Hi friends.
I've got a 3DR Hexacopter that has been using a Turnigy nano-tech 6000mah 4S 25~50C Lipo battery bought at HobbyKing and that has been charged only 2 times.
The last time I've used that battery was about 15 days ago, and I since the weather forecast showed that it would be stormy for too much time, I've decided to discarge that battery completelly to store it safely untill better weather days would come. The discharge was made in the hexacopter untill the propellers didn't move anymore.
Today I decided to recharge the battery and the usual Turnigy Accucel-6 50W 6A Balancer/Charger and i've discovered that it was detected only 2 cells.
I'm afraid that the battery is wasted, for that trying to fix this or charging it like if it was just a 2 cell battery would be too dangerous.
With that said, I would like your to know your oppinion about what might have happened, if it was my fault by having it completelly discharged with the hexacopter, by letting the cells fall bellow 3V per cell (like I've read somewhere which I can't find now), should I had used the Accucel to discharge it, or was it just my bad luck for buying a faulty battery? Anything?
Is there any list of good practices of how to care a Lipo?
Thanks in advance for your replies
Best regards,
António
Replies
If your charger has a NiMh mode, you can try trickle charging it at the lowest setting until it's recognized as a 4s battery again. Its really not that dangerous, just be smart and do it in a ventilated fireproof place.
Thank you very much for your help, all opinons were highly valuable.
I've learned a lot now and it wont be repeated, it was just a noob's mistake, thinking I was doing it right.
The problem is that there's just so much information that you many times get lost and miss important things, like in this case.
The ideia of trying to revive that battery slowly seems to be very tempting, but I'm too noob to even try to do such a dangerous thing.
Needless to say that I had to buy a new battery, but it wont happen the same mistake a second time. :)
I hope that this post might help some one in the future to prevent battery loss by ignorance.
Many thanks to you all.
Best regards,
António
sorry to hear that but you must NOT discharge the LIPO battery completely. if your charging station doesnt have storage charge then just discharge it to half of the charge capacity to be on the safe side.
Just to straighten out some figures.
The damage point for a LiPo cell is 2.5V, below which you have damaged the cell beyond recovery. (but this does depend on brand of cell, big subject, Google is your friend here)
A LiPo cell has no useful capacity below 3V, so the rated voltage range is 4.2V fully charged to 3V flat, but 3V is still above the damage point.
LiPo's should be stored long term at 30% capacity, that is the function of the Storage mode in some chargers. When you purchase a new LiPo you will find it at roughly 30% charge.
Put a multimeter on the individual cell connections in the balance plug, and you will be able to see the voltage of each cell, this will make it clear which ones have died.
If it won't charge with your charger, as others have said, fully discharge and dispose of according to the manufacturers instructions.
Regards,
Richard
Antonio, as already mentioned complete discharge has caused 2 cells to go less than the recommended voltage.
The "best" thing to do is to discard batteries. It is considered not safe to use anymore. It could damage your model / cause personal injury / if you use it.
Usually the charger has a mode called "STORAGE" which will charge/discharge to a voltage to store safely your LiPos.
Also buy a LiPo low voltage alarm : http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...
plenty of data about LiPo...maybe u start her,RC groups is very good place for all your questions.... http://www.rcgroups.com/forums/showthread.php?t=209187
...when u want to store battery u discharge them to 3,8 volts per cel,so13,2 V in your case..u can throw away those batts before they make fire.....when u fly its best never to discarge them belov 3,5 per cell...3,3 is minimum....also charge them with 1C...that way will last longer...few years
Good caution to all on LiPo batteries. Never discharge them completely or let them fall below 3 volts per cell. If they do, then they are caput and will never charge up again. They should actually be stored charged. The self discharge rate is low, but you need to keep them charged.