29 replies to this topic

[mhjackson123]

I have noticed that after I have charged my 92 Ah AGM house battery, my Victron BMV700 tells me that I am charging up the truck battery for a while... (I leave the camper switch off and there is still significant discharge). I would prefer that the truck be able to charge the camper battery, but not the reverse. Does this make sense. It seems as if the battery link cuts out around 12.75 V which is quite a bit less than the camper battery seems to charge up to 12.9 or 13.0 V.

Thanks in advance for any suggestions.

Edited by mhjackson123, 06 July 2018 - 10:00 PM.

[ckent323]

What Blue Sea device are you using?  Is it the Blue Sea BatteryLink model 7611?

[Hodakaguy]

The Blue Sea ACR is dual voltage sensing and will combine the battery banks if either battery starts receiving a charge.  I replaced my factory ACR with a M-ACR that allows full auto or manual control of the ACR. 

 

Here's a link to the Mod:  http://www.wanderthe...r/?hl=hodakaguy

 

Hodakaguy

[Vic Harder]

What's the problem with having your charge source charging both batteries?  I have the same ACR as Hodakaguy, and charge both batteries via shore, alternator or solar all the time.  

 

Or are you saying that when you disconnect your charge source (40W portable panel - if I read your other post aright) that the BMV shows the camper battery flowing current towards the truck battery?

[mhjackson123]

What Blue Sea device are you using?  Is it the Blue Sea BatteryLink model 7611?

yes. the 7611.

[mhjackson123]

What's the problem with having your charge source charging both batteries?  I have the same ACR as Hodakaguy, and charge both batteries via shore, alternator or solar all the time.  

 

Or are you saying that when you disconnect your charge source (40W portable panel - if I read your other post aright) that the BMV shows the camper battery flowing current towards the truck battery?

exactly. I am guessing that the truck battery does not charge to the same high voltage as the camper AGM one. It does not matter if I am using solar or a standard charger to charge the batteries, current always seems to flow to the  truck battery.

[mhjackson123]

The Blue Sea ACR is dual voltage sensing and will combine the battery banks if either battery starts receiving a charge.  I replaced my factory ACR with a M-ACR that allows full auto or manual control of the ACR. 

 

Here's a link to the Mod:  http://www.wanderthe...r/?hl=hodakaguy

 

Hodakaguy

 

Did you just put a switch in to switch out the original ACR Battery link (7611)? Or did you go to the full M-ACR unit? Can I mod the factory installed one to work? Or just live with a loss of a few Ah after charging...

[Hodakaguy]

Did you just put a switch in to switch out the original ACR Battery link (7611)? Or did you go to the full M-ACR unit? Can I mod the factory installed one to work? Or just live with a loss of a few Ah after charging...

If your running AGM batts in the camper ideally you would run a AGM in the truck as well, then set the solar charger for 14.2 volts and let it properly charge both the camper and truck batt.

You might just add a switch on the factory ACR that will interrupt the ground off the ACR. When you flip the switch and disconnect the ground the ACR won’t be able to sense voltage and should stay in the off state. When you want it back in auto just flip the switch and connect the ground again.

I swapped my factory ACR out for a M-ACR, I like the ability to keep it force combined for extra AH when camping. I’m running dual AGM batts in the truck as well.

If you want a one way unit with no voltage loss from the wiring then install a RedArc DC-DC charger. They are really slick and would give you exactly what you are looking for.

Hodakaguy

Edited by Hodakaguy, 07 July 2018 - 02:13 AM.

[Vic Harder]

Did you just put a switch in to switch out the original ACR Battery link (7611)? Or did you go to the full M-ACR unit? Can I mod the factory installed one to work? Or just live with a loss of a few Ah after charging...

Switch in the line is cheap and a good temp fix.  Current flowing back/forth between the two battery banks is not ideal.  Like Hodakaguy says, AGM's in both places largely solves the problem.

[mhjackson123]

Thanks Vic, I will look at putting in a switch which I can use to disconnect after I arrive at a site. I can look at replacing the truck battery with an AGM starting battery when it dies...