Wiring and Battery Addition

[jcb1977]

5) You can wire the battery and ACR 1 of two ways, per Blue Seas, I spoke with them at length. If you wire the ACR and the Batteries two the same two posts that is fine. You can also wire the ACR to the top posts and the batteries to the bottom posts, which takes the ACR out of play when you have the switch to off. Either way is fine and won't hurt anything.

@HangOutdoors with your multi bank charger, wouldn't you want the ACR on the load side of the switch instead of the battery side? That way when switch is off, batteries are completely independent of each other and have separate charging profiles? If ACR is on battery side, and a charge (either from engine or from battery charger) is present (regardless of battery switch position), won't the ACR close and combine the batteries?

after researching various threads on battery setup's, I came to the conclusion with my 2 bank charger directly wired to each battery, I should have the ACR on the load side. Just wanting to understand why you put yours on the battery side.

If you had a single bank charger, having the ACR on the battery side would be helpful because you could then charge both at same time, but would lose the benefit having separate charging profiles. Just wanting to make sure I have my mind wrapped around this correctly.

 

[HangOutdoors]

@HangOutdoors with your multi bank charger, wouldn't you want the ACR on the load side of the switch instead of the battery side? That way when switch is off, batteries are completely independent of each other and have separate charging profiles? If ACR is on battery side, and a charge (either from engine or from battery charger) is present (regardless of battery switch position), won't the ACR close and combine the batteries?

after researching various threads on battery setup's, I came to the conclusion with my 2 bank charger directly wired to each battery, I should have the ACR on the load side. Just wanting to understand why you put yours on the battery side.

If you had a single bank charger, having the ACR on the battery side would be helpful because you could then charge both at same time, but would lose the benefit having separate charging profiles. Just wanting to make sure I have my mind wrapped around this correctly.

I switched mine, right away. It is on the load side. I guess I never updated the picture. That way with the switch off I take the ACR out of the mix. Technically you can do either and Blue Seas indicates the same, ultimately I decided to Isolate the batteries and charging with the switch off. Seemed better in my mind. Which is the same conclusion you came to.

 

[jcb1977]

I switched mine, right away. It is on the load side. I guess I never updated the picture. That way with the switch off I take the ACR out of the mix. Technically you can do either and Blue Seas indicates the same, ultimately I decided to Isolate the batteries and charging with the switch off. Seemed better in my mind. Which is the same conclusion you came to.

thanks for confirming- I'm going to put it on the Load side as well.

 

[meaningreen]

Haha after seeing your original post it inspired me to build a dual battery setup as well. Been working on it slowly, due to space had to break mine up into two as well. Adding Voltage displays and a 12V plug so I can fill the toys from the back of the boat without cutting into the boat. Still not eager to drill holes. I followed what Blue Sea suggested and went from ACR to battery, then battery to switch.

 

[HangOutdoors]

Haha after seeing your original post it inspired me to build a dual battery setup as well. Been working on it slowly, due to space had to break mine up into two as well. Adding Voltage displays and a 12V plug so I can fill the toys from the back of the boat without cutting into the boat. Still not eager to drill holes. I followed what Blue Sea suggested and went from ACR to battery, then battery to switch.

If you are going to use a charger that has more than one bank I would recommend switching it around. Otherwise looks fantastic. I have my digital readouts at the helm for voltate in a combo voltage/usb. Nice work

 

[jcb1977]

I wanted to post what I ended up doing using your install as a guide but did a few things differently.....before this I had installed a second battery with a single circuit layout (1/2/off/combine switch). I fried two connext displays for some reason, still not exactly sure why, but before I get the third screen installed I figured I should try changing something to try and avoid it. Figured I would try a dual circuit with on/off switch this time. I mounted the negative busbar on a piece of wood blocking using the bolts for the table holder (I do have a cover for the ground busbar but didn't have it on when I took the picture).

 

[HangOutdoors]

Looks good.

 

[jcb1977]

I bought the cables and connectors from www.batterycablesusa.com. I bought 7 feet of marine tinned copper battery in red and 7 feet in black. just had a little bit of red left but have a few feet of black left over. I used 3/8" connectors for ACR/Battery switch/positive battery posts, 1/4" connectors for the busbars and fuseblock, and 5/16" connectors for negative battery posts.

