Charging and Maintenance of LiPO Batteries

I don't know if I can give you a lot of information on this but I have read up on the C ratings of the batteries. The C rating times the mili amp hours gives you the maximum discharge amperage of the battery so a 1000mAH 15C battery can supply up to 15amps. I don't know if this is the same for charging but I would guess it would be, so for a 1000mAH battery 1c would be 1000mA (1 amp) and for the 300mah it would be 300mA (0.3 amps). You didn't give the C rating of the 300mAH battery but lets say it was 15C like the other one that would mean 300*15= 4500 /1000 is 4.5 so you could draw a max of 4.5 amps to run your rc plane.

I would search some of the RC forums as they would likely have more and better info.

Hi Frank, thanks for the quick reply. Knowing what the "C" rating is, is a big help After I posted the questions, I peeled off the label on the 300mah battery and found, "not to exceed 1C when charging", so I take it as no more than .3 amps per hour.

What I'm still confused about is, does the balancer recognize 3.7v or the 7.4v for charging? And discharging, does the balancer recognize 3.0v per cell or 6.0v per unit as the cut off voltage? The charger can be set to either voltage. I just love user manuals that tell just enough to totally confuse a person. I know with "old fashion" chargers, w/o balance, you'd set it total voltage, 6, 12, 24... volts.

dadw5boys, I don't know why you posted as OT, your comment is right on the subject line!! After doing some more research, I found this, (1), (2), (3), this one shows a lid on a fish tank raising after an explosion! There's a lot more video's if any one wants to take the time to watch them. I found these after I posted my original questions and trying to avoid a "Nuclear Meltdown"!! Little did I know how close my statement was!!

@ Frank, I don't know why someone rated your answer OT, I know that I gave you a GA, Thanks again, Dan

Yep! You're correct about the manufacturer C ratings of Li-Po batteries, but there are some not so obvious spots in the story. C refers to actual capacity and not the nominal one which is almost always exaggerated by some 10%-30% and gets worse as battery ages. 4.2 volts is maximum charging voltage but it's valid only while charging at 0.1C or more and is not a safe voltage to keep the cell at. If you keep a Li-PO at 4.2V permanently it's a matter of time to burst. Safe continuous voltage is at about 4.05V or lower for perfect condition never overcharged or overdischarged cells but you still put a lot of stressing and for better shelf life (storage etc) shouldn't go over 3.9 Volts. S.M.

1C does refer to the battery capacity (e.g. 3000mAh = < 3A charge rate) as suggested, so set the charge rate to anything at, or below that. The only difference will be the time taken to charge. The lower the rate, the longer the charge but the safer it will be.

You have got a dedicated charger, so you should be able to set the charger to 2S or 7.4V (as you suspected). You have an automatic cell balancer on the charger; it should be a three pin device for your battery (you may get several different types or adaptotors for different number of cells with this model). Make sure the pins are the right way round.

Plug it in, set the charger accoprdingly and it will take care of things for you. If you have set it incorrectly, most likely you will get an error message so you will get a chance to look again at your setup.

Don't worry. It will be OK.

Steve.

First, it is important to set the charger for the right battery type, so set it for LiPO. Second, you need to limit the charging rate, depending on the size of the battery. As others have said, a 1C charge rate for a 1000mAh battery is 1000mA, and it is safe to use a lesser charge rate, but not a greater.
Third, you need to make the right connections. Looking at the pictures on the charger website, it appears that you might need to connect both the charger connector (the multipin connector) and the main battery connectors. On my charger this is not necessary, because there is an individual charger for each cell, feeding the multipin connector. Yours might have a single charging circuit with the multipin connector feeing a balancer. Read the manual.

Thanks to all of you for the help! Knowing the "C" capacity is key to setting this thing up.

It's a sad state we live in, when a company feels it's necessary to dedicate 18 pages of a 28 page user manual to "Warning and Safety Notes", (Liability disclaimers)! They seemed to have lost focus on what a user manual is for- to properly set up the charger. Before I posted this on CR4, I went to the manufacturer's web site, only to find blank pages! So, I give TWO THUMB'S UP to CR4 and the people on here! Dan