Project Farm's 7 year Eneloop update

[Beacon of Light]

White envelopes and equivalent quantity nimh self discharge much slower than that.

You are simply overcharging the cell doing this. Due to the full charge behavior of the nimh chemistry, nimh chargers aways take considerable time to detect that an already full nimh cell is full, especially at low charge current relative to the cells capacity ( low c-rate is the correct term).

Cells date code says May 2006. surprised it's still even working almost 20 years later.

 

[dc38]

I was hoping I'd be able to put them on the charger and it would show up as full or at least not take another hour to add another 270mAh. Is that a fake number? I'm charging at a low 300mA but am I gaining capacity every day, as it keeps adding about 200-300 mAh? How was it full less than 12 hours ago, and then today it sat on the charger for an hour and added 270mAh? Did it discharge that much mAh within the last 12 hours just sitting idle?

Typically, if all your cells are doing this, then most likely the charger is slow cooking the cells

 

[Beacon of Light]

Typically, if all your cells are doing this, then most likely the charger is slow cooking the cells

These are 20 year old cells, likely bought after I joined this forum in 2005.

 

[dc38]

These are 20 year old cells, likely bought after I joined this forum in 2005.

From my limited experience with eneloops (a little over 10 years) they don't really go bad, but I'm only an average of couple hundred charges in for most of the cells. However, if theyve been dropped or physically abused, it's possible that the guts are no longer LSD. I'd say to leave them unused for a few weeks/months, then check the voltage. If you have a flashlight with an established runtime/power draw, see how long it lasts with those rested cells, record, fully charge, use those same cells fresh off the charger, and compare that runtime with the rested runtime.

 

[Eugene]

Most of my eneloops date back to before 2010 and are all still working. I'm slowly buying eneloop pro for lights.