Lipo battery enigma

[jlaurienti]

I have a 6s lipo battery that registers "no battery" and "0" volts on all six cells when tested on the main leads (XT-60 connectors). But it shows normal voltage on all cells when tested on the balancing lead!

At first, it got a "no battery" alert when I hooked it up to my Electrifly charger. So I replaced the main leads, cutting off the originals on the suspicion that there might be a discontinuity of some kind in the wires. (While I was doing that, inevitably, I accidently shorted, for just a heartbeat, the main leads, and got the usual spark.) After I replaced the leads, I tested it again on the watt meter, and nothing had changed! "No battery" on the main leads, and 4.1 happy volts on all six cells and 97% health, when tested on the balancing connector.

The only change was that the charger finally did acknowledge the presence of a battery, and topped it off. It also runs normally on the plane, but I'm skeered to death to fly it.

Nothing wrong with the watt meter. Other batteries test mormally.

Anybody have any ideas?

[Wildflyer]

You must have a broken connection inside the battery wrapping.

As I understand, you get no voltage from main leads, when battery is out of the plane.

And since it runs normally in the plane, somehow the intermittent connection is being pushed together, when you put it in the plane.

I agree do not fly this pack.

Once you cut off the heat shrink wrap around the battery, you get into an area that only experienced electricians should be in. A battery like this can catch fire or almost explode, if you short it. I have seen spaces of only 1/32" between different levels of power. If you dropped anything conductive in that space, you will not like the results.

I would recommend discharging the pack through the balance leads and dispose of it.

If you flew it, some where during the flight, the connection would open up, and there goes your plane. Cut your losses and get rid of the pack.

[jlaurienti]

Thanks! It is not worth the risk to an expensive airplane, not to mention my pretty face, to fool around with this thing. I will discharge and dispose of the thing.

[hayofstacks]

I have re soldered several battery packs. Some of the eflight and tiger power packs I have played with have some sort of curcuit board in them.

Every hobbyking battery pack I have cut open had almost a 1/4" solder spot on each cell that looked like a drunk 4 year old did. My dad has soldered many of these and the ballancing plugs back together. Some of them after trying to disconnect the ballancing plug from the charger on a new battery.

These are only 3 cells, not sure I would want to do the same with a higher amprage 6 cell.