Verifying Capacity (mAh) of Lipo

[chngpe01]

I am quite new in RC and would like to know if there anyway or method to determine the actual capacity of a lipo. eg it says 5000mAh, how do I know it is actually 5000mAh and not 3000mAh.

I am asking cos I suspect that a couple of batteries I got are not up to spec and it does not give me any longer flight time on my multirotors, compared to the lower capacity ones..

Thank You in advance.

[rayonnair]

Use your charger. Drain it to 3.0 - 3.2 volts / cell. Recharge it to full. See how many mah goes in.

On second thoughts, I would start at 3.2v and see if you get close to the rated capacity from there. 3.0 is probably pushing it.

[elmosan]

Use your charger. Drain it to 3.0 - 3.2 volts / cell. Recharge it to full. See how many mah goes in.

On second thoughts, I would start at 3.2v and see if you get close to the rated capacity from there. 3.0 is probably pushing it.

Yep, a faster way would be to fly as you normally would to about 3.7V. Then charge it from there. You should get about 50% of the total rated capacity back in.
Benifits:
1. Less potential to harm battery since it uses only half a cycle out of the total lifespan. You save the other half cycle for your future flying needs.
2. Faster to do
3. Some esc auto LVC at 3.0-3.4V, you might want to check if trying to deplete it when flying. Control might not respond when LVC.

[chngpe01]

Thank you very much for the answers, rayonnair and elmosan. Much appreciated, I will do a test soon.

[REVOJohn]

Hi there.
Yah being in the battery game for over 15 years I see this "overrating" all the time,

1. Your charger should have a cycling function (auto charge and discharge and it'll tell you the capacity). Much like all the REVOLECTRIX chargers do,
2. Bring the pack into me and we'll hook it up to out auto cycling machine and you can see the results on excell for yourself. Free service. Industrial standard machinary

tks
john

[chngpe01]

Hi there.
Yah being in the battery game for over 15 years I see this "overrating" all the time,

1. Your charger should have a cycling function (auto charge and discharge and it'll tell you the capacity). Much like all the REVOLECTRIX chargers do,
2. Bring the pack into me and we'll hook it up to out auto cycling machine and you can see the results on excell for yourself. Free service. Industrial standard machinary

tks
john

Hi John

Thanks for the offer, I will take it up when I am back from India in Sep.

Thanks once again

chngpe01

[VioleEla]

Verifying Capacity mAh of Lipo

Is it true that a LiPo can discharge at 65C continuously, and 135C in bursts?
While a Lion RCR chemistry 18650 2900 mAH can only discharge at 2C or 5.8 amps max???

[REVOJohn]

lipo designed for rc yes can do 65c continous,, they will get hot and have a shorter life cycle and lower energy density....say 150wh/kg. other lipo for mobile applications can go as high as 210 wh/kg but yes only 2c discharge like the 18650 cell you stated.
might you lithium polymer is a myth. there is no such thing because the inventors of the true polymer battery breakthrough in 1998 were never successful and reverted back to li-ion chemistry and construction methods but in a pouch format. so li-ion and polymer..............same same inside