feedback on battery/voltage limits setup?

schwett

Member
hi all: looking for some advice or confirmation here. my batteries (a pair of century 6S1P 5000mah 40C 22.2V 6S LiPo) were only taking about 2500mah per charge (according to the readout on the hitec x1), so i adjusted the voltage limits on my s800.

the copter is as follows:

DJI S800
DJI vibration absorber mounts
DJI folding compass mount
DJI bluetooth LED
DJI WKM
two century 6S1P batteries mounted symmetrically, connected with XT60 y-cable, the second on an additional DJI battery mount tray)
Nikon D810 on a simple fixed custom mount, with either 20mm f/1.8 or 35mm f/1.8 lens.​

takeoff weight is just about 6kg/13lb. the CG is dead in the middle front/back and left/right.

fully charged and just sitting on the ground, the assistant registered 25.3v. hovering a few feet in the air it was showing about 24.2V, but varying by ±.2V. is a voltage drop of 1.1V normal? seems a little high.

i adjusted the settings to the following
first level protection no load 22.5v, loss 1.1v. (loaded 21.4v)
second level projection no load 21.7v, loss 1.1v. (load 20.60v)​
first level is set to "LED Warning" and second level is "descending."

when the second level warning hit, i charged the batteries and the charger showed 3,948 MaH. 20.6V seems very low to have only then received 80% charge. is that normal?

finally, the charger is set for up to 6 amps, but only charges as 2.3 amps. it takes 1.5 hours to fully charge one battery, so 3 hours total. long time.

i have noticed that the century 6S1P is fairly heavy for the rated capacity - there are other batteries which have specs 25-30% better, so i might go to a different type of battery, even slightly lower capacity ones to save some weight. any comments on maxamps or thunderpower relative to the century, which i didn't personally choose?

thanks in advance for any advice! i've got in about 30 flights so far, flying 90% of the time on attitude. no catastrophic crashes. the main challenge has been unpredictable winds and maintaining control when the copter is too far away to really see which direction is which.
 

rilot

Member
The HiTec X1 is only a 50W charger so it doesn't matter what you set the charge rate to, it will only ever be able to do around 2A for 6S batteries. You need a much better charger.

As for the voltage limits, I have mine disabled and rely on the iOSD data and telemetry. Much more reliable than having the craft go in to an auto descend or something.
 

schwett

Member
The HiTec X1 is only a 50W charger so it doesn't matter what you set the charge rate to, it will only ever be able to do around 2A for 6S batteries. You need a much better charger.

As for the voltage limits, I have mine disabled and rely on the iOSD data and telemetry. Much more reliable than having the craft go in to an auto descend or something.
 

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