Aviator936
Member
Hey i have swollen batteries and ive been charging them at 1.1 amps when the highest is 2.2. I cant think of what id making them swell!!!
So upset
- Thread starter Aviator936
- Start date
Ketchup
4s mini mustang
The charging process isn't the only thing that can puff a lipo. Discharging it too fast, storing it for long periods of time fully charged or discharged, and discharging it too much are some other examples of how you can puff them.
When you say that "the highest is 2.2" what do you mean by that? Is this a 2200 pack where 2.2 amps is 1C, or is the capacity different?
I really doubt your problem is caused by charging too fast either way, so you should check for some other things:
Do you storage charge the batteries before storing them?
Have you made sure that your charger is charging to 4.2 volts per cell and not any higher?
How much do you discharge them? 3.0 volts is the absolute minimum for a lipo, but I typically don't even let mine get below 3.7.
What is the capacity and C rating and how many amps are you trying to pull from it?
When you say that "the highest is 2.2" what do you mean by that? Is this a 2200 pack where 2.2 amps is 1C, or is the capacity different?
I really doubt your problem is caused by charging too fast either way, so you should check for some other things:
Do you storage charge the batteries before storing them?
Have you made sure that your charger is charging to 4.2 volts per cell and not any higher?
How much do you discharge them? 3.0 volts is the absolute minimum for a lipo, but I typically don't even let mine get below 3.7.
What is the capacity and C rating and how many amps are you trying to pull from it?
Aviator936
Member
Yes so it was 2200 lipo pack. Its never been below 3.8 volts, and i did storage discharge the lipo before it went into storage for 3 weeks
Bifi.baarlo
Well-known member
You probably discharged the battery with to much amps, wich brand, type and c-rate lipo is it?
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M
MCNC
Guest
Same here a Gens Ace 1800 used twice . However it spent a week in a tree...
SSgt Duramax
Junior Member
I had a couple of batteries that died soon after out of the box. Sound like yours got discharged too much.
I just got my heli out after 8 years and those batteries were trashed (over discharged) and I puffed up another one because I wanted to try my rustler on 3S when I first got it, and all I had was plane batteries, so I stuck one in there and it puffed up. Thing won't hold a charge now.
The only other batteries I have killed were due to impact.
I just got my heli out after 8 years and those batteries were trashed (over discharged) and I puffed up another one because I wanted to try my rustler on 3S when I first got it, and all I had was plane batteries, so I stuck one in there and it puffed up. Thing won't hold a charge now.
The only other batteries I have killed were due to impact.
quorneng
Master member
I presume this was at the battery at rest after flying. The important bit is what did the cell voltage fall to when it was under load. You need fancy on board telemetry to find this out but 3.8 V would suggest the battery had been taken closer to 3.3 V under load than you might think.
Are you balance charging and are all the cells at exactly 4.20 V when the charger cuts out?
If the cells are much different at full charge it is quite likely that the weaker cell will become significantly discharged, and thus damaged, whilst the other cells are fine.
are you saying that batteries should be stored when showing 3.8v under load?
quorneng
Master member
No.
3.8V/cell no load.
It is also important they are all at the same voltage (to within 0.02 V) rather than just a battery voltage of 11.4 V for a 3s.
LiPo do discharge slowly in storage so if one was say 3.4 V and the others at 4 V it is possible the low cell could become damaged if stored for a few months over winter.
3.8V/cell no load.
It is also important they are all at the same voltage (to within 0.02 V) rather than just a battery voltage of 11.4 V for a 3s.
LiPo do discharge slowly in storage so if one was say 3.4 V and the others at 4 V it is possible the low cell could become damaged if stored for a few months over winter.
quorneng
Master member
The important thing is to initially fly for short time and check the battery cell voltages on landing. From that you can get an idea of how much longer is appropriate.
It is a good idea to keep checking the cell voltages anyway as it will indicate if one or more are getting weaker.
I try to arrange my flight times so that at the check the cells are not below storage level, 3.85V . It does mean I am using only about 40% of the maximum possible capacity but apart from being 'kind' to the LiPo it also means my flight times do alter much as the battery capacity degrades over time.
If a 'normal' flight time ends with 'at rest' cell voltages towards 3.3 V then the battery is at the end of its life in that application.
It works for me.
It is a good idea to keep checking the cell voltages anyway as it will indicate if one or more are getting weaker.
I try to arrange my flight times so that at the check the cells are not below storage level, 3.85V . It does mean I am using only about 40% of the maximum possible capacity but apart from being 'kind' to the LiPo it also means my flight times do alter much as the battery capacity degrades over time.
If a 'normal' flight time ends with 'at rest' cell voltages towards 3.3 V then the battery is at the end of its life in that application.
It works for me.
thank you,
i have telemetry on my umx turbo timber. i have learned (depending on the battery) that the voltage in flight varies with motor speed.
i usually fly until my 2s battery is down around 6.8 -7.0 volts. then, after i land, it is around 7.6 or even if i just slow way down and wait for the report, it will give me a similar reading to after landing.
am i damaging the batteries doing this?
i have telemetry on my umx turbo timber. i have learned (depending on the battery) that the voltage in flight varies with motor speed.
i usually fly until my 2s battery is down around 6.8 -7.0 volts. then, after i land, it is around 7.6 or even if i just slow way down and wait for the report, it will give me a similar reading to after landing.
am i damaging the batteries doing this?
Taildragger
Legendary member
if you don't want fancy telementry then these are helpful for the first few few flights of a plane when set with an alarm
https://store.flitetest.com/battery-checker-alarm-1-8s/
https://store.flitetest.com/battery-checker-alarm-1-8s/
Taildragger
Legendary member
set the alarm to a voltage you don't want it to go under load, then leave in the plane in flight. if the alarm goes off you know its going under that voltage with load
Piotrsko
Master member
Could do it the traditional old fogey way: hold it in your hand or attach it to something solid, being mindful of sharp spinney things, power it up and hang on until it beeps. Look at clock for how long. Since the prop is less efficient standing still it will use less power flying
