Battery charging after running battery to low end of safe voltage

[DucktileMedia]

I bought one of these Hobbyking voltage monitors. Up until now i have put many cycles on my batteries/charger and they always charge to exactly 12.60 volts for my 3s batteries. After today though my batteries only charged to 12.12. Only difference was that I ran the battery until the alarm went off. I then immediately landed. So the question is, did I ruin my battery by running it a little lower than I normally do? I usually run them to about 11.7 or so volts.

 

[Tahoe Ed]

How many mAh do you put back in? I try for 80% of capacity but sometimes I run down to 90%. I have not had a problem with recharging back to the 12.6.

 

[DucktileMedia]

i charge my 5500mah batteries at 5amps, the max it goes. My point is that I have never had any problems until i decided to stop flying when the alarm went off. I think I probably did some damage to the battery running it to the 3.3 volts the alarm sounds at. Great!

 

[Droider]

I have unintentionally run my overlanders way lower than that when I did not have my battery alarm on and they always recover. Have you tried running them for a couple of mins then doing a balancing charge?

DAve

 

[hexa]

yep sounds like the lipo needs a re balanced charge.

 

[DucktileMedia]

I have a very nice charger that I assumed is always balancing them. Is there a step I am missing? Maybe a discharge, then recharge? Just seems weird. I think from here out I will just rely on my timer more than the alarm. I was just eager to see when it sounded off. Thanks for your input.

 

[Bartman]

yuri,
i've been using those battery monitors for a while now and they actually alarm at a higher voltage than the low voltage setting recommended by mikrokopter. as i understand it, charging at the max rate will shorten the life of the batteries more quickly than discharging them to some minimal level. like others have said, i've gone to near nothing by mistake a few times and the cells went right back up to 100% afterwards.
bart

 

[DucktileMedia]

this is the charger I am using and so far has been great. I would think charging a 5500mah battery at 5ah is appropriate.

http://www.hobbypartz.com/skychb6chdup.html

 

[thepelell]

yuri,
i've been using those battery monitors for a while now and they actually alarm at a higher voltage than the low voltage setting recommended by mikrokopter. as i understand it, charging at the max rate will shorten the life of the batteries more quickly than discharging them to some minimal level. like others have said, i've gone to near nothing by mistake a few times and the cells went right back up to 100% afterwards.
bart

that's interesting.. i've gone down to 8v on a 4s pack, and my charger refuses to charge them.. keeps saying "Low Voltage" ... i thought there was no way to save them...

 

[wayno complaino]

that's interesting.. i've gone down to 8v on a 4s pack, and my charger refuses to charge them.. keeps saying "Low Voltage" ... i thought there was no way to save them...

Sometimes using the NimH setting to charge will rescue over discharged LiPo's. Just be careful.

 

[ZAxis]

Sometimes using the NimH setting to charge will rescue over discharged LiPo's. Just be careful.

I have tried this but no longer do so after one LiPo swelled .... smoked and then burst into flames ... big violent flames. Just luck that I took it outside while smoking otherwise it would have been fun explaining it to the insurance company after the fire brigade left.

 

[wayno complaino]

I have tried this but no longer do so after one LiPo swelled .... smoked and then burst into flames ... big violent flames. Just luck that I took it outside while smoking otherwise it would have been fun explaining it to the insurance company after the fire brigade left.

Are you refering to the battery that had sat outside for days when you lost your hexa? Wasnt it already blown and completely dead ;-)

 

[Jzquad]

Rule of thumb about batteries is to never discharge them more than 80% of their total capacity and regardless of the cell count, if you go lower than 3 volts in any cell, you might have ruin the battery.
I usually charge them at low rate, I have 20 chargers from hobby king, so I put 20 batteries to charge at the same time at .5 amps. Yes, it takes longer to charge them, but if you have the luxury of "low rate" charging, that will extend the life of your batteries