Way to test for C rating?

[helocat]

Way to test for C rating?

I just received two non labeled batteries from a supplier over seas. They claim they are 5000mh 27C rated packs but there is not label on them. Is there a way to test for the correct C ratting as advertised?

Thanks!

Mark

[spork]

Way to test for C rating?

I just received two non labeled batteries from a supplier over seas. They claim they are 5000mh 27C rated packs but there is not label on them. Is there a way to test for the correct C ratting as advertised?

I assume you mean the current capability (i.e. 27C) - right? I'd think the best thing to do is use one of those in-flight power data recorders and put the heli through it's paces. Pump the collective some, a few hard climbouts, etc. Then check the data. If the pack claims to be 5000 mah and 27 C it should be able to put out 135 amps in theory (5 amps x 27). To test the total capacity, just fly it until your alarm goes off (maybe 3.1 volts per cell ?) and see how much you put back in when you charge.

[Pinecone]

You can use a West CBA, battery analyzer to run some curves, starting with say 10C and seeing how they perform.

Otherwise, figure that they are overrated and run a good bit low discharge rates.

[kamtsa]

You can use a West CBA, battery analyzer to run some curves, starting with say 10C and seeing how they perform. Otherwise, figure that they are overrated and run a good bit low discharge rates.

The West CBA looks interesting but very expensive ($700 if you want to go beyond 150W which is about 15A for 3S). Any similar product but let expensive.

I am looking for an objective method to test my batteries.

Kam