Naze (cleanflight 1.9) starts complaining about battery voltage too soon.

[pungbjoern]

I'll start getting (what I assume are) voltage warnings after only about 3 minutes of flight. When I set it down, my voltage is at 11.5, which is 3.8V per cell! I have the warning set to 3.5, and by the time I set it down, it's gotten to be a pretty insistent warning. Looking at my settings, I have minimum cell voltage set to 3.3 (default), and warning cell voltage set to 3.5 (default). The voltage scale is set to 110 (default). When I set it down, the batteries are not particularly warm, so it's not like they're actually drained but are reporting the wrong voltage (from what I can tell). Connecting them to the charger tells me 11.5V as well, so it's also not a discrepancy in the voltage monitoring circuit (in so far as they both return the same value).

Anybody know what I can do to fix this? I don't want to disable to voltage alarm and fly on a timer, but if the voltage alarm is simply wrong, there's little else I can do. It's also not just when I'm punching the throttle or something. I can be simply hovering, after an alarm beep, and hear the beep again.

Alternatively, could it be beeping for some other reason?

 

[pungbjoern]

It's the scale. 3.5 * 1.1 = 3.8. Alright, fixing that right now

 

[Ocean]

Voltage Sag

 

[pungbjoern]

Voltage Sag

Unlikely:

It's also not just when I'm punching the throttle or something. I can be simply hovering, after an alarm beep, and hear the beep again.

It's likely the voltage scale. I've set that down to 100 now. We'll see.

 

[Ocean]

Unlikely:



It's likely the voltage scale. I've set that down to 100 now. We'll see.

I agree, if it were voltage sag I would expect it to stop when you land...

 

[Cyberdactyl]

Voltage Sag

Yep, and very early beeping of a fairly low setting (if the battery is healthy) when pumping the throttle hard is an indicator the battery's c and mAh rating is likely too low for the craft.

 

[C0d3M0nk3y]

You can check the scale by looking at the voltage reported in the configurator and comparing it to the actual voltage.

 

[pungbjoern]

It turns out that lowering the voltage scale did not fix the problem. It turns out that the scale is applied to everything (surprise surprise), both measurements AND limits (making the scale all but useless). When I set the scale down to 100 (as opposed to 110), it would start complaining about low voltage almost immediately. I'll have to do some more testing to see what's up.

I ended up flying all of today on a timer. 5 minutes seems to be reasonable.

 

[pungbjoern]

You can check the scale by looking at the voltage reported in the configurator and comparing it to the actual voltage.

That's exactly what I did. The voltage when voltage scale was set to 110 matched in the flight controller and on my charger. However, setting the scale to 110 means that my limits are not 10% higher than they should be, because the scale seems to apply to everything. I've left the scale at 110 now, but set my limits to ~91% of where I want them, to get the correct effect. I'll see if that works correctly for my flight tomorrow.

 

[narcolepticltd]

Unless the alarm is constantly beeping, I'd say it's working exactly as it should and you're just bottoming out your voltage due to sag on the battery. If you're just hearing a chirp on maneuvers, that's the battery voltage dropping due to strain (but it comes right back once it rests for a few seconds).

 

[pungbjoern]

But it is constantly beeping. Even if I hover or set it down once it starts. It very quickly becomes incessant.
With the scale set to 100, the first battery I connected it started beeping from the moment I connected it.
I just charged a battery to full, and with the scale set to 110, it exactly matches my charger. This is good.
What's less good is that I now have to set my limits to (limit * 0.909) to have it actually be correct.