ACR DISCONNECT

[HueyCrew]

I'm curious about the mention of disconnecting the ACR... and am I going to need to do something regarding it beyond the instructions it came with? My setup is 1 start, 2 true deeps for house wired in parallel, BlueSeas Combiner with ACR and Pro Mariner Elite 360 3 bank connected to the shore power beaker box. Even though the 2 house deeps are in parallel, the tech rep at ProMariner said give each one a set of leads from the charger. Also have a 3000W gen I plan on running to the A/C shore power inlet (and my CPAP from it's wall plug outlet) for overnight on the hook and in the AM if I'm staying put the day swap SH/PWR inlets to . If that wasn't enough, I have two 4"X12" solar panels, one for the start batt and the other.....planning on connecting in typical parallel config. mainly for keeping topped off during extended absence and planning on making that connection switched on my MBSS panel and connecting to terminal tabs along with bilge pumps attached to the main posts so I can leave MBSS off. I'm starting to confuse myself so I'll await some advice/ opinion. Still have to get at the existing wiring which had a 2 batt 2 bank setup, judging from the batt box "shadows" and an original 30 amp charger and off/1/2/both MBSS, but when we ran the engine and ops checked the systems there were no batteries and someone had zip tied all the negatives together and same with positive leads and used a 12V charger for power so I've got quite a task ahead for warmer weather. That I can handle but am confused about the ACR

Thanks

[HueyCrew]

This is actually what I have instead of an ACR I remember buying it packaged with the BlueSea batt combiner switch after doing some reading and it appearing to be a fairly simple operation and install....

Digital Voltage Sensing Relay (DVSR) 12/24V Part # 710-140A

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Digital Voltage Sensing Relay (DVSR) 12/24V 710-140A

The Digital Voltage Sensing Relay (DVSR) allows the charging of a second battery bank from any single charging source. When the voltage on the charged bank rises sufficiently, the DVSR engages allowing the 2nd battery bank to charge. When charging stops and voltage falls, the DVSR automatically isolates the battery banks, ensuring that engine start batteries are kept fully charged. Digital circuitry provides superior reliability and extremely low power consumption. Digital enhancements have introduced remote sensing circuitry that allows an optional connection from the ignition switch to provide the same functionality as single sense VSR and zero power consumption when engine is off. Another benefit is a zero stand by current draw when remote sensing circuit is utilized with a storage mode switch fitted (switch in open position).

• Safely charge two or more independent battery banks from one charge source such as an alternator or battery charger
• Charges engine starting batteries before combining auxiliary bank for charging
• Protects start batteries from becoming flattened by domestic loads
• Isolates electronics from harmful electrical surges from starter motors
• Simple to install 3 wire connection leaves alternator wiring intact
• No volt drop vs diode isolators
• Ignition protected
• Surface or panel mountable
• Replaces previous models 710-125A and 710-125A-DS
• Multi voltage, auto selects between 12 and 24V DC operation
• Digital circuits provide very low power consumption and enhanced performance
• Remote status LED output option
• Continuous rating: 140
• Engages: 13.2 VDC, Disengages: 12.7 VDC

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[Centerline2]

that is an ACR of a different brand... I believe the term "ACR" and "Automatic Charge Relay" is copyrighted by blue sea, so all others have to use a different description for their product that works in the identical manner...

[HueyCrew]

Gotcha....but there's no provision for any other wiring other than the larger gauge red leads that go to the combiner switch and the black wire that's tagged connect to a common battery negative.

[Centerline2]

Gotcha....but there's no provision for any other wiring other than the larger gauge red leads that go to the combiner switch and the black wire that's tagged connect to a common battery negative.

yep, thats all there is.... simple. connect one red lead to the positive of each bank, and the small ground/sensor wire connects to only one, but EITHER battery negative... done!!!

the simplicity and dependability of the unit is the reason they are the preferred way of charging multiple banks.

[Sunbird]

Both positive wires should be fused where they connect at the batteries. This is in the Blue Seas instructions.

[HueyCrew]

yep, thats all there is.... simple. connect one red lead to the positive of each bank, and the small ground/sensor wire connects to only one, but EITHER battery negative... done!!!

the simplicity and dependability of the unit is the reason they are the preferred way of charging multiple banks.

Yep Centerline, I looked at the bank, switching and charging options quite a while before i started ordering. Simplicity is my friend but once I started thinking about durability and redundancy ( after some hard lessons learned in my c/c). These batteries are in an awkward spot so I tried to plan the system so hopefully I won't be having to wrestle those things out for a long while. For what I'll be doing, I'm probably way into overkill overhauling and upgrading the electrical system but I'd rather have it and not need it than need it and not have it down the road. I'll have to dig up the diagrams but I was pretty sure they showed the small ground as I have it. on a bus with both banks. I'll double check. Sunbird, thanks, I'd forgotten as I built up the board last spring and it'll be a while before I'm ready to install. Just added then to my list needing ordering. Trying to get parts on hand ahead of time. Thanks guys!

