lipo charging ?
- Thread starter turfRC
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
links, including eBay, Amazon, and others.
RCBro80
Active Member
3900 sounds like the capacity (mAh) added from your starting voltage to fully charged.
If each cell is at 4.2V, they're fully charged and I wouldn't worry about that.
If each cell is at 4.2V, they're fully charged and I wouldn't worry about that.
RCBro80
Active Member
I would suggest searching lipo use and care... There's a few important things to know and safety is key.
Always balance charge, to make sure every cell is charged to the same voltage.
Fully charged is 4.2V per cell. You NEVER want to let the cells go below 3V, most ESC's will cut off at around 3.5-3.6V (x however many cells you have). Don't leave batteries fully charged for longer than a day or 2, instead store them at 3.82V per cell (storage voltage) although its ok to leave them at, say, 3.6V for short periods (months could allow them to discharge too much, so you'd want to storage charge them in that case)
Always balance charge, to make sure every cell is charged to the same voltage.
Fully charged is 4.2V per cell. You NEVER want to let the cells go below 3V, most ESC's will cut off at around 3.5-3.6V (x however many cells you have). Don't leave batteries fully charged for longer than a day or 2, instead store them at 3.82V per cell (storage voltage) although its ok to leave them at, say, 3.6V for short periods (months could allow them to discharge too much, so you'd want to storage charge them in that case)
jkflow
TB RC Bashers
Lifetime Premium!
Premium Member
Excellence Award
Hospitality Award
Build Thread Contributor
This. 
Stop looking at the capacity meter, the voltage tells you everything.
Above 4.2V = house on fire
3.8V = always at this level unless you are charging and running your truck shortly thereafter
Below = 3.5V degrading quickly
Below 3V = dead lipo, discharge to zero, dispose and buy a new one
Stop looking at the capacity meter, the voltage tells you everything.
Above 4.2V = house on fire
3.8V = always at this level unless you are charging and running your truck shortly thereafter
Below = 3.5V degrading quickly
Below 3V = dead lipo, discharge to zero, dispose and buy a new one
RCBro80
Active Member
So, I recently had a cell dip below 3V (I think my balance lead was off by 1 pin in the voltage alarm, and when one cell gets low, it drops fast).This.
Stop looking at the capacity meter, the voltage tells you everything.
Above 4.2V = house on fire
3.8V = always at this level unless you are charging and running your truck shortly thereafter
Below = 3.5V degrading quickly
Below 3V = dead lipo, discharge to zero, dispose and buy a new one
My charger is able to recover cells in this state (although, I assume there's a lower limit beyond which it won't) by charging very slowly (0.15A) until the cell voltage is above 3.5V.
I understand that I've likely done some permanent damage to the battery, but I still plan to use it. In fact, the cell this happened to is only reported as 4mΩ.
Here's an interesting link about this: https://www.instructables.com/Restoring-over-discharged-LiPo-Lithium-Polymer-bat/
Last edited:
- Messages
- 1,789
- Reaction score
- 2,945
- Location
- In the stix…NC Mtns
- Arrma RC's
- Kraton 8S
- Kraton EXB
- Mojave
- Senton 3s
You, sir , have better than average knowledge of this topic. I do thank you and jkflow (plus others) for sharing your know how.
That being said, The last thing anyone needs is a battery to go WAY SOUTH on us, (catch on fire, etc)...... so..... myself, being relative noob to much of this, I will stick to the 3V and below = dead, discharge and discard, just for the safety factor.
I am in NO WAY challenging your know how or methods..... I am sure you are on top of all this, but a message for those out there who are not REALLY ON THE KNOW like these guys are, PLEASE FOLLOW THE ABOVE GUIDELINES!!!! BE SAFE...... go on YouTube and watch a video on LiPo fires...... it made me go and get metal ammo boxes and follow the above..... (just echoing your first comment above)
THANX you guys for sharing this info......other than being hit in the head by a Kraton 8S at top speed, battery care can be the most dangerous aspect of this hobby.....
RCBro80
Active Member
And don't charge them unattended!
jkflow
TB RC Bashers
Lifetime Premium!
Premium Member
Excellence Award
Hospitality Award
Build Thread Contributor
That is a good article!
I made the same mistake and discharged a Lipo to something like 2.8V and yes you can bring them back to life but despite semi-ok IR it has lost it's punch and compared to the other, exact same one, it's easily in the 70% range on capacity.
If you know what to do you can revive it but it's almost worthless. I store mine outside and do not worry about fires, they don't explode just because you over-discharge but they are crappy at best. I use it now for stuff at home, just to power on, and change ESC settings etc.
The Lipo is forever chemically altered, that is permanent. I did have a 0V Lipo once and tried as well but nothing helped. All that experimenting was done outside on concrete. Don't be tempted to try this inside.
I made the same mistake and discharged a Lipo to something like 2.8V and yes you can bring them back to life but despite semi-ok IR it has lost it's punch and compared to the other, exact same one, it's easily in the 70% range on capacity.
If you know what to do you can revive it but it's almost worthless. I store mine outside and do not worry about fires, they don't explode just because you over-discharge but they are crappy at best. I use it now for stuff at home, just to power on, and change ESC settings etc.
The Lipo is forever chemically altered, that is permanent. I did have a 0V Lipo once and tried as well but nothing helped. All that experimenting was done outside on concrete. Don't be tempted to try this inside.
