charge 6 X 3.6V LIR

I have 6 uds LIR 3.6V, and my charger can charge 5 li-ion in series.

what is the best metod to charge all my batteries??.

all in parallel?

thanks
luixi

sure all in parallel. but before you must check that they have the same voltage. cause if you put in parallel a 2.9V batt and a 3.9V batt this last one start to charge the 2.9V one, but due the high difference of voltage the 2.9V sure will take too many amps (more that the recomended 1C).

the max difference of voltage between batts must be under 0.2V

and you can charge li-ion in series ONLY if you have a circuit that balance each of them during the charge.

Hello David,

The RC people did a study on this and found that even if you take a fully charged cell (4.2 volts) and parallel it with a fully empty cell (3.0 volts), you will have no problems.

There is a pulse current when you hook them together, but it is of such a brief duration that it has no effect on the cells. I should also point out that Li-Ion cells are rated for 1C continuous load, but can sustain much higher pulse loads.

Tom

i haven't fear about the charged cell (4.2V), i know that i can handle discharge of 2C or more. my fear is in the discharged cell that usually can't handle more that 1C of charge (even if i prefer to use 0.5C or less).

can happend, with 6 cells, that you connect in parallel the more charged batts and like the last the more discharged. if for example are 18650 2200mah, is like to put in parallel a huge 11000mah battery against the last 2200 batt.

maybe is safe to do... but i still prefer to balance the voltage before do this ;-)

Hello David,

I decided to take another look at the testing that was done by the RC people. They finally came up with a value of under 0.5 volts difference. While there is a theoretical 5 amps of current instantly available with this difference, only around 2 amps has been actually measured, and that was with partially charged cells.

The other thing to consider is that if you are charging discharged cells, their available capacity would be near zero. I can see an issue if you hooked up 5 fully charged cells with 1 totally empty cell.

Your 0.2 volts of imbalance seems conservative, but should work well.

Tom