DCC50S + solar + mains charing

[Mwcard]

I contacted Renogy to see if the DCC50S is compatible with a mains battery charger (which I already have installed - looking to add the DCC50S + solar panel)

I got this response:
The DCC50S won't be able to detect if a battery is also being charged through another source hence we don't recommend using it at the same time with any other chargers as the battery may become overcharged. This means that you will need to disconnect your mains battery charger if the battery is being charged by the DCC50S.

How have people got round this before? It's suggesting that if you were able to isolate the solar panel when hooked up to mains then this would be ok or have I misunderstood?

Cheers
Matt

 

[Dellmassive]

Renogy is being over cautious...

All smart charges monitor the battery voltage as part of the charge profile...

Most lithium have a BMS that deals with charge voltage and disconnect the battery.

Basically if you have all three connected. EHU.dc-dc. solar .. they will all work stand alone and attempt to raise the battery voltage to the level as set in its profile.

 

[Dellmassive]

The dc50s is designed to have engine and solar simultaneously already. Adding the EHU smart charger in parallel is not a problem.

 

[CJW]

There’s only one scenario I can see where having the EHU charger running at the same time as a DCC50S source is even possible, which is when on EHU with solar. I put an isolator in for solar so that can be switched off when driving (touring) to get the full 50A from the alternator. The same isolator could be thrown to avoid EHU and solar working together but, as @Dellmassive says, it wouldn’t bother me to run both for the reasons above.

 

[Mwcard]

Thanks guys. I did wonder if it was an over-cautious default position that Renogy can't recommend anything other than what the unit is designed for (DC-DC/Solar). Usually not on EHU for more than 12 hours anyway, which is usually overnight, where there is no solar and engine not running so its not often, if ever, that all 3 will be trying to charge the battery at the same time anyway.

I think having an isolator for the solar is probably good practice but I'll think about the practicalities of that during the install.

 

[Dellmassive]

The Dc50s has a feature were it's 50A..

But will split 25/25A as soon as it sees a glimpse of solar...

So some people fit a solar isolation switch to enable the full 50A power from the engine when needed.

Then switch solar back on after.

Without a switch you will only have 25A max from engine.

 

[CJW]

If it’s any help, I put my isolator near the battery, under the driver’s seat and easily accessible from the open front. One isolator is the electrical load (lights etc) and another is between the solar panel and the DCC50S.

My understanding of the DCC50S is that it should never be connected to solar without the leisure battery being connected so if you ever have to disconnect the battery during the day, then an isolator between the panel and the DCC50S is a good idea and the (now) third good reason (in my mind) to put an isolator in.