Battery Autonomy - Time flight

Dear all,

I’m facing an issue and wondering why my Battery (6s 12000mAh) supposed to provide a 35mn flight time just gives 20mn (Out of Battery)… Then, Check voltage after landing… 23.24v (50%).

My Lipo is pretty brand new but…

Please see the pics in attachement

Thank you for your help


Have a look at the battery voltage in your log from the copter.
You are most likely experiencing voltage sag under load.
By the time you measure the voltage on the battery it has had time to recover.
What’s the current draw of the copter? (again from the log)
What is the C rating of the battery?
What voltage do you have the battery failsafe set to?

Battery time will decrease when the temperature is falling, especially in high altitude .
and will recove when the temperature raise.

Hi Mike,

Thank you for your help, please find down under answers to your questions.

C Rating is:10
Battery Voltage to failsafe was 22.2 - 1000mAh
Curr. Volt (Min.:2167; Max.: 2268; Mean: 2238)
Curr. Curr ((Min.:0; Max.: 3104; Mean: 1151)



Hi Eric

Thank you for your post, I am located in western australia and temperature this morning was 25C


I never use battery failsafe via Mavlink; the power modules I’ve used don’t read correctly under load. Instead, I use the FLVSS battery monitors that are available for the Taranis which plug in directly to the balance plug and provide a way to monitor cell voltage real-time. I also have one of the current sensors that use the smart port as well. I have an alarm that warns me when I’m down to 3.7v per cell. In flight the voltage reading is a little different than when at rest.

And a 10C battery might be borderline. They sag terribly under load. All the 6S batteries I’m using on my Hex (5 kilo rig) are 25C or better. Less sag.

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Thank you BigTulsa, That was actually my primar asumption about 10C battery. I actually use Futaba but I’m actually wondering to invest into Taranis but l have no idea how reliable it is

Dear all

Please see pics in attachment, I guess my time electricity sag is mainly due to 23v and not 22.2v draw combined with my Lipo 6s battery Capacity reduced ~18% (10000mAH) - I = Q/T (Peukert effect)

Last but not least… Specs published by Tarot regarding effciency are not correct for about 10% higher than reality :frowning:

Thank you in advance for your comment

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