How to properly use 2 batteries -2016 Sundeck

[Sea-Ya]

Switching from 1 to 2 to both is fine, just don’t switch to or past off.

Ok, Thank you

 

[Namakan]

I bought a 2020 SPX 230 this summer with dual battery. I was told both batteries would be charged when running on either 1,2 or both?

 

[scoflaw]

I bought a 2020 SPX 230 this summer with dual battery. I was told both batteries would be charged when running on either 1,2 or both?

Not sure of your wiring configuration, but that switch isolates the batteries, so a charge isn't going to charge both when set to 1 or 2.

 

[Lazy Daze]

I bought a 2020 SPX 230 this summer with dual battery. I was told both batteries would be charged when running on either 1,2 or both?

Depends. That would only be true if something like an ACR was also installed. Take a look at your battery wiring.

 

[Namakan]

Depends. That would only be true if something like an ACR was also installed. Take a look at your battery wiring.

I’m not much of an electrician so I really don’t know what to look for?

 

[Lazy Daze]

I’m not much of an electrician so I really don’t know what to look for?

If you follow your battery cables, look where they go. The positives will go right to the switch. If you have an ACR (Google for automatic charging relay), then that will be wired BETWEEN each battery's positive terminal.

 

[RockinRick]

1) The alternator will only charge the connected battery with a normal 1+2 switch. There is an inexpensive electrical widget called an Automatic Charging Relay (ACR) that will charge both batteries whenever the engine is running. It senses charge voltage and opens up a connection to both batteries, then disconnects when the system is discharging the batteries. This way you can run on 1 or 2 and use the other as a true backup. Blue Sea Add A Battery and Add A Battery Plus kits are popular and well regarded. I installed a plus kit so that I can plug it in at home the night before we go out, one of the best improvements I have made to the boat.

2) If you are running on #1, then you should anchor on #2. That way if your radio goes dead because you didn't have a full charge on #2, you still have your starting battery fully charged.

3) I am a relative newby, but I got stranded using the 1+2 switch in both. I am not sure how, but one of my batteries failed in a manner that kept the other from charging properly so that I didn't have enough juice to start the boat. Ended up buying two new batteries (because if they are interconnected you want to keep the same type and age) and the ACR. I always run on one battery now.

4) The bilge pump is wired directly to battery 1 as well as the bilge switch at the helm through 1 or 2, whichever is currently selected. The electronics will run off whatever battery is selected as well. The small bowriders don't have house batteries, although you can set one up using the blue sea kit. I didn't install the blue sea switch, but plan to create a house battery for the radio this winter because starting the boat interrupts the bluetooth connection.

So the input to the ARC is alternator and or other dc charging voltage?
Do you then leave 1,2,both switch in position 1 and use it as dedicated start battery? use Battery 2 as dedicated House battery? and if needed place 1,2, both switch in both position to assist battery 1 with starting?

 

[Wylie_Tunes]

So the input to the ARC is alternator and or other dc charging voltage?
Do you then leave 1,2,both switch in position 1 and use it as dedicated start battery? use Battery 2 as dedicated House battery? and if needed place 1,2, both switch in both position to assist battery 1 with starting?

Most typical Auto Combining Relays or Voltage Sensing Relays, are 2 posts. They simply combine or isolate the house bank from the main bank, depending on voltage. The main bank always sees alternator charge when engine is running.

I would not assume that 1 is main cranking and 2 is house. of course, if both batteries are the same, then neither is either.

Here is where it gets fuzzy, and why I do not like to pair the 1/2/BOTH with an ACR. In an ideal setup, ALL loads go through the switch, making neither battery truly dedicated to anything. Regardless of what the ACR does with the engine running, you still have to manually use the switch, depending on how you use the boat. Just because bank-2 gets a charge with engine running, does not mean bank-1 has no loads drawing off it, when at anchor.

If there are loads wired direct to a battery, circumventing the switch, then the boat has the wrong switch!

 

[ColoSR]

My boat has 2 loads that were factory wired directly to the battery, the bilge pump and stereo preset. I plan to leave those as-is because too much water sounds like a more expensive problem than battery replacement

There are two switch types that I looked at (a) a 4 position selector, which is the one that we are calling 1+2 or both, and (b) a dual circuit switch which is a house/starting battery switch.

With the 4 position selector, both the engine and electronics are connected to a single pole. The connected battery is charged by the alternator when the engine is running, per the switched to 1 and both position snips attached.

The dual position switch has two distinct circuits, the engine and house. Turning the switch to "ON" connects battery 1 to the engine and battery 2 to the house loads. Turning the switch to "COMBINE" connects both batteries to the engine & house load so you can start in an emergency (see Dual Circuit snips). Without an ACR, the dual position switch wont charge the #2/house battery.

Finally, the ACR sits in between the 2 batteries, and closes a connection between the 2 batteries whenever the engine/alternator are running. Power flows from the alternator, to battery #1/start, then through the ACR to battery #2 per the attached install diagram.

Many here have noted that there is no need for a house battery on a runabout, which is why I installed my ACR/battery charger to my factory 4 position switch. In my case, I am changing from 4 position to a dual circuit, start/house, configuration because we use the boat primarily for water sports and I have to reconnect the iphone to the stereo every 10 minutes or so when I stop and restart the boat. By having the engine/gauges connected to the start battery and stereo/GPS to house battery, I can isolate the stereo from the starting current.

