what figures to log for long term battery health/monitoring

[cudaboy_71]

i've been flying electric for going on 4 years now. i've gone through a slew of packs. and, currently i have 12 in rotation between all my different helis.

thing is, after all these years and all the packs, i really don't have a good idea of which brands/packs seem to perform best overall. i know which of my current packs perform best NOW, and i know when i got them (age). but, i havent been tracking temps, discharges, voltages, etc....so one pack might have been better than another except i haven't been tracking abuse which could affect pack health.

i'm thinking now that it would be quite interesting to look back at the history of the packs, had i been tracking them. too late for these packs. but, i'm just curious if any of you battery gurus have any suggestions:

what *SHOULD* i track to have some good data to look back at a year from now? i have a logger. but, i think it's a little unrealistic to log every flight...especially since i'd have to move it between 4 different electrics...and, i rarely fly two flights on the same machine in a row. with that many helis ready to fly, i usually rotate between them letting the motors cool down.

i'm thinking:

time of flight
temp of pack after flight
mah put back in
number of cycles
crashes

is that enough data? any other suggestions? any ideas of what to do with the data to make it useful? (plotting the data in excel comes to mind...but, something else maybe?)
what might i do with this data to make it useful for others? what kind of data would YOU all like to see if i were to open/share the data?

just some stuff to think about late on a sunday night :smokin:

[th3tick]

Well, I've taken the opposite approach, and put an eLogger on all my helis, and log every flight. I've kept all the data you suggest, plus mAh drawn, and low voltage seen during flight, plus any notes on behavior. I haven't logged post-flight temps, however.

I keep this all in an excel spreadsheet, with one sheet for per-flight data, and another with per-pack data, summarizing things.

Yeah, it's overkill, but I know most everything about all my packs.

John

[cudaboy_71]

interesting. but logging every flight just ain't gonna happen. not that i don't want the data. but, i know myself. i'm just not fastidious or diligent enough to follow through with downloading data for loggers every day (i fly 6-10 flights every day).

but, thanks for the info. i just want to track as much as i can reasonably log.

[raylepper]

I log all but the temp. (People see me doing it and groan, "what a dork." But I always logged my full scale time, so...)

It's also pretty useful when you change something, like a belt or head or radio setup, to see the effect. A couple months ago I switched belts and reset the tension on my 450 and got an extra 1/2 minute.