Hey I run 10k MAH 6 cell batteries and everyone I talk to has a different theory on what to run your rig to while under load. Is there any definite answer to this question? I know a static battery should be ran to 3.7 volts per cell before damage. While in the air I run to 21.2 volts and land but it says I still have 40-50 percent of the battery left and I am trying to achieve the 20 percent rule but it doesnt seem to happen without going below 21 volts? Any thoughts or is it okay to run below 21 volts?
Lipo under load?
- Thread starter Matto822
- Start date
Hey Matt,
From my experiences and asking similar questions, your battery(s) should stabilize at or above 3.7 per cell upon removing the load to avoid potential damage to them.
Everytime I fly mine and put them back on the charger, If my 6 cells are at 3.7+- per cell, my charger tells me I've got 20% remaining approximately.
If unloaded your battery says 3.7 per cell, obviously it's lower than that under load but you never want to fly lower than 3.2V per cell under load or 19.2V total. If you're using telemetry you should have a visual of your voltage.
Lower than 3.2V per cell and you risk batteries,aircraft and whatever you're flying around.
This is just one way to know.
It's best to know how much you put back in to full charge, then with simple math you can get an idea of what your flight times should be to be safe as well.
I inadvertantly left a small video lipo plugged in once and it drained all the way down to 2.5V per cell before i noticed. It got a little puffy but it's still useable. that's when I discovered that 3.0V per cell isnt the same as "fully drained" but keep things above 3.2V per cell at all times and you should be ok.
So basically: never go under 3.2V per cell loaded and try to keep it above 3.7V per cell unloaded. Make sense?
If your'e using voltage protection on your FC, keep your lowest threshold above 19.2 to keep things safe. 19.8V (3.3V PC) 20.4V (3.4V PC)
If you use balance port voltage alarms, I keep mine at 3.6V. For some reason they never read the same as loaded remaining voltage but the audible alert is enough to keep me paying attention to other methods of voltage tracking.
From my experiences and asking similar questions, your battery(s) should stabilize at or above 3.7 per cell upon removing the load to avoid potential damage to them.
Everytime I fly mine and put them back on the charger, If my 6 cells are at 3.7+- per cell, my charger tells me I've got 20% remaining approximately.
If unloaded your battery says 3.7 per cell, obviously it's lower than that under load but you never want to fly lower than 3.2V per cell under load or 19.2V total. If you're using telemetry you should have a visual of your voltage.
Lower than 3.2V per cell and you risk batteries,aircraft and whatever you're flying around.
This is just one way to know.
It's best to know how much you put back in to full charge, then with simple math you can get an idea of what your flight times should be to be safe as well.
I inadvertantly left a small video lipo plugged in once and it drained all the way down to 2.5V per cell before i noticed. It got a little puffy but it's still useable. that's when I discovered that 3.0V per cell isnt the same as "fully drained" but keep things above 3.2V per cell at all times and you should be ok.
So basically: never go under 3.2V per cell loaded and try to keep it above 3.7V per cell unloaded. Make sense?
If your'e using voltage protection on your FC, keep your lowest threshold above 19.2 to keep things safe. 19.8V (3.3V PC) 20.4V (3.4V PC)
If you use balance port voltage alarms, I keep mine at 3.6V. For some reason they never read the same as loaded remaining voltage but the audible alert is enough to keep me paying attention to other methods of voltage tracking.
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Thank you it does make sense. I was flying to around 21.2 I guess I can go a bit lower though. I do make sure all batteries stabilize at 3.7 or higher. Thanks for the post!
What voltage do you normally fly your 6 cell units to? btw I only fly by my voltage. I never really set timers because I always run two batteries and if something happened to the first I wouldnt know by the timer. I think voltage is the only way to fly and safest.
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I watch my iOSD voltage like a hawk and when I see my voltage around 19.8 I'm typically heading home. I keep my balance port voltage alarms at 3.6 and it gives me a pretty good heads up but they arent as trustworthy as telemetry and also knowing what you can typically get from your batteries safely. I also have a timer set on my transmitter to beep at me around 9 minutes. I consistently get 10 minutes out a loaded s800 and I'm over gross. My batteries always stabilize at 3.7+
I pushed it once this winter and got close to 13 minutes because my telemetry voltage looked good but when I put them back on the charger they were down around 10%. OOPS. probably decreased their life a bit there. That's why it's good to have standards and don't exceed them because you never know what to trust.
I don't use the voltage protection because I feel that its only useful for a multirotor airframe with no load (gimbal, camera). These suckers drop like a rock when heavy if it hits that pre-set lower limit.
In contrast, my un-weighted F550 gently descends when it hits the lower voltage protection limit.
If you are running your batteries in parallel then they are draining equally so you would have a rough idea by a timer, keep that in mind but if you had an alarm on a balance port you'd really know something was amiss when 5 minutes into a flight it's screaming at you. I'd recommend a quality one, the ones I have from HobbyKing are kinda junky. I landed tonight and it had voltages all over the place for my cells from 3.5 - 3.8. I plugged in another one and it gave me much more normal readings around 3.78. crazy
You're flying exactly like I did before i understood the capabilities. You're getting about 5-6 minutes I'd guess and youre probably stabilizing at landing between 3.78 and 3.83. What are you flying btw?
Look on the bright side, you're being really safe and conservative
I pushed it once this winter and got close to 13 minutes because my telemetry voltage looked good but when I put them back on the charger they were down around 10%. OOPS. probably decreased their life a bit there. That's why it's good to have standards and don't exceed them because you never know what to trust.
I don't use the voltage protection because I feel that its only useful for a multirotor airframe with no load (gimbal, camera). These suckers drop like a rock when heavy if it hits that pre-set lower limit.
In contrast, my un-weighted F550 gently descends when it hits the lower voltage protection limit.
If you are running your batteries in parallel then they are draining equally so you would have a rough idea by a timer, keep that in mind but if you had an alarm on a balance port you'd really know something was amiss when 5 minutes into a flight it's screaming at you. I'd recommend a quality one, the ones I have from HobbyKing are kinda junky. I landed tonight and it had voltages all over the place for my cells from 3.5 - 3.8. I plugged in another one and it gave me much more normal readings around 3.78. crazy
You're flying exactly like I did before i understood the capabilities. You're getting about 5-6 minutes I'd guess and youre probably stabilizing at landing between 3.78 and 3.83. What are you flying btw?
Look on the bright side, you're being really safe and conservative
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