 

[Wylie_Tunes]

"many here noted that there is no need for a house battery on a runabout"

I would argue that this needs to be based on boat use and not by size or type of boat. I know HUNDREDS of boaters with a house bank that gets used as such. Toons, day boats, runabouts, wake boats, etc.

 

[Lazy Daze]

"many here noted that there is no need for a house battery on a runabout"

I would argue that this needs to be based on boat use and not by size or type of boat. I know HUNDREDS of boaters with a house bank that gets used as such. Toons, day boats, runabouts, wake boats, etc.

No doubt. Stereo use - especially upgraded stereos with amps/subs - can draw a lot of power.

 

[ColoSR]

Fair point. Going back through the thread it appears that about 1/3 of people are running on a 4 position in "both", so one big battery; about half are running on 1 or 2, which is essentially 2 starting batteries; and the balance are running with ACR's, house batteries, etc. Everyone has their own personal situation, so no wrong or right here.

 

[Lazy Daze]

Everyone has their own personal situation, so no wrong or right here.

True. A lot of this is personal preference. Plus, this thread is an EXTREMELY small sampling of boaters with dual batteries. And, I do agree with the others that it's best not to run on "both" as it could mask problems or even create worse problems, as mentioned. A battery that was used extensively with the engine off will also charge up better when it's the only one being charged.

 

[OllieC]

I’m not sure if this is mentioned however you should consider charging times via the alternator or also having an onboard charger for dual batteries.

For me, most of my trips are 1/2 hour to an hour or even more, one way, giving ample charging time to the house battery I use while anchored.

If you are in your runabout, going to the middle of your small lake, anchoring and listening to tunes all day, then running back to your dock, you may not have a good or full charge for the next time you’re out even if you have two batts. My buddy wanted to put a dual bank of group 27s on his 25hp pontoon, when he does the exact same thing I mentioned. It would take him forever to recharge those things IMO with that 25hp Honda. He also has no power at his dock.

 

[Bob from Kamp Kozy]

Great points on charge time thanks

 

[RockinRick]

Most typical Auto Combining Relays or Voltage Sensing Relays, are 2 posts. They simply combine or isolate the house bank from the main bank, depending on voltage. The main bank always sees alternator charge when engine is running.

I would not assume that 1 is main cranking and 2 is house. of course, if both batteries are the same, then neither is either.

Here is where it gets fuzzy, and why I do not like to pair the 1/2/BOTH with an ACR. In an ideal setup, ALL loads go through the switch, making neither battery truly dedicated to anything. Regardless of what the ACR does with the engine running, you still have to manually use the switch, depending on how you use the boat. Just because bank-2 gets a charge with engine running, does not mean bank-1 has no loads drawing off it, when at anchor.

If there are loads wired direct to a battery, circumventing the switch, then the boat has the wrong switch!

Personally this switch was a good idea 30 years ago. My idea is to split the battery's and make them dedicated. #1 is solely for starting, #2 is house\everything else and was going to accomplish this with a smart isolation switch (still researching the best) like in this link https://www.wirthco.com/battery-doctor/isolator I haven't read up on this one completely. But looking for one that when boat running it will give priority to charge start battery before charging house and when starting, if start battery for some reason is low bypass isolation and allow house battery to assist with start. So far I have only found ones that allow for manual bypass, which would do I guess. IMO this dual switch equals a quick way to strand you, plus I don't want to jerk with a manual switch.

 

[RockinRick]

Does anyone know what the output amps is on the 230MR V8? I have the manual but dont see it listed.

 

[ColoSR]

The mercury parts catalog says its a 55 amp motorola

 

[Lazy Daze]

Does anyone know what the output amps is on the 230MR V8? I have the manual but dont see it listed.

I wouldn't assume that the original alternator is on there - nor that a replacement is exactly the same. You've got 35 years of who-knows-what's-been-done-to-the-boat going on. It could be the same - but assuming you're asking because of fuse sizing - probably best to find out for sure.

 

[Wylie_Tunes]

Personally this switch was a good idea 30 years ago. My idea is to split the battery's and make them dedicated. #1 is solely for starting, #2 is house\everything else and was going to accomplish this with a smart isolation switch (still researching the best) like in this link https://www.wirthco.com/battery-doctor/isolator I haven't read up on this one completely. But looking for one that when boat running it will give priority to charge start battery before charging house and when starting, if start battery for some reason is low bypass isolation and allow house battery to assist with start. So far I have only found ones that allow for manual bypass, which would do I guess. IMO this dual switch equals a quick way to strand you, plus I don't want to jerk with a manual switch.

The device in your link, is an ACR/VSR. As stated, with the simple 2 post ACR's, the wiring is such that the main cranking always gets alternator charge. The device has zero bearing on that, despite the claim in the link.

States its waterproof, but is it ignition protected?

Yes, dropping anchor and leaving a 1/2/BOTH switch on BOTH, could leave you with 2 dead banks. However, this chance is slim, and far out ways the cons of eliminating the dual bank switch all together.

Not a fan of having large loads wired direct to a battery, with no main disconnect. Your plan is to just that. here is a far better switch design to pair with an ACR, a Dual Circuit Plus switch. Gives you a main disconnect for when the boat is not in use, yet divides the banks in a dedicated main and house.