[HueyCrew]

Any suggestions on amperage for the main fuses? It's pretty much the standard 2655. Mercruiser V8, trim tabs (newer Bennett auto up on shutdown) tilt Fridge, newer stereo and amp/sub combo (600W) GPS, 2 bilge, 1 water pumps, no inverters. Portable gen for aux charging via shore pwr plug if needed I have changed all the lighting to LED and am going from 10 to 8 ga main wires to new fuse blocks. Planning on separating the loads between the (factory?) reset breaker in the harness on the engine and the 30 amp that's on the board in #1 above. Just eBay'd fuses and they range from 100-300 amp. I may at some point add a 12V LED TV. I'd pretty much figured the ACR would handle mainly charging underway via alt and the solars to keep topped while away (auto bilge pumps) and 3 bank charger would take care of overnights in a slip and via the gen for nights anchored out. Not planning on a lot of overnighting (weekend once in a while) until I retire and by then I be ready longer adventures down the ICW between NC and Fl

[Centerline2]

Dave, as with ANY circuit, the fuses should be sized to protect the wiring, not the devices connected to the wiring..... after the main circuit is installed, later if other components are connected in down stream, the smaller wires to the components need to have their own fuses to protect themselves and the component..

with the ACR you have seems to have a continuous rating of 140amp, which is good.... can the wire size handle 140amps in the length of the run? if it can, I would use a 135-145 amp fuse... because any more than this is unnecessary, and much less and you may be losing potential thru the relay.

and yes, the small ground wire for the acr can be connected to a common buss, or a battery negative... or even to both batt negatives. bottom line is, it only needs to see a good a solid and stabile batt ground, so its not recommended to be grounded to the engine block or any other peripheral component that may build a resistance in the circuit over time as it transfers the ground to where is needs to go... the closer to the source that the connection is made, the less chance of failure somewhere in the circuit later...

[HueyCrew]

Dave, as with ANY circuit, the fuses should be sized to protect the wiring, not the devices connected to the wiring..... after the main circuit is installed, later if other components are connected in down stream, the smaller wires to the components need to have their own fuses to protect themselves and the component..

with the ACR you have seems to have a continuous rating of 140amp, which is good.... can the wire size handle 140amps in the length of the run? if it can, I would use a 135-145 amp fuse... because any more than this is unnecessary, and much less and you may be losing potential thru the relay.

and yes, the small ground wire for the acr can be connected to a common buss, or a battery negative... or even to both batt negatives. bottom line is, it only needs to see a good a solid and stabile batt ground, so its not recommended to be grounded to the engine block or any other peripheral component that may build a resistance in the circuit over time as it transfers the ground to where is needs to go... the closer to the source that the connection is made, the less chance of failure somewhere in the circuit later...

Thanks. I think I'm good. The MBSS/ ACR kit came with 3AWG ( 48" + and - ) and I have pre-crimped 2AWG for the paralleling connections between the two deeps in the house bank ( 16"). The original fuse blocks were in such poor shape, I installed BlueSeas covered blocks and have more spare connections than I'll ever need. The comm, trim tab "auto up" circuit and bilge pumps will run straight to the battery terminal bolt-on busses and be fused independently.

[TenMile]

So couple of comments for you.

First, if your house batteries are wired in parallel, there really is no benefit to connecting 2 of the 3 banks of your charger to it. When they are paralleled they act as a single 12v battery (with twice the capacity) so there's really no benefit to connecting the charger to both batteries. Your better off setting the charger for 2 banks, and coiling the 3rd set of wires away. Your wiring will be cleaner that way. And really, you could even consider connecting the charger to a single bank as your ACR will combine both the House and Start systems when the battery charger is operating anyhow. ACR's also have a nice safety feature that prevents it combining a dead battery with a good battery - so for example, if your start battery drops a cell, the ACR won't combine it into the charging circuit which prevents it from dropping the system voltage.

The ACR and the ProMariner do conflict with one another somewhat. Some of the advanced features of the ProMariner (for example being able to trickle charge the start battery while providing full charge output to the house battery) will be negated by the ACR because it will combine both banks once it sees the charge source. The ACR you own is actually made for a single bank charger -- they recommend connecting the charger to the start battery -- it charges first, then combines the house bank.

For your solar panels, do you know how many watts they are? Your ACR is very useful with solar panels but you mentioned yours are 4" x 12" which are probably 5 watts each. If that's the case, these types of panels are best for trickle charging applications as they provide about 1/3 Amp. Best to use when the DC power on the boat is all shut off as they don't provide much in the way of power.

[HueyCrew]

So couple of comments for you.

First, if your house batteries are wired in parallel, there really is no benefit to connecting 2 of the 3 banks of your charger to it. When they are paralleled they act as a single 12v battery (with twice the capacity) so there's really no benefit to connecting the charger to both batteries. Your better off setting the charger for 2 banks, and coiling the 3rd set of wires away. Your wiring will be cleaner that way. And really, you could even consider connecting the charger to a single bank as your ACR will combine both the House and Start systems when the battery charger is operating anyhow. ACR's also have a nice safety feature that prevents it combining a dead battery with a good battery - so for example, if your start battery drops a cell, the ACR won't combine it into the charging circuit which prevents it from dropping the system voltage.

