I’m using a li ion 2s battery on an AKRC BLheli 32 esc. I set it up as shown (excluding the low voltage protection), but my copter drops at 3.05V. Can I set something to use my li ion cells up to 2.5V?
My BATT_FS_LOW_ACT set to 0
Maybe that voltage is too low for the ESCs to operate at all, regardless of the low voltage protection settings. Remember they do have a small cheap CPU chip onboard that probably requires 3.3volts or 5volts to work.
Just a reminder:
Also check and adjust your voltage sensor calibration, at the lowest voltage you expect to encounter.
The other thing is to correctly set the failsafe voltages and actions in Ardupilot so as to avoid unexpected actions. For 2S Li Ion
BATT_ARM_VOLT,6.30
BATT_CRT_VOLT,6.00
BATT_LOW_VOLT,6.20
BATT_FS_CRT_ACT,1
BATT_FS_LOW_ACT,2 (or 3)
MOT_BAT_VOLT_MAX,8.20
MOT_BAT_VOLT_MIN,5.60
If the voltage levels give you failsafes too early, adjust BATT_LOW_TIMER before changing the voltage levels.
EDIT
The specs say “Input voltage: 2-5 cell liPo” so potentially a 2 cell Li Ion might not work.
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Thank you!
I think unfortunately the problem is hardware. The only real solution is where possible to override (by shorting) the 78L12 voltage regulator on the esc. This is for example possible on some HAKRC escs
I used a 2S Li-ion for awhile with an Aikon 4 in 1 and it worked down to those voltages.
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Do you remember the model? I would need 20x20mm.
Thank you
From RacedayQuads:
Aikon AK32PRO II 32bit 50A 2-6S 20x20 4in1 ESC
A bit expensive.
Note: If you are considering this Alberto I can test it again for sure next weekend if you like. I’m out of town at present. I had switched to a Lipo but it was flying on a Li-ion pack from one of my planes for awhile and I recall some fairly low pack voltages but not sure now how low.
Thanks Dave, maybe that’s too much for a small 3" 1106 4500kV.
I was also thinking of something very small 1/2S. Maybe 6/10A could be enough if I don’t have to fly freestyle racing.
Something like this:
I suppose if Blheli_S is OK with you and it supports the current requirement sure. Perhaps Bluejay will work on it.
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