Adding onboard charger to an existing VSR system...?

[GTBRMC]

Looking to install a dual bank, onboard charger. Have an existing, circa 2009 BEP VSR that dealer installed (somewhat cockeyed) when I took delivery.

Question: How do I wire in a dual bank smart charger so that it works as designed and will not harm the boat or the batteries?

Not the best of pix, but this shows the VSR... It is a 125 amp, dual sense VSR (does not say "digital" - not sure if it is or is not):

 

[JetPowered]

You would want to wire the charger on the battery side of the switches or VSR. In my case I wired directly to the lugs on the battery terminals. You want the charger to charge each bank even if it is isolated or off.

 

[tdonoughue]

I think there is more to that. I actually have the same question (though I have the Sea Blue ACR). The issue is that when there is charge on the batteries, the ACR/VSR shorts out the batteries to each other. The ACR/VSR cannot tell whether that is from the magnito or from a charger. So, I think, that defeats the 'dual battery' part of the charger.

Right?

So I think you need to connect up something to lock out the ACR/VSR to prevent it from hooking the batteries together while charging. I wrote to Sea Blue and they said to hook your Sea Blue charger ACR connection to the ACR. Thanks guys. What if I don't have a Sea Blue charger? <sigh>

 

[JetPowered]

I would think you would want the batteries to be completely isolated from the VSR. Ideally there should be a disconnect as the last part of the circuit just before the battery. The VSR should be completely disconnected. Best thing to do is test with a multimeter and see what voltage is going where when charging.

 

[David Analog]

It doesn't matter what brand of VSR you have or what brand of dual bank charger you have.
The two battery banks need to be totally isolated while in storage so that they cannot be influenced by the voltage sensing relay/solenoid.
The most automated method is for an AC triggered relay (different from a DC triggered relay) to interrupt the VSR ground wire whenever AC is present for the battery charger.
Or, as a manual method, and if you have a dual-circuit-battery switch (different from the conventional dual battery switch) you can alter the VSR + Switch schematic priority so that when the switch is 'Off' it isolates the relay thereby isolating the two banks.

 

[jetboater4life]

It doesn't matter what brand of VSR you have or what brand of dual bank charger you have.
The two battery banks need to be totally isolated while in storage so that they cannot be influenced by the voltage sensing relay/solenoid.
The most automated method is for an AC triggered relay (different from a DC triggered relay) to interrupt the VSR ground wire whenever AC is present for the battery charger.
Or, as a manual method, and if you have a dual-circuit-battery switch (different from the conventional dual battery switch) you can alter the VSR + Switch schematic priority so that when the switch is 'Off' it isolates the relay thereby isolating the two banks.

I did the last thing that David mentions. When my switch is off the batteries are isolated and my dual bank charger charges each battery independently. @txav8r helped me with the wiring diagrams.

 

[GTBRMC]

I will do as a David suggests, but likely will wait until after boating season. I've spent far more time modding the boat this year than I intended - it looks as though I will have to do quite a bit of switch and wire relocating. I want to USE the boat sometimes, too. LOL!

I will pick up a dual bank onboard charger to take to and use at Shelbyville...I will just disconnect & reconnect cables a couple times that weekend. Maybe someone that has done this can show me their setup at Shelbyville.

Thanks to all for their input.

 

[Ronnie]

I just wired the two pairs of positive and negative leads from my dual bank charger to each battery separately and turn all the three switches (i.e., engine, house/accessories and combine/emergency) to off when the charger is operating. I haven't had any battery related issues in the almost four seasons I've had the charger configured like this.

 

[GTBRMC]

I just wired the two pairs of positive and negative leads from my dual bank charger to each battery separately and turn all the three switches (i.e., engine, house/accessories and combine/emergency) to off when the charger is operating. I haven't had any battery related issues in the almost four seasons I've had the charger configured like this.

I believe I will splice one of these https://www.bluesea.com/products/5510e/e-Series_Dual_Circuit_Battery_Switch into the positive wires that run between the batteries and the VSR switch and then wire the dual bank charger as you describe. Unless I have missed something, when I throw this switch, it will remove the positive legs of the boat & VSR from the positive legs of the two batteries. Note: other than the photo at top of this thread, I am going from memory on the wiring here.

I realize this will not be automatic, but I will only need to occasionally use the charger, anyway. Anyone have a better idea or know that my logic is flawed?

I am out of $$$, time, and - most importantly - wife's patience for any more mods this season, so this switch install will likely wait until this fall.

 

[jeremy0011]

I added a 120 volt relay that disconnects the neutral wire on the VSR. This disables the VSR and allows me to charge the batteries while still keeping the function of all the electronics/bilge pump.

 

[GTBRMC]

I added a 120 volt relay that disconnects the neutral wire on the VSR. This disables the VSR and allows me to charge the batteries while still keeping the function of all the electronics/bilge pump.

Can you provide brand & part number of the relay and a wiring diagram? Thanks.

 

[jeremy0011]

I can’t take credit for the original drawing but I added the relay to it. I can’t remember which relay I used but any 120v relay with a NC (Normally Closed) contact will work. Here is one I found on Amazon http://www.amazon.com/General-Purpo..._sim_60_1?ie=UTF8&refRID=1WZ5EGTH170JFR98NB57 . I installed the relay in a small plastic electrical box that I found at Home Depot. I also used the box as a junction box for the shore power and mounted it next to my 2 on-board chargers.

 

[GTBRMC]

I can’t take credit for the original drawing but I added the relay to it. I can’t remember which relay I used but any 120v relay with a NC (Normally Closed) contact will work. Here is one I found on Amazon http://www.amazon.com/General-Purpo..._sim_60_1?ie=UTF8&refRID=1WZ5EGTH170JFR98NB57 . I installed the relay in a small plastic electrical box that I found at Home Depot. I also used the box as a junction box for the shore power and mounted it next to my 2 on-board chargers.

I will digest that & see if I can apply something similar to my setup. Thank you - much appreciated!