The ACR and the ProMariner do conflict with one another somewhat. Some of the advanced features of the ProMariner (for example being able to trickle charge the start battery while providing full charge output to the house battery) will be negated by the ACR because it will combine both banks once it sees the charge source. The ACR you own is actually made for a single bank charger -- they recommend connecting the charger to the start battery -- it charges first, then combines the house bank.

For your solar panels, do you know how many watts they are? Your ACR is very useful with solar panels but you mentioned yours are 4" x 12" which are probably 5 watts each. If that's the case, these types of panels are best for trickle charging applications as they provide about 1/3 Amp. Best to use when the DC power on the boat is all shut off as they don't provide much in the way of power.

I thought the same about the banks and called their tech support and got that straight from them. And they said the leads should be the first things to go on the posts. Now...at that time I hadn't decided on the combiner/ ACR. So in that config, and the MBSS off, powering the charger via the gen of shore power, the ACR will still function with the charger leads direct to the batteries? I thought it was for underway and charging via the alternator. I'm confused now... Maybe I should just go back with a normal MBSS.... The solar panels are only for keeping the batteries topped off while I'm away ( yes, MBSS off) and leave her in the water to keep the memory in the stereo and top off in case of bad weather and the bilge pumps kicking on, both of which will be fused and direct to batt (s). I'm installing on/off switches for both solar panels on the MBSS panel.

[TenMile]

An ACR is a far superior option to an MBSS as far as I am concerned. I would never have a boat without an ACR and have installed them on my last 3. Its function is simple, when you have a dual bank battery system (Start and House), the batteries are typically charged from 2 sources -- the engine alternator(s) when the boat is running, or via a charger when the boat has AC power (either plugged in at shore, or plugged into a generator). When the ACR senses a charge source present on one of the systems it combines the two battery together and creates one large 12V system. It keeps them combined as long as the charge source is connected. It disconnects the two banks when it senses either the charge source shutting off or when the voltage from one of the systems drops below 12.7v (for example if the battery is used to start the engine).

The ACR will prolong the life of your batteries as it ensures that all banks are fully charged. They are also idiot-proof (which is why I installed mine) -- no more forgetting that you put your MBSS on "Both" and running all your systems down overnight.

Don't be confused by your generator. All it's doing is acting as a source of AC power and replaces the metered power you get when you plug in. Nothing more.

What I would suggest adding to your system is a battery monitor that can provide State of Charge (SOC). Trimetric or LinkLite make some good ones here and they generally run about $2-300. They come with a "shunt" that measures the Amps going in and out of your batteries. You tell it the Amp Hour capacity of your batteries and based upon what it measures going in and out the device gives you a very accurate reading of the overall charge of your system. I have a friend who fishes with me who has a CPAP machine -- we plug it into the boat power and run it off the Inverter/Battery system and I don't find that it draws the house bank down below 80% overnight. You might find that you don't need to run the generator. The battery monitors will also extend the life of your batteries and can pay for themselves over time -- no guessing whether or not your batteries are full. Using a dash volt meter is not an accurate way to measure whether a battery is full as it can't tell you when the battery is at 100% charged.

[Happy_Friday]

" And really, you could even consider connecting the charger to a single bank as your ACR will combine both the House and Start systems when the battery charger is operating anyhow."

+1 TenMile. This is the way I set mine up. Very intuitive once it is connected and much cleaner due to the less wiring.

[Centerline2]

Dave, its a simple thing, and you may be overthinking it... connect the acr into the system. the mbss should be one that is designed for use with an acr, which will have on-off-combine and NOT 1-2-combine... EXCEPT after installing the switch you will have to separate the the single circuit that comes from the mbss to the loads in to 2 individual circuits... which means you should have the house loads on one circuit, and the engine loads on the other circuit..
the mbss that is designed for use with an acr is just an on off switch for 2 parallel circuits running thru it.... and a position that will combine the two.... an OEM mbss is a "one or the other circuit" switch with a combine position. it would take multiple OEM switches and a good memory to do the same as what the new style switch does..

and connect all the charging sources to one bank, as well as the solar charge wire... its installed and DONE.
when there is NO input from the alternator or shore power charger, the solar charge will trickle in, and when either the alternator or shore power charger is active, the dominant source will tske over and charge...

the only thing is, as TenMile said, the dual or triple charge leads can potentially confuse the charger with the way that the acr works when the charger leads are connected independently to the two separate banks.... so connect ALL the shore power charger leads to the same battery post, and the charger will know what to do with itself after that, and so will the acr.... its a very simple system that works so well that its easy to think there should be more to it than there actually is..

you dont NEED to use the acr type of mbss switch, but to get full capability out of the system after installing the acr, the new switchiis necessary... or multiple old style switches.