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View Full Version here: : LONG term storage of Li-ion batteries


LewisM
13-01-2020, 05:59 PM
Not a how to, just an observation.

Tidied up the garage yesterday, and discovered our 2 Panasonic DV camcorders. Both have not been used in 11 years, as the LAST thing they recorded was the birth of our first child :)

I put one of the batteries on, not expecting it to have ANY juice whatsoever...to be surprised it was at 100%. Tried the other 2 - one sitting on around 80%, the larger of them all having still 50% on it (the battery we always used). Turned on both cameras, both played from the tapes perfectly, both displayed from the SD card perfectly. No mold or crud on the tapes at all. Plugged both in to the TV (after finding the Firewire to USB converter :) ) - no issues. Decided not to relive the birth of No1...chosing instead to watch the footage wife took of us travelling accross the Nullabor and along the Bight on the way to Perth all those years ago.

Reminded me of the time I pulled the old Nokia 2G phone out of the glovebox in my car since the 2G network was shutdown, it's no longer useful as a backup/emergency phone :(. Turned it on...100% battery...and that had not been on for 15 years.

Do they build stuff like this any more? I know my old iPad mini will hold 100% turned on but static for at least a week and a half, and my Air will hold it for about 7 days, but not 11 let alone 15 years I am sure :) Heck, my iPhone SE seems to lose charge just looking at it, turned off :lol:

DarkArts
13-01-2020, 08:32 PM
The scuttlebutt is that i-devices are never truly off. A better test would be to remove the battery (if possible!) and store separately, then test.

Though I never did a proper storage test, my old Nokia 3210 (?) had a fantastic battery that lasted over a week (albeit with very few calls) and held charge when off for several weeks.

Icearcher
13-01-2020, 11:03 PM
They don't build them like they used to :)

I suppose thats the problem with advancing battery technology, to get more capacity, something else has to suffer.

glend
14-01-2020, 02:11 AM
There are two killers of Li batteries, excessive charge cycles (they have a limited number of recharge cycles) and over charging (which damages the cell chemical barrier). They have an optimal charge voltage and should not be charged just because they have sat around and not discharged. Cell life can be extended by holding the charge voltage at about 3.7V, for a 4V cell; this has been proven in the electrtic bike industry.