Battery charging question

[Casa Escarlata Robles Too]

Vic I looked at the Renogy DC to DC charger.
Would that be instead of the Isolator?
Frank

 

[Vic Harder]

Frank, any DC-DC charger will replace the isolator, and/or rather make the isolator inoperable. This is a downside of the DC-DC charger as it won't allow the solar panels to charge the truck battery. (although rando has posted a workaround using a relay and switch that bypass the DC-DC charger if wanted).

The Renogy requires that you add some more smaller wires (signalling that the truck is running, for example). The Victron is smart enough to not need any other wires than what you have.

 

[Casa Escarlata Robles Too]

Thanks Vic for taking time to give some info.
Not sure what I'll do yet.
My work around is to just run the fridge on propane while on the road.

My use of the 3 way is basically as a freezer.Starting a trip with it full of
whatever we need of frozen plus some containers of frozen water.
That method works for weeks on a trip.
The Truckfridge is our daily reefer unit.

Vic what actually does the BlueSea 7600 unit do and or replace?
Frank

 

[Vic Harder]

Vic what actually does the BlueSea 7600 unit do and or replace?
Frank

The BlueSea 76xx replaces the factory Sure Power 1314a

 

[Casa Escarlata Robles Too]

Vic does that BlueSea 76xx work the same as the Isolator
that replaced the Surepower1314?

Will the BlueSea 76xx solve the charging issue ?
Or do I still need a DC DC charger?

Sorry to keep asking maybe the same question.
I am just looking for an easy fix.

Thanks for all your advice.
Frank

 

[Vic Harder]

Yes, your AOPEC isolator does the same thing as the SurePower and as the Blue Sea

IF you are going to get the DC-DC charger you do NOT need any isolator at all

EASY in your case would be a victron orion. Less wiring for sure.

 

[Casa Escarlata Robles Too]

Thanks Vic.I appreciate all the info you have provided.
Frank

 

[Vic Harder]

Thanks Vic.I appreciate all the info you have provided.
Frank

Keep us posted...

 

[MidAtlantic]

Frank, any DC-DC charger will replace the isolator, and/or rather make the isolator inoperable. This is a downside of the DC-DC charger as it won't allow the solar panels to charge the truck battery. (although rando has posted a workaround using a relay and switch that bypass the DC-DC charger if wanted).

Vic,
Not sure what you mean about the D250SA not allowing charging by solar panels.
But, I do acknowledge the point about its 20A capacity.
Cheers.

 

[ntsqd]

Not so much that it won't allow charging by solar panels, but that it won't allow charging of the truck battery(ies) by the camper's solar panels. It is a one direction charging device, not a bi-directional device like the later dual sensing ACR/VSR's are.

Occurs to me that an older, single sensing ACR/VSR wired in parallel with the DC-DC converter and biased towards the truck batteries would allow automagical solar charging of the starting batteries while not interfering with the DC-DC converter's charging of the camper batteries.

The way that I see it, 40A from a ~120A rated alternator shouldn't be working it too hard.

 

[MidAtlantic]

Not so much that it won't allow charging by solar panels, but that it won't allow charging of the truck battery(ies) by the camper's solar panels. It is a one direction charging device, not a bi-directional device like the later dual sensing ACR/VSR's are.

Oops, didn't see that he said truck battery.

 

[Vic Harder]

Occurs to me that an older, single sensing ACR/VSR wired in parallel with the DC-DC converter and biased towards the truck batteries would allow automagical solar charging of the starting batteries while not interfering with the DC-DC converter's charging of the camper batteries.

That's intriguing. Too bad I chucked my old 1314a in the garbage a while back.....

 

[rando]

You would want to be a little careful with putting an isolator in parallel with the DC-DC charger. With it activated, it would be shorting the output of the DC-DC back to the input of the DC-DC. If the voltage were to rise enough that the DC-DC thinks the alternator is running, it will switch on - I am not sure what would happen in that case, but a direct short between input and output is probably not a recommended configuration.

If you want to have bi-directional charging you need a double throw relay. That way it is either DC-DC or direct connection between the batteries, but not both.

 

[ntsqd]

Good point. I was making the assumption that the two systems would never normally try to operate at the same time. Mr. Murphy, being who he is and all......

If the DC-DC converter has any sort of function indicator it shouldn't be too difficult to create a simple interlock (relay in the ACR/VSR's ground ref wire) so that the ACR/VSR can't operate while the DC-DC converter is operating.