For this article, you will get some tips on how to recover over-discharged Lipos.
As there are more and more people use discharged lipo, a question stands front of them. Due to over charge, the battery will lose the very high quality after many times use.
There is a way which is popular in the forum, it may give you some help. All you need to do is get a NiMH charger, and set it to the approximate voltage to your Tattu professional UAV lipo pack. (I.E. 7.2v for a 7.4v pack, or 12v for an 11.1v pack) Now, plug in your lipo, and set the charge current for ~1/3-1/2C charge rate (1/3c for a 1000 mah pack is .33 amps, 1/2C for a 1000 mah pack is 0.5 amps) and start the charge.
You only need to charge the lipo for a couple minutes to bring it back to the proper voltage for your lipo charger to recognise it, and charge it again. It is important that you keep a constant watch on the lipo while charging it with an NiMH charger!
If your lipo is still not recognised by your charger, then charge it a bit more on the NiMH charger.
The man rescued three packs by charging to 3+ volts per cell in Nimh charge mode, then continuing with the normal lipo charge mode. He supposes that a lot depends on how old and how deeply discharged the pack was and how long it was in that condition. Normally happens when people forget to disconnect and remove a pack from the plane at the field and discover the mistake the next day or so. Watch for swelling etc. of the pack while charging. It should take the normal number of milliamps to fully charge. Good idea to check the balance of the pack after charging.
Note: Some lipos may last for numerous more cycles, whereas others might only last a couple more cycles before they die completely. Your results may vary. Also, buying the batteries in good quality is also important.