 

[meaningreen]

Spoke with Blue Sea, and if you wire it up per their drawings (Way I did it) and use a battery charger you just need to install a switch or relay on the GND on the ACR so it stops sensing voltage changes.(Thus turning it off). Which maybe could be useful in isolating the batteries on the water if need be. They also recommended you just charge the start, and the ACR will switch over to charge both, but I didn't like that idea for winter storage. Link to topic

 

[HangOutdoors]

I dont like the acr in the mix for charging on a bank charger, when my switch is off everything including the acr is isolated from the batteries. I guess you could put a switch on the ground but i dont like the idea. Also i have a multi bank charger and i prefer each battery has its own bank and charges in isolation when on the charger, much cleaner.

My star battery is wet. My house battery is AGM TPPL. I also have two LiFePo on the charger but only for trolling motor.

 

[meaningreen]

I dont like the acr in the mix for charging on a bank charger, when my switch is off everything including the acr is isolated from the batteries. I guess you could put a switch on the ground but i dont like the idea. Also i have a multi bank charger and i prefer each battery has its own bank and charges in isolation when on the charger, much cleaner.

I agree, but the switch on the GND turns the ACR off so it leaves the relay open when it senses a voltage. Either way works, just throwing out other solutions. My charger is dual bank and the batteries are isolated with the switch method. Just need to add another prelaunch item to the check list.

 

[212s]

My star battery is wet. My house battery is AGM TPPL. I also have two LiFePo on the charger but only for trolling motor.

Curious, do you have any issues with the DVSR staying on when in the water?
Does your AGM battery stay above 12.8v when fully charged?
Another user was having an issue with his DVSR staying on and connecting both the start and house banks when parked.

 

[HangOutdoors]

I don't have a DVSR I only have an ACR. The AGM is 12.8 when fully charged I believe.

 

[meaningreen]

Curious, do you have any issues with the DVSR staying on when in the water?
Does your AGM battery stay above 12.8v when fully charged?
Another user was having an issue with his DVSR staying on and connecting both the start and house banks when parked.

DSVR, are designed similar to ACR's when it senses a reduction in voltage due to the engine(S) being turned off it will isolate the batteries. Once the engine(s) starts back up and voltage rises due to start battery charged it engages the cross over and charges the house.

"The DVSR (Digital Voltage Sensing Relay) allows charging of two independent battery banks from a single charging source. When the voltage on the start battery rises to a charged level, the DVSR engages allowing the 2nd battery to charge. When charging stops and voltage falls, the DVSR will disengage, isolating the two batteries from each other. Dual sensing functionality enables the sensing of two battery banks, allowing two way charging. "

An ACR senses when the voltage of either of the batteries rises to a level indicating that a charge source is active (13.0V for 2 minutes). The ACR′s contacts then connect and the ACR applies the charge to both batteries. If the voltage on both of the batteries subsequently drops to 12.75V for 30 seconds, the ACR will disconnect, isolating the batteries.

Down side of the ACR is that it won't isolate the batteries until it reaches a certain voltage, and combines them for charging purposes. That's one of the reasons I added that extra switch so on the water if I truly wanted to isolate I could. Or how others have by placing the ACR on the load side of the switch, and turning it off. The other option to isolate is run the start isolation wire to a 12V wire that is hot only when you start the engine(s) IE the starter or solenoid for the starter.

 

[FSH 210 Sport]

I believe the ACR & DVSR function essentially the same, the Blue Sea system uses slightly lower pick up voltage (13.0 vs 13.4 of the BEP) and a longer delay (2 minutes vs. 5 seconds for the BEP), and a slightly lower drop out voltage (12.75 vs. 12.8 of the BEP). Both are dual sensing, meaning if either batteries’ voltage exceeds the pick up voltage the switch closes paralleling the batteries. Where this becomes an issue is when a LiFePO4 battery is used, the resting voltage of the LiFePO4 battery will keep the dvsr closed until it is almost fully discharged.

Having the ACR or DVSR active when charging the batteries with a two bank on board charger will work just fine, I think it’s better to have the ACR or DVSR inactive while the two bank on board charger is doing it’s thing. Another advantage of having the ACR or DVSR inactive while the on board charger is in use is to be able to run an equalizing charge (BU-404: What is Equalizing Charge? ) on flooded lead acid batteries, this is essential in maintaining peak performance. Most of the modern smart chargers will have a manually activated equalization charge and should be done once a month during the season.

