Lipos not fully charging ??

[bulnose]

Trying to charge 6s 3000mah Opti's on my Cell Pro 10s charging, but it's only charging the lipos to around 89%. Each cell is only reading around 4.05 when usually they're around 4.15.

I noticed when I flick through the different modes (while the lipos charging) one of them says CH1 LIPO COLD W.

Are they just not fully charging due to the cold ??


Thanks

Havent got your chrger set to lilo istead of lipo have u ? :~P

[moonmanflyer]

It is a known fact that cell voltages increase when temps go up, hence the cold charging only putting in 90%, if you we're then to place the lipo in a warm area the voltage on the cells would increase.
when out flying in the cold it is a good idea to try to keep your packs warm, I have even had packs in my pocket before.
someone I know has even converted an old mini Stella fridge into a heated compartment to keep lipos in on cold days at the field, you can even now by heated picnic boxes that work a treat to

[miniman]

I have yet to see any conclusive evidence to suggest the voltage rises under no load when going from cold to hot, Could you tell me where your getting this from?

I used to work for a company that manufactured Lixx cells for automotive use, and get my knowledge from there. The charging circuits on cars, takes the temperature into account to avoid this problem. This is so important to the life of the cells, the computer will automatically discharge the cells to keep them at a safe voltage should the temperature of the cells rise.

Peter

[cjcj1949]

But if you measure our lipos there is no change in voltage with temperature. It may be true that safe voltage levels need to be reduced as temperature changes, but there is no evidence for this. This is very important as there is information that says it is better to store cells at 4.20V in the cold. Can you contact someone at that company and find where their info comes from. I've looked at panasonic information lately and there are no restrictions on their data sheets.

[miniman]

But if you measure our lipos there is no change in voltage with temperature. It may be true that safe voltage levels need to be reduced as temperature changes, but there is no evidence for this. This is very important as there is information that says it is better to store cells at 4.20V in the cold. Can you contact someone at that company and find where their info comes from. I've looked at panasonic information lately and there are no restrictions on their data sheets.

I beg to differ and have seen changes of between 5 & 10% on our own cells. I generally fully charge the packs we have at home, then check them, an hour or so in the cold they are down by 5% or so. Keep them in a warm place and they stay at the same % charge they were at home in the warm.

AS I wrote the information for the company there is not much point asking for it Most companies write the temperature charge/change variation in there technical specs, we are the only section of the global battery business that the manufacuters do not supplyor quote full specifications on the cells we use. The automotive manufacturers would not touch the cells we use, and I belive that we are given the cast offs from the main users of plastic film cells.

Peter

[cjcj1949]

The volts do drop after charge. Nothing to do with temperature change.

[miniman]

Granies, sucking and eggs come to mind.

That was taken into account.

peter

[cjcj1949]

Giantshark • View topic - Lipo Charging in the Cold?

Try Wayne Giles.

[David Drew]

1) Trust the cold charge of the Cellpro. I do. A minute or so less flight time maybe.

2) Charge in the warm and keep the lipos at the same temp or lower.