Low flight time on Eachine Racer 250 (cc3d)

Gos · « **on:** January 30, 2017, 09:17:06 am »

Hi everyone,

I am hoping that someone here is able to set me on the right track in figuring out a problem I got with my ER250 (cc3d flight controller).

The problem: I got very low flight time on my eachine racer 250, typically around 3 minutes in 0-5 degrees celcius.
Battery: 3 batteries all 3s 1500mah
Flight style: I fly in Rattitude mode, but I am mostly just cruising around and not stressing the motors at all. No flips or acrobatics of any kind (sort of when I find a nearby tree and topple to ground).
Blades: 2-blade stock props.

From the ER250-facebook group the users report they got flight time up to 10 minutes in similar or worse temperatures. I am starting to think this may be due to "bad PIDs" which stress the motor and drain power unnecessarily, but I do not know.

Can someone provide some tips and tricks in order to troubleshoot this issue further?

--Gos

TheOtherCliff · « **Reply #1 on:** January 30, 2017, 05:39:27 pm »

Do the motors get hot?

Export settings so you can get back to them if you want them.
If it is PIDs, you could multiply all the P, I, D by 0.75
It will get mushy and harder to fly, but you can see if that helps the flight time. If so, you need to retune.

ernstock · « **Reply #2 on:** January 30, 2017, 08:33:28 pm »

I'm wondering what means of judging flight time you are using.
Can you / do you take a voltage reading -5 mins (or more)after use ?

Gos · « **Reply #3 on:** January 31, 2017, 09:07:58 am »

>> Do the motors get hot?
No, not really. The drone does not feel hot at all to be honest.

>> If it is PIDs, you could multiply all the P, I, D by 0.75
Should I just multiply it by 0.75 regardless? There are no other considerations to take into account?

>> I'm wondering what means of judging flight time you are using. Can you / do you take a voltage reading -5 mins (or more)after use ?
I am using the onscreen display in my FPV goggles as well as a voltage monitor to get the voltage. The FPV goggles also includes a flight timer, so I can record flight time and voltage fairly accurate.
When I am flying and the voltage reads between 9.6-10.0 I land immediately - once I have landed and everything is turned off, the voltage is approx. 11.[0-5]

TheOtherCliff · « **Reply #4 on:** January 31, 2017, 06:04:21 pm »

Battery might be not as good as it was. Fly without GPS and see if time comes back up.
Reducing PIDs will make it mushier, but will fix it if it is PIDs. Try it to see if it helps.

hwh · « **Reply #5 on:** January 31, 2017, 08:52:25 pm »

If they're eachine batteries they may not have been very good to start with. The two that came with my racer250 both had very weak #2 cells. One died and that cell went to zero volts the first time it was connected to the charger. The seller replaced it with a different style battery and while it's #2 cell is a little off (a tenth of a volt or so lower than the others even after balance charging) it's still working. I only use it for the monitor, I've never used it for any high load use. The second original battery failed a few days after the first (#2 cell went to zero) after powering the little eachine fpv monitor for 10 minutes. The other cells were still showing almost full charge at the time.

ernstock · « **Reply #6 on:** January 31, 2017, 09:01:22 pm »

Yeah. As above , I fear batteries may be at fault.
Myself , on 3s. I would land when I started to see volts 10.6 -11 .