APM 2.6 hwvoltage

Hello !! I have a question about the hwvoltage that I can see into the MP status tab.
It indicates a value fluctuating between 4,5 and 4,6V , which seems to me too weak.
Verifying this voltage with a voltmeter ( i.e. on the APM’s gps connector) I confirm that
the measure is correct. However , my APM 2.6 is powered by a 3DR power module and I can measure 5,28V on its output , as on the APM PM input. I don’t understand why such a drop in voltage into the APM module , and if this weak hwvoltage value could be a problem during the flight. Thanks.

had same problem
5.2V from PM, and hwvoltage was like 4,6-4.9V
When powering from INPUT side the board voltage seems to be correct

Is it a 3DR APM or another make?
I “think” the non-3DR one’s do show a lower voltage on them, I know mine did but it flew perfectly.

It’s related to the crowbar protection circuit on the APM2.5. The older boards had a 500mA solid fuse, but near that 500mA ‘trip point’ it will drop 0.2-0.3v so you get a Vcc of 4.5V. The newer 2.6 boards have a 1000mA solid state fuse, which didn’t do that, so Vcc would be 4.8V-4.9V

more info here http://ardupilot.org/copter/docs/common-powering-the-apm2.html

Yes , it was delivered as a kit with the APM 2.6 and the GPS. But if your did it without problem , it is a good info for me. Thanks!.

Good info for me too. Thanks!.
Is it safe to fly APM with 4,80 4,9V ?