Two Li-Po's at full charge read as follows:

Yellow lead...4v
Blue lead......8v
Red lead......11.1v

These are new batteries and 2 out of the 3 cells will not devlope full charge. This cannot be NORMAL even though I got two doing the exact same thing. Are they BAD?

Is yellow cell 1? then blue is cells 1 and 2? and red is all 3 cells??
That would be my guess. individual cells should only be *****g out at 4v , they are wired in series to make your final voltage 11.1V I use a digital voltmeter on mine...and only check output voltage on the jst connector..and it reads at 8.28V for a 7.4 800 mah lipo. Go to
http://www.commonsenserc.com/page.ph...913ff45976e3f7


check that out and see if that helps you any.


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Of all the things I ever lost......................... I miss my mind the most!

Thanks. You know, I thought of that series thing in my mind but it didn't click. You could be right. This is driving me nuts. Maybe it is the 4-1 causing all the grief (got a new one comming). Will I ever be educated when I nail this down or what?

I visited the site on batteries...yes...progressive series wiring. The batteries are fine.

actually crashcrash, your 3rd cell is way out of balance and is the likely cause of your problem.

cell 1 = 4.0V
cell 2 = 8V - 4V = 4.0V
cell 3 = 11.1V - 8V = 3.1V

your batteries need to be within 0.1V of each other or bad things happen, including poor performance. also, a lipo cell must never drop below 3.0V or fire may occur. your 3rd cell may easily be driven below 3.0V in flight with the power supplied by the 4V cells. you can use a commercially available balancer, or do it manually by putting a resistor (10ohm 5W wirewound) across the higher cells until they match the lower one, then recharge and recheck. repeat until they finish charging balanced within 0.1V. use the wiring code i wrote for you below to check individual cell voltage (and to manually balance them).

cell 1 -> black(-)/yellow(+)
cell 2 -> yellow(-)/blue(+)
cell 3 -> blue(-)/red(+)

btw, 99.9% of lipos around today are fully charged at 4.2V, which would make a fully charged balanced 3S pack have 12.6V. 11.1V is the nominal (or average) voltage. if you're curious, the other 0.1% of lipos are an obsolete variety that finished charging at 4.1V instead of 4.2V. they are no longer manufactured, and the standard is 4.2V.

I'm measuring black as neg, and going to yellow/blue/red so it comes out as:

4.1 on yellow-1 cell
8.2 on the blue which is cell one and two
11.1 on the red which is all of them.

I'm not saying they're not off balance because I'm using an analog meter and it's not that precise. I cut/pasted and saved the above for reference tho.