LiPo assistance needed...is this battery still ok??

[c_cormier]

I am new to the LiPo battery arena and I am trying to sort everything out.....

I fly a Belt-CP with a 3C 1800mah battery. I use the included charger/balancer that came with the heli. After using the battery pack for about 4 flights, it appears as though the pack is starting to expand. It is not much larger than the extra battery pack that I have, but none the less it is larger. My first time flying the heli consisted of quite a few "hops" and restarts of the heli, so if was difficult to tell how long I had actually been flying. I did notice the heli rpm slow down a bit, so it was at that point that I stopped flying. My guess is about 5-6 minutes of time.

What I am trying to fuigure out....Is it better for me to be flying for say 5 minutes whether I have to stop the throtle or not, or is an onboard battery monitor a better idea? Is the battery that is now a bit larger toast? or can I still use it?

Also I really do not know what is going on with the status of the battery. Is it fully charged, balanced, etc.? Do I need a better charger ?

Any thoughts would be great to make sure I don't hurt anyone, my helicopter, or my house.

Thanks :)



http://www.thecormiers.com/rcheli/lipo1.jpg

http://www.thecormiers.com/rcheli/lipo2.jpg



http://www.thecormiers.com/rcheli/lipo5.jpg

[mkoutnik]

When you first get a Li-Po battery, you'll first want to cycle your new battery 5-10 times only running it for about 3 minutes, let it cool, charge/balance, repeat. This will prevent any battery puffing that may ocuur if you push it too hard right away.

After break-in, I use the rule of thumb to run the battery down to about 80% of its original capacity (this prevents any possibility of discharging the battery too low)...e.g. 11.1 V, 2200 mAh, 3S battery is made up of 3 cells wired in series and will charge up to about 12.6 V. So, 12.6 x 80% = 10.08 V. You definitely don't want to run the cells below 3.0 V per cell or 9.0 V total! Be sure to set your ESC for the proper cut off voltage.

This should help...http://thunderpowerrc.com/PDF/THPSafetyWarnings.pdf

With all of that said, you can probably expect 6-7 minutes of good flying time per battery. Of course, this also depends on pinion/gear ratio used, and type of flying. I use the stock 13-tooth pinion on my mini titan.

If you plan on staying in the hobby/sport for the long-haul...I'd invest on a good charger/balancer combo. Get the best your budget will allow. Anything is probably better than what came with the heli...:D

Are those two batteries identical? If they are, it looks as if the bigger one is "puffed". If it is I'd contact the manufacturer - they may give you a discount on a replacement pack. If not, I'd deep-six it for safety sake.

[HeliDan]

When you first get a Li-Po battery, you'll first want to cycle your new battery 5-10 times only running it for about 3 minutes, let it cool, charge/balance, repeat. This will prevent any battery puffing that may ocuur if you push it too hard right away..

Wow, in all the data I have read on LiPos, I have never heard that. Is this just something you do, or is this supposed to be common knowledge?

Thanx

[andeck]

yea mate, a few cycles to break her in is a good habit to adopt

[FlyinLo]

Mystery solved: One pack is a 15c and the other is a 20c
The 20c is larger and heavier than the 15c