Before Heaven, why, why, why am I stuck woith all these necros...

Pipe down and get to it.

Anyway. NiMH was the top end for long duration for its day. The new kids on the block are batteries that use lithium compounds. The one most able and stable although not #1 efficient (but close) is lithium iron phosphate (LiFePO4)... Mostly known as Lifepo's.

Tech side information is here...https://en.wikipedia.org/wiki/Lithiu...sphate_battery and I've been trying to weed thru the various vendors to avoid duplication.

The big sell is that it has a very very low shelf discharge rate and a reasonable weight advantage. That and Very old Lifepo's apparently don't corrode and be chemically hazardous... they just collapse into a rust inside the battery. ( Having to take up the excessive slack at my WM by 'helping' out the auto department, I've had to pull more than my share of batteries where ijits had yanked off battery caps, or the damned things were indeed SMOKING... and having to get the damned things out of the building and get PPE to drown the damn things in pool sized baking soda, them looking at us bovinely as we looked at them with "How in HELL did you get that out of the car and you not burned?" looks... But I digress)

Me, I'm wondering if older battery materials might be thought on for post SHTF. Allesandro Volta's voltaic pile was copper and zinc discs separated by saltwater moistened cardboard... and such an item would lend itself very well to ease of assembly and salvage. Putting a fan on the top of of the pile to vent hydrogen might make them last longer. I'm trying to remember what the old "wild West" era telegraph batteries were powered by....

K