When the batteries are fully charged and after a cruise on the water the voltage on the batteries will be at 14.1-14.3 volts, and the ACR or DVSR has put the two batteries in parallel. After stopping voltage on the two batteries in parallel will begin to decay, the rate of decay is determined by the load, and once the drop out threshold is reached the ACR or DVSR will break parallel between the two batteries keeping your start battery fully charged.

Here are a couple of differences that I see between the ACR and the DVSR.
1-The blue sea system SI that you guys have installed has the Start Isolation feature. Did either of you guys wire in this feature? The BEP DVSR has the same feature but appears to be automatically activated by nature of the low voltage drop out, and can be wired to work the same by either an ignition hot ( use the run only to energize the dvsr) or wire it to a rocker switch.

2- It looks like the Blue Sea system has a low and high voltage lock out that prevents the ACR from paralleling the batteries if the voltage is too low or too high on one of the batteries, I can see the advantages and disadvantages to that.

BEP Marine DVSR

https://www.bepmarine.com/-/media/inriver/710-140A_INSTR_BEP.pdf?modified=20211027183358

Blue Sea ACR

https://www.bluesea.com/resources/1366

Either way these two systems are pretty awesome in keeping the start battery isolated and fully charged, as well as providing fully automatic charging or manual charging while on the water. I have my BEP system set up as a manual charging with a rocker switch, but intend on connecting it to a run hot for next season, the reason for this is my house battery is a LiFePO4 batter and as mentioned above its resting voltage will keep the DVSR closed and the LiFePO4 battery will attempt to charge the AGM start battery.

All of you guys did a great job on adding in the second battery with the ACR system!

 

[FSH 210 Sport]

DSVR, are designed similar to ACR's when it senses a reduction in voltage due to the engine(S) being turned off it will isolate the batteries. Once the engine(s) starts back up and voltage rises due to start battery charged it engages the cross over and charges the house.

"The DVSR (Digital Voltage Sensing Relay) allows charging of two independent battery banks from a single charging source. When the voltage on the start battery rises to a charged level, the DVSR engages allowing the 2nd battery to charge. When charging stops and voltage falls, the DVSR will disengage, isolating the two batteries from each other. Dual sensing functionality enables the sensing of two battery banks, allowing two way charging. "

An ACR senses when the voltage of either of the batteries rises to a level indicating that a charge source is active (13.0V for 2 minutes). The ACR′s contacts then connect and the ACR applies the charge to both batteries. If the voltage on both of the batteries subsequently drops to 12.75V for 30 seconds, the ACR will disconnect, isolating the batteries.

Down side of the ACR is that it won't isolate the batteries until it reaches a certain voltage, and combines them for charging purposes. That's one of the reasons I added that extra switch so on the water if I truly wanted to isolate I could. Or how others have by placing the ACR on the load side of the switch, and turning it off. The other option to isolate is run the start isolation wire to a 12V wire that is hot only when you start the engine(s) IE the starter or solenoid for the starter.

Excellent post! I was working on mine since early this morning and had taken breaks and after I posted I see we had essentially written the same thing.

The SI part of the Blue Sea system is meant to isolate the house battery when starting the engines to keep the other electronics from experiencing the

 

[Tex72]

I’m doing something much more basic…I’m just adding a dual battery switch. I have one small/stupid question.

For the auto bilge: Do I need to connect it directly to one of the battery switch posts, or can I attach it to the engine/accessories post?

My preference, of course, is to have the auto bilge operational no matter which battery I choose, so I’m hoping it’s ok to connect it to the equip/acc post.

 

[HangOutdoors]

To the battery or too wherever the battery goes to on the switch, on the same post.

 

[Tex72]

To the battery or too wherever the battery goes to on the switch, on the same post.

That’s what I thought. I’ll hook it up to the battery 1 switch post…thanks.

 

[jcb1977]

I’m doing something much more basic…I’m just adding a dual battery switch. I have one small/stupid question.

I also initially installed the single circuit 1/2/both/off battery switch but recently switched to the dual circuit on/off. Just be very careful not to switch thru the off position, especially if the motors are on, but even with it off to be safe. Switch thru the both position instead to avoid voltage spikes. I fried two connext screens on my boat with the single circuit switch. One time was switching from 1 to 2 thru off while it was charging with boat off and that was enough to fried the screen.