• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

HELP, Battery won't charge

#1
Hi there, I think I over discharged my new 3cell 11.1V tattu battery, and now it won't charge. Any ideas on what how to try save it?
I measured it with my multi meter and the battery is at about 3.5 volts. thx
 

Ketchup

4s mini mustang
#2
The whole battery is 3.5 volts, or each cell? If it is each cell, then you might have over charged the battery, it might be okay, but you could have damaged it. If it is 3.5 volts as a whole, it is most likely dead.
 

FDS

Well-known member
#3
If you put it below 3.3v per cell then it’s damaged. You can recover them by using different settings on the charger but the chemistry will be permanently altered and it won’t last well. I would advise safe disposal and replacement.
Is the pack puffy and “bloated” in its wrapper?
To dispose of it safely you should connect a car tail light bulb to the main plug and leave it outside until it reads 0v. You can then recycle it or dispose of it however your country recommends.
A battery monitor that can read each cell voltage is a useful tool to have in your flight box. That way you can fly for 4-5 mins, land, then check the battery voltage. I have my TX timer set to go off around the time I hit 3.6v per cell to give me a little wiggle room. Fixed wing ESC’s also come set to pulse or dip the throttle if you hit 3.5v per cell to protect your battery. That’s why I avoid all the cheap Simonk ones on eBay, the firmware on those deliberately removes any battery protection as it was designed for quads.
 

cranialrectosis

Well-Known Member
Mentor
#4
Damaged lipos are dangerous. Search Youtube for 'lipo fire'. Don't keep damaged lipos in your home with your family.

If you have discharged it lower than 3.3v per cell, dispose of it safely per local regulations.

A $50 lipo isn't worth anyone's house.

Batteries Plus Bulbs recycles lipos for free!
 

Bricks

Well-known member
#5
I have recovered a few Lipos I have run to far down and they seem to be fine resistance has gone up some because of being stupid. If there is no puffing ( do at your own risk ) I will take another battery that is good and plug both main leads into my parallel charging board,, keep an eye on them usually will take about 10 minutes the dead battery will take enough charge for your charger to read enough voltage to start a normal charge. Normally a charger will not recognize a battery that is too low on voltage to start the charge sequence. I have batteries that are a few years old I have recovered this way.

Any one that dosen`t want to try to recover there battery from too low voltage I will pay shipping if it is a size I can use. Even if one bad cell and I have rebuilt many batteries not that hard.

No reason to add to landfills with a battery that may be perfectly good.
 
Last edited:

Merv

Well-known member
#6
I agree with everyone, this is a situation that requires a great deal of caution.

If you want to try and revive this battery, change it for 15- 20 minutes on the lead acid battery setting. Once it gets a charge, 9-10 v for 3S, that is 3v or so per cell, use the Lipo balance setting to finish.

One should never charge ANY Lipo battery unattended, DEFINATLY NOT THIS ONE. This battery will forever be suspect, CHARGE AT YOU OWN RISK.
 
Last edited:

speedbirdted

Well-known member
#7
If it's at 3.5v per cell, there should be no permanent damage. Your charger is the problem here - lipos only start to become damaged when discharged to below about 3.2v/cell. However, if it's at 3.5 volts total for the entire battery, she's toast. As others have said most lipo chargers will not bother to charge a battery that's this low. Doing some of the things mentioned above can sort of bring it back however this battery is always going to be a safety risk and the increased internal resistance is going to seriously hurt the performance of it. Potential fire damage is never worth it versus the replacement cost of the battery. You can dispose of it by connecting it to some sort of draw that results in a slow discharge like a few resistors or an LED, then submerge the battery in salt water until it's at 0 volts. People say that it's safe to then throw away lipos in the garbage like everything else after this is done but it is not, and taking it to a dedicated battery recycling center is always going to be the best option.
 

Ketchup

4s mini mustang
#8
The whole battery is 3.5 volts, or each cell? If it is each cell, then you might have over charged the battery, it might be okay, but you could have damaged it. If it is 3.5 volts as a whole, it is most likely dead.
Sorry, I misread 3.5 as 4.5. But yeah, you might not have damaged a battery, but still be careful with it.