Batteries not draining more than 40% capacity?!?

[stickboy]

Recently built a new large quad and I timed my flight the other day and got a full 16 minutes on a 4s stopping at 14.8v exactly. Just threw the battery on the charger and the LED screen showed to have only charged 3111mAh when my battery is a 8000mAh. That';s not even 40%!

So dare I go off the 80% rule and keep flying past 16 minutes or should I just accept that my 8.0Ah battery is no better than my 5.0Ah?

And I';m using the 10C 8000mAh Multistar - don';t know if that makes a difference.

[Revs]

I suspect you were flying in cold weather? These MS lipo';s, or most low C lipo';s tbh, don';t seem to like it much. As long as the voltage doesn';t drop past 3.3v/cell min in flight and as long as it recovers to 3.8v/cell min after being stood a while after the flight, I say you were ok. I have my RTL set to activate at 14.0v, which seems fine.

Also, you are leaving it stood for a while after the flight before charging aren';t you?

[hoverfly]

And I';m using the 10C 8000mAh Multistar - don';t know if that makes a difference.

I think you will find  a 10 c battery';s voltage will drop considerably  under load. This would explain the residual high  off load reading. .Also as mentioned the temperature will have a negative effect on performance.
Try a 25 c or something like a Nanotec  pack, they have a sharper discharge curve. Unfortunately  they also will have a higher drain on the wallet. ::)

[Peaky]

Please delete

[Revs]

IMHO that battery should be grounded until you';ve decided the exact cause but it';s up to you of course.
I would hate to be reading this time next week where your saying you';ve had a loss and wished you hadn';t used a battery you was worried about.

There';s nothing unusual about what stickboy describes. I';ve got 3 of these, albeit 4000 4s ones, but they all behave like that in winter.

As I said, my tri it set to RTL when the battery hits 14.0v in flight. After it';s landed and disarmed it reads about 15.0v. In Summer I up the RTL voltage to 14.4v in flight as there';s less v-droop in warmer weather.

[stickboy]

I suspect you were flying in cold weather? These MS lipo';s, or most low C lipo';s tbh, don';t seem to like it much. As long as the voltage doesn';t drop past 3.3v/cell min in flight and as long as it recovers to 3.8v/cell min after being stood a while after the flight, I say you were ok. I have my RTL set to activate at 14.0v, which seems fine.

Also, you are leaving it stood for a while after the flight before charging aren';t you?

Thank Revs, there';s so much mixed info on LiPo';s out there I';ve been afraid to go below 3.8v/cell. I might just have a half hour capable quad if I go down to 3.3v/cell.  ::)

Temp wise though, springs come early around my area so I';ve been flying on 60 degree F days. Didn';t charge back up until the next day and the initial voltage was just shy of 15.8v!

Try a 25 c or something like a Nanotec  pack, they have a sharper discharge curve. Unfortunately  they also will have a higher drain on the wallet. ::)

Sure thing, got a 4S 35C 5000mAh I';m about to go out and compare. Using a new quad with 390kv motors, but on my last build I';ve been surprised how little difference I get with the extra 3000mAh from the 10C MS.

[Revs]

I would take it to 3.5v/s in flight first and see how it is after landing. If it goes up to say 4.0v/s once disarmed then maybe go a little further, but be careful. Just bare in mind; if your battery is getting low, don';t be too aggressive on the throttle.