I will be the first to admit that electric systems are relatively new to me and I have a lot to learn. I have been trying determine the battery power consumption and available flying time in my newest scale ship. It is driving me nuts to try to figure this out.

My current system uses two FlightPower 4350 mAh 3s 30C Li-po batteries wired in a series. The motor is a Hi-Max 900W unit with a Castle Creations ESC. The other day, I was out doing some practice flying. Nothing in particular, just practicing before the NATS. Upon returning home, I pulled both batteries out of the plane, separated and recharged them with my Triton 2 charger. One took 600 mAh to recharge, the other took 1200 mAh!! Being wired in a series, should they not have been more or less equal? This raised my first concern.

Then, yesterday I took the plane out to practice just one flight routine so that I could possibly make a consumption assessment from that. It is not a long flight routine, maybe 3 to 4 minutes. I then took the plane back home and charged both batteries again. The each took about 225 mAh to recharge!!! I expected it to be way more than that.

At that point, I tried to do something more controlled than flight time. I charged one of the batteries (I have four) to full capacity. I then discharged that battery by the exact amount of 800 mAh. The I immediately recharged that battery, allowing the Triton 2 establish the shutoff. It took 1255 mAh to recharge to capacity, 50% greater than the controlled discharge! I no longer know what to do. The batteries are about two years old, without a lot of flight time and have been stored at about 70%. The Triton 2 is much older. Do you think that either one of these are going bad? Do you have any suggestions? Thanks for your help.

Jim Fruit

Hi Jim,
This sounds like an interesting troubleshoot ...
Let's start by proving that it isn't the charger.
Like Bob said, charge a pack ... you are using the balancing feature, right??? ... and then immediately afterward check each individual cell voltage (4.XX V) resolution or better please.
Then do as he says and recheck after a day or so.

take care,
  Dean

Thanks, Guys. I used Bob's recommendation to verify the battery conditions. Two of the batteries were at least 12 hours after charging. Two were 24 hours after charging. All of the cells were within .01 V of each other except for one cell that was .05 V higher. Each two battery group was within .01 V of each other (24.65 V to 24.64 V). So, I am satisfied with the condition of the batteries. Then, I believe Dennis' description of how his Triton would pump in more mAh during the balancing stage of charging probably explains the difference in total mAh between batteries. If one of the batteries from a set was less balanced after use, it would probably take more time to balance it. I think both the batteries and the charger are OK. Thanks again for your help, you saved me a lot of bucks.

Jim Fruit