Potential Renogy DC-DC and solar conflict?

[MisterB]

This was copied from another forum (not Motorhome specific)

It's discussing Renogy DC- DC charger. The comment re solar seems quite interesting. Anyone had a similar 'experience'? Is the comment correct?
I recently fitted a Renogy DC-DC and was surprised I wasn't getting the full charge last time out.


Found a few things with mine

- if you have solar connected, regardless how little current is coming in, then the charger will only take a max of 25amps from the alternator when it’s running. If you don’t have solar, it will take 50amps from the alternator when it is running.

So for the last part, added a relay on my solar cables that disconnect them from the charger when the car is running. That way whenever I am driving, I get the full 50amp charging.

 

[Lenny HB]

There have been quite a few posts about it.
Better to buy seperate units then if one fails you haven't lost all your charging.

 

[MisterB]

There have been quite a few posts about it.
Better to buy seperate units then if one fails you haven't lost all your charging.

Good point. I wonder if it's only applicable to the Renogy inverter and combined MPPT units?

 

[autorouter]

Yes, several on here have found that 'feature' in the Renogy DC-DC charger/solar controller. The answer, as stated, is to fit a cutoff relay in the solar feed that cuts it off when the engine is running.