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Re: Eneloops: 5000 cycles and still going...

Posted: Mon Nov 28, 2016 7:02 pm
by Benediction
Any progress?

Also, it might be interesting to find the testing criteria established by International Electrotechnical Commission for battery testing.
*charge capacity and mAh estimates based on Panasonic internal IEC 61951-2(7.3.2) testing.
**Recharge cycles based on testing method established by IEC 61951-2(

Obviously, only some of the battery types have existed for 5 years and virtually no LSD have existed for 10 years so there must be some way of calculating self discharge out to that time limit. In addition the cycle counts, have they really performed 2100 cycles? (note: they do have more advanced industry testing equipment such as a Cadex C8000 ) - perhaps they use Weibull probability plots?Battery Reliability Testing

Cadex C800 abilities:
    * Maximum Charge/Discharge Current 30mA to 10A set in 1mA increments
    20A maximum discharge rate using Dual Power Port cable
    *Nickel-based: Constant current; negative slope or plateau timer, trickle charge

Re: Eneloops: 5000 cycles and still going...

Posted: Tue Dec 06, 2016 11:23 pm
by Mark
Benediction wrote:Any progress?

Sorry - I haven't got to it yet...

I have previously look at IEC testing methods - If I recall correctly, the biggest hurdle in implementing them is to maintain consistent room temperature. Another difficulty was that the testing that I was looking at was at relatively low rates and for consistency would really need to be done with only 1 cell per charger, so wasn't really an efficient use of chargers in my opinion.

Re: Eneloops: 5000 cycles and still going...

Posted: Sat Oct 28, 2017 4:54 pm
by Opi
Mark, on the graphs you created showing the long term cycle life of eneloop cells, I assume you pulled the ending capacity data from each completed cycle to make the chart, is there an easy way to do that without manually searching and then copy and pasting that data pulled from each completed cycle from the combined log file? Might you have a script that's available to share that might automate that task?

Re: Eneloops: 5000 cycles and still going...

Posted: Sun Oct 29, 2017 11:43 am
by Mark
Yes, I did write a simple program to go through and pull out the info from the log files - I'd have to go searching for it to find it though.

Re: Eneloops: 5000 cycles and still going...

Posted: Thu Nov 02, 2017 10:46 pm
by Mark
OK, you can download the program to extract the capacities from the CSV files here:

It will automatically read all of the csv files in the current directly and then create an output.csv with just the capacities from each cycle.