the 18650 is a well-known standard, widely produced and economical (for Li-Ion).

[drdn0]

I reckon you'd have much better luck using 12/18v tool batteries - stacks of capacity, proven provenance and not that expensive.

Yes, you may need to regulate down to 9v but I'd trust that over an AliExpress battery pack any day off the week