So i recently completed my quadcopter, and have been in the process of really testing it out and getting it ready for a full flight. I have had a problem getting the APM to read that it is a 4s battery. it seems to operate fine other than the fact it doesnt give me the 4 beeps at start up that i believe it should.
I suspect it is because i didnt charge the battery before testing it out ( took it out of the box and plugged it right in, not sure if lipos come fully charged.)
This brings me to my bone headed move this morning. I finished charging one of my 4s packs, and walked over to plug it into the quad. I had the other pack strapped to the quad, and instead of grabbing the connector for the quad, i grabbed the connector to the other battery on accident. Having the cheap hobby king bullet connectors on them I managed to plug the batteries into each other and short them out. It was for a short second so im hoping theyre okay (especially since that is $90 worth of lipo battery down the drain if theyre bad) I have them both in the lipo fire bags and in a kitchen pot sitting outside just in case. The connectors completely melted and charred where the short happened. Not the worst thing ever since i was planning on putting xt60 connectors on them anyways, but if the batteries are ruined im screwed.
So i suppose my two questions are:
1.Why is my APM not reading the 4s battery pack? is that a low charge thing or something?
2. How can i tell if my brand new battery packs are ruined or still good?
Replies
1.- not sure what you mean by "APM not reading 4s..." - first, measure all cell voltages.
2: provided that all your cell voltages are good, (at least >3v)
Usually, you should check if the battery cell(s) got "puffed" - like a gas fills the bags where a cell is. it would get softer to touch, and increase in "height".
Additionally, you should check for internal resistance, not only for the cells, but the interconnects between cells.
If you don't have equipment for that, you can do it by comparing voltage drop at 10c load , and compare to another battery of of similar age and rating that is "known to be good".