Duration of a flight battery

[Kevin Brassington]

Hi folks,

Does anyone know how to calculate how long a flight battery should last for a given set up?

[Allan Bowker]

Try this thread Kevin.

Welcome to the forum.

[Paul Travis]

There's should and actually does !

i use telemetry to keep an eye on things

Quanum do an ok one from hobbyking saved many planes of mine

welcome also

paul

Edited By Paul Travis on 14/05/2013 22:17:51

[Biggles' Elder Brother - Moderator]

There is no definitive answer to that kevin - it depends on how you fly. If you blast round the sky on full throttle - not very long. If you stooge around gently a lot longer!

Do you have a watt meter? If so see how many amps you are pulling at full throttle and say 2/3 throttle - you can then work out a minimum time and a typical time figure from that data and the battery capacity.

Then set your timer for the typical time minus 1 min. Fly the plane, land when the alarm goes off and then see how much you have to put back into the battery. Adjust your timer accordingly - ie if you are only putting about 2/3 of the battery capacity back in - you can probably advance your timer by half a minute - maybe a minute. Then test again,

BEB

[john melia 1]

Just get one of these , they are brilliant , fly your model for a few mins put this across the battery and it will tell you what you have left in it , keep flying and testing till you are down to say 20% full , add the times up and there you go .

**LINK**

[Allan Bennett]

I agree that the trial-and-error method is most reliable, because your flying style is probably the most important factor, and you'd be surprised how far your amps drop when you stooge around at part-throttle.

But when picking a battery, or aiming for a duration for your first flight, just remember that the battery mAh tells you how long it should run at a certain amps level: For instance, a 2600mAh pack can deliver 2600mA (or 2.6A) for one hour, 5.2A for 1/2 hour, 26A for 1/10 hour (six minutes), and so on. Take about 75 or 80% of those durations to be on the safe side.

[Broken Prop]

I use the same type of meter as John M (mine came from Perkins) and it gives the percentage capacity left in the battery. I had not realised that the battery could be taken down to 20% though. I usually stop at 50%.

Is 20% capacity normal? If so this will extend the flight times on my motorised glider considerably!

Pete

[Olly P]

Hi Peter, 20% is quite normal.

[Broken Prop]

Thanks Olly!

i shall be tearing up the sky for much longer now I know that!

Pete