Dynon EMS, strange behavier?

[Pilottonny]

After some testing and playing with the new installed avionics I needed to top-up the batteries. To be able to monitor the charging and check if the Dynon EMS was working correctly, I connected the battery charger to the alternator side of the AMP-Shunt (alternator not connected yet!).

However, the current on the Dynon EMS goes up and down from 0 to 18 Amp. continuesly, while the Charger shows a steady 8 Amps. After a while, the voltage has gone up a bit, the current keeps going up and down, but now from 1 to 12 Amps. The charger still shows 8 Amps steady.

Why does it do this? Any ideas? Thanks in advance for your reply.

Kind regards, Tonny.

 

[Dynon]

It may be that your charger is a PWM charger- it may be charging the battery by pulsing ~20A into it, then going to 0 for a while, then ~20A again. This is a fine (and efficient) way to charge a battery off the mains.

Since the charger knows it works like this, it can do averaging to show you 8A. The EMS assumes you have a normal system with an alternator, and doesn't average as much.

I wouldn't worry about this behavior. It sounds like everything is working fine.

 

[Pilottonny]

Appprox 1 hour to reply. Wow!

Wow! Just over an hour, on a sunday and reply from Dynon! Great service! I guess I will forget about this, till I "start-er-up" for the first time, with the alternator running and hope to see everything is OK.

Thanks for the quick reply.

Regards, Tonny