LiPo Discharge

[ekaser]

When I get done racing my Ms Geico on (2) Dynamite 2s 5300 mah, what should the voltage read?

Thanks, Ed

[mappo]

Anything above 6 volts a pack

[Derrick Davis]

Gentlemen, What should the voltage be at charge completion of a 7.4v 2s 4000 mah 25c lipo?
I have a pair of Tenergy packs that are only showing 4.10 volts on my commonsense blinky once the charge is complete. I believe it should be 4.20.
Using a hobbico dual battery charger. Your response and advise is appreciated.

[Fluid]

Fully charged LiPos should read very close to 4.20 volts per cell. Any more is a problem, and less means something is not right. Meter accuracy could account for a few hundredths of a volt difference, but a full tenth means something is wrong. Bad cell, bad charger, bad balancer.

If you want to store your LiPos, the storage voltage should be around 3.8 volts per cell, about a 50% charge level.

.

[Derrick Davis]

Thanks Fluid. I may have an incorrect setting on my charger as these are fairly new packs. I'll check it out.

[sailr]

If you are giving it a FAST high C charge, you probably won't reach a full 4.2V before the charger shuts off. A lower C charge will get it up there.

I have done high C charges, 2 -4 C and noticed the cells never quite reach 4.2V . BUT, if I put the batt back on the charger and reduce the charge rate, it will peak them on up to 4.2V

It's really not that critical. The top of the charge, 4.2V only lasts considerably less than a minute anyway before the curve flattens out to a consistent rate and then falls off to your cutoff voltage at the end of the curve.

I have some turnigy packs too and have noticed they never quite get to the full charge unlike my hyperions.

[Derrick Davis]

Thanks for the tip Sailr. Turns out I had the charger set for 7.2 v NOT 7.4 like it should have been. Cells now top off at 4.20 volts. I'm a goof sometimes. Must be getting old.

[sailr]

A fully charged 2 cell pack is actually 8.4 volts. 4.2 per cell. Generally, packs are rated at 3.7V per cell as that is the NOMINAL voltage. Thus, a 2 cell pack is usually listed as 7.4V.

Glad you figured it out!!