Average Energy per match

[Stephen Kowski]

Originally Posted by Tom Line

We test our batteries, and have not seen the drop-off that you suggest (20%). In fact, some of our best batteries are not the new ones, but ones that are one or two years old.

If the manufacturer says 20%, they may be hedging their bets in case the battery is used in a critical application, or (more likely) are basing it on statistical sampling and covering the worst-case: for instance 99.999% of the batteries may lose less than 20%.

It is not my dropoff, that is from MK's datasheet.

How did you make that assertion that MK is incorrect? I doubt they are "hedging their bets".

What is the maximum SOC you saw when you first charged them? what C rate did you charge them with (C/10, C/20)? Now two years later when using the same C rate what is the SOC? Were you at the same temperature both times?

Or did you use some type of impedance spectrometer to correlate that to capacity?

Just because your robot still runs doesn't mean the battery hasn't lost capacity, back to my original question. Maybe your robot will function normally even if you lost 40%? What is the average energy it expended per match? Did you test it now two years later under the same conditions?

@squirrel, I wouldn't recommend charging them fully for long term storage from what I can tell 40-60% seems to be the sweet spot for %SOC with regards to reducing impedance growth. Also, keeping that ambient temperature in check is huge.

@Eric, check your PM box in a few minutes