propanutta

hi im new to lipo batterys and ive just got two that have been used of a friend and i charged them with a cheap lipo balancer and it reads low on one cell please can you tell me if this is ok,


3 cell 11.1v lipo

reads 4.18 4.16 4.06


the 4.06 is what i am thinking is low, is it

propanutta

lipo charger is a turnigy 5011

guver

My Feedback: (325)

Yes, it is low and should be brought up to match the others.

propanutta

hi thanks for the reply,

how can i make it match the outhers,

i have two used ones, 1 of wich i just posted with the low reading, and i have two new ones

these are all my readings

used bad battery 1 posted above

used battery2 4.15 - 4.11 - 4.15

new battery 1 - 4.18 - 4.15 - 4,18

new battery 2 - 4.14 - 4.14 - 4.13

please can you tell me what is right or wrong with these

guver

My Feedback: (325)

You can use a balancer, balance charger or simply charge the one single cell up to match the others manually.

If you do it manually use the balance tap at low current and careful not to short it out since the pins are very close together.

It is best to start out with them all perfectly balanced when full.

propanutta

thank you very much guver,
what is a exceptable limit, on lipos, its just if you look at my outher batterys some are close, should i still balance them, its just my charger seems to balance them like this, they dont balance the same, how would i balance one cell it sounds hard

guver

My Feedback: (325)

Since you are reading to 2 decimal places then they should all read equal inmop. Ultimately the amount of imbalance isn't important as long as NO one cell ever gets too high or too low. Even those limits are a bit cloudy. 4.2 volts for the top and 3.5 volts for the bottom.

If you're using a balancer or balance charger to balance then it really should get them much closer. You can manually charge this pack's (4.18 4.16 4.06) lowest cell thru the tap with a charger on a 1 cell setting until it matches the other two cells. It is possible your charger is reading voltages wrong?

rva1945

In case I can't afford a decent balancer, how about discharging each cell (taping into its terminals using the built-in balancer connector) to 3V?

guver

My Feedback: (325)

The "balance" at a 3 volt level isn't very important. It would be better to have the cells "balanced" at 4.2 volts. I would recommend charging instead of discharging. The closer we get to 4.2 volts the more accurate the balance since many times an imbalance is normal at low voltage levels.

rva1945

OK, but if I get to balance the cells at lower voltages, i.e. at the beginning of the charging process, they'll reach their top voltage equaized.

guver

My Feedback: (325)

Only if the cells are 100% identical capacity. Most are not , and many are way off. Many times correcting the imbalance at the start will be counter-productive at the end. If the pack ever was in balance then it is best to leave the cells imbalanced and allow the imbalance to self-correct as the pack gets back to it's recharged (balanced) state.