For almost 20 years, Mercy Hospital (once called St. Mary's Hospital) has given me their "old" batteries. Batteries whose voltage remains "nominal" while supplying a current of an ampere or two are listed below and are given (free of charge, of course) to HAM (amateur radio) operators all over the nation (I once sent, via a HAM who was going that way, ten 12V, 28AH batteries to southern Florida from central Kansas for use in their hurricane season!), while those which fail go to the recycling center.
Over the years, I've received all sorts of batteries, from monster 100-pound 12V 100AH batteries to 50-pound 120V 4AH batteries to ounce-size cells. Most batteries are LEAD-ACID, but many are NiCd's and NiMH's, and some are so well encased that I don't know what they are! Long ago, I even received some "wet" NiCd's (think potassium hydroxide instead of dilute sulfuric acid), and about two years ago I was given two humongous-big/heavy 5 KVA UPS's (Uninterruptible Power Supplies; these went to Kansas City and Nebraska to power repeaters!)
In their replacement process, most of these recycled batteries are marked "BAD" so hospital personnel won't try to re-use them, but many of them last for YEARS beyond their replacement date. (In 2007, for example, I finally recycled a 12V 17AH battery which HAMs used to provide emergency communication for the 1996 International Horse Race!)
Sealed Lead-Acid batteries
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How Amp
Many Volt Hrs Other Comments
---- ---- ---- ----------------------------------------------------------
2 12 17 About the size of a motorcycle battery
1 12 3 Rated for C20 discharge rate
1 8 3.8 Rated for C20 discharge rate
4 8 2.7 These are "neat" batteries in that they are replaced on
a time-in-use basis and will probably last a LONG time,
but are probably rated for a fairly-low discharge rate.
If used (with appropriate cabling) in place of a 9-volt
"transistor" battery, it should last a VERY LONG time!
1 6 5 Three "Gates"-type cells in a triangular package
1 12 3? Looks sorta like a lantern battery with wire terminals
The following are shrink-wrapped instead of sealed and can be disassembled
and/or rebuilt by a (pick one: true? cheap? thrifty? desperate?) HAM!
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How Amp
Many Volt Hrs Other Comments
---- ---- ---- ----------------------------------------------------------
4 12 4 10 NiMH cells, each a little longer than AA-size
2 12 4 Same as above, but with some bad cells
2 12 3 NiMH, about "C" size cells
1 16 ? 12 AA-size cells of unknown type