hey guys
i had a question
i have a 3s lipo [1500mAh]and a imax b3ac
and i always had  a problem with it
the two cells would turn green but the last cell always used to stay red ... disconnected and connected again but doesnt work... the charger get hot for the first 2 cells and then it cools down when the 2 are charged
So, finally i went to a local shop and bought myself a multimeter
the cells reading after full  charging[apparently 2 cells green and 1 cell red]
cell 1:- 418
cell 2:- 424
cell 3:- 407[the red cell]
total:- 12.49
the total cell rating should be 12.6 after charging right so using this 12.49 is okay
cause the charger just stops charging  

Clearly the LiPo pack is unbalanced. Only a slight variation in the second decimal is okay. That is, 4.18-4.19-4.18 would be considered okay for a 3-cell pack. Try balancing the pack. If that doesn't work, it would be wise to dispose of the pack. 

Secondly, the pack must charge to 12.6V if it isn't too old. The problem could be with the battery or the charger. I had a similar charger to yours which couldn't charge to 12.6V either. I got an Imax B6 and have never had any charging problems since.

Hi Watch this Video this might be helpfully

hii have you figured out the problem.is it charger or the battery.i too am having same problem. two of my lipos got same problem. one led remains red.using b3 charger

Shyam,  that charger is hopeless and does not balance charge so it might spoil your battery
Please buy a b6ac or some other

Yes, the B6 costs more but will never give you headaches like the B3 does. Think of it as a long term investment.

Regular LiPo batteries with nominal Voltage of 3.7V should not be charged greater than 4.2V.
Going above 4.2V to 4.3/4.35V is HVLipo territory. THIS SHOULD NOT BE ATTEMPTED ON REGULAR Lipos!!!!
The overall chemistry of the HVLipo is different compared to the regulars.
Plus even your average charger has a cut of limit of 4.2V, meaning it cannot charge beyond 4.2V.
If your regular XYZ charger is able to charge beyond 4.2V, it means the charger is faulty. 
I agree with Swapnil, right investment on a charging station will go a long long way!

Cheers,
Sree!

Cell no 1 in both of my batteries  remains about 3.7 it doesnt cross 4v. I hope the batteries are good and must worry about  the charger. Right!!!