86 year old Edison Nickel-Iron cells discovered, tested

[protomech]

PDF link

Worth a read in its short 7 page entirety, but here's the gist.

Short version: author finds batteries of unknown make on craigslist that have been servicing a lighting assembly in a cabin in the woods for decades and decades. Travels out, hauls them back, tests them.

Initial tests are pretty poor - the cells would collapse after several minutes at even a light load. After an electrolyte replacement (the acid in a lead acid battery) the cells seemed to significantly recover.

The 300 Ah cell listed in their testing was initially rated for 60 A for 5 hours (discharge down to 1.2 volts per cell, vpc). They tested it at a 30A, 20A, and 14A discharge .. 30A was still too high, but at 20A it lasted for ~5.5 hours, and at 14A it lasted for ~7.5 hours.

So approximately 36% original capacity after 86 years of abuse and neglect. Not too bad.

[00049 (AKA SopFu)]

Edison cells    Weren't they the company that said batteries would never matter, while secretly doing tons of R&D to figure out how they could make them work?