Which battery switch do I need? Confused about the different kinds

[slag]

I'm looking at blue sea battery switches. I currently have a single battery and don't want to be stranded at the lake due to a bad battery or running it down. I want to have both batteries charge while underway, and have one battery stay full while one is used for the accessory port and radio and everything else. I thought I wanted a blue sea 9002e switch with AFD, but that will require constant manipulation of the switch and I read this blurb on a blog:

"The problem is that this requires a lot of thought by the operator, who is trying to relax in the first place. Inevitably, the operator (or the operator’s Brother in Law) may leave the switch in the BOTH position, resulting in a very dead battery. Statistically, dead batteries are one of the most common reasons for calling a towing service. “I can’t crank my engine!” is right up there with “I’m out of gas!” for ruining a day on the water."

If I loan my boat out to a relative or my wife takes friends out, I don't want to have her worry about remembering which switch does what. So then I read up that this one would be better for me, the 5511e, but don't understand why it is better.

"A simpler alternative to isolate your Start and House circuits is available in the Dual Circuit Plus Battery Switch (5511e). In the ON position, it keeps your batteries isolated, so both can’t be fully discharged by accident. In the COMBINE position, it parallels your batteries in the event of a low Starting battery. Used with the 7610 Automatic Charging Relay (ACR), it automatically combines or isolates your batteries when in the ON position."

How can it "automatically" combine or isolate the batteries? Does that mean I would need to run separate wiring from the blower/acc port, stereo, etc back to just one battery instead of using my existing wiring? Sounds like a headache to me.

Here's what I want. I want to charge both batteries, but keep one isolated from the other without having to do anything more than simple wiring up of different terminals at the battery end and not constantly manually switching back and forth between batteries. If this is not possible, it sounds like the first option would be the best and easiest to implement. Also, it needs to be cheap. I already have two batteries, just need input on what switch to buy to do this with minimal effort from others who might use the boat.

 

[dingbat]

No cheap and easy fix to the problem. First, you have to isolate the starting circuit from the rest of the wiring. Meaning, starting circuit on one battery, everything else on the other. Once done, you install and connect the ACR relay between the switch and the batteries. Plan on good 1/2 day of labor and $200- $250 in parts

 

[sam am I]

Got one in the mail............sooooooo excited!! It's the little things eh? I'll post some data in-between upcoming Kokanee and Chinook of course.

 

[slag]

I'm thinking the 9002e is the way to go for me in order to keep costs low and installation at a minimum. I'll just mount the switch on the bottom lower of the rear seat in front of the sundeck. It will allow me to keep a "hot spare" ready if I need it, and just use the other batteries as needed. The 9002e allows me to switch from battery to battery on the fly also so if one gets low and won't crank the engine, I'll start it with the other battery, then switch to the bad one to charge as the engine is running.

 

[NYBo]

No cheap and easy fix to the problem. First, you have to isolate the starting circuit from the rest of the wiring. Meaning, starting circuit on one battery, everything else on the other. Once done, you install and connect the ACR relay between the switch and the batteries. Plan on good 1/2 day of labor and $200- $250 in parts

Huh? The two systems should already be separate, and in your scenario, only an ACR or similar device is needed (no switch); ACRs start at around $100.

 

[ihearth2o]

Huh? The two systems should already be separate, and in your scenario, only an ACR or similar device is needed (no switch); ACRs start at around $100.

Not necessarily. My boat has two batteries but the house and starter sides are not isolated. The "second" battery is set up to be the "back-up"…I was told this is the "old-school" way of wiring for two batteries. For my application, I didn't bother trying to trace which wire went to what to separate the house and starter sides. I just connected the positive terminals to the ACR. Then instead of turning the switch to "COMBINE" (although on my perko switch, it is called "ALL"), I just leave the switch on one of the batteries. That way, if I drain one battery, I can just switch over to the other (fresh) battery. Then when my engine is running, the ACR will allow both batteries to charge without having to manually toggle the switch to "ALL". This application may not work for everyone but for me it accomplishes the same thing as if I had rewired…it prevents me from draining both my batteries and I don't have to worry about manually toggling the switch.

FYI…Blue Sea ACR is like 80 bucks on amazon

 

[NYBo]

Not necessarily. My boat has two batteries but the house and starter sides are not isolated.

This is not the setup dingbat described. No switch is needed if the goal is to keep the house and motor loads completely separate except for charging.

 

[ihearth2o]

I was referring to your comment on how the two systems should already be separate. I took that to mean that boats are already wired to have the starter and house sides isolated. Mine was not so I was just trying to add some color to your comment. I will shut up now…..

 

[NYBo]

I was referring to your comment on how the two systems should already be separate. I took that to mean that boats are already wired to have the starter and house sides isolated. Mine was not so I was just trying to add some color to your comment. I will shut up now…..

Ah, I see. My mistake. The usual setup is for the fuse block feed (house load, essentially) to use 8 or 10 gauge wires directly to the battery, at least in the small boats with which I am familiar.

 

[slag]

Huh? The two systems should already be separate, and in your scenario, only an ACR or similar device is needed (no switch); ACRs start at around $100.

The two systems are not separate unless I just am not understanding correctly. I have one battery lead going to positive and one going to negative. All my extraneous power needs are wired in to the main power trunk which is at some point tied into the wiring harness. I don't really want to muck around with this configuration if at all possible. I just want to be able to know I have a good battery to use to start the boat when needed that, at most, will require a quick flip of a switch to access.

 

[sam am I]

The two systems are not separate unless I just am not understanding correctly. I have one battery lead going to positive and one going to negative. All my extraneous power needs are wired in to the main power trunk which is at some point tied into the wiring harness. I don't really want to muck around with this configuration if at all possible. I just want to be able to know I have a good battery to use to start the boat when needed that, at most, will require a quick flip of a switch to access.

Yours probably aren't

These guys ^^^^ are talking about the powered loads and grouping(or if they already are) the loads off into two isolated systems if you will, and with that, what loads each of the two installed batteries in this isolated system can see(power) in the normal running/sitting mode.........

For example, and still using the switch you have proposed primarily for "on the fly" start re-config's

Your "start battery" will be dedicated and wired to power just the starter and the ig. and perhaps bilge systems.....the bare minimum essentials to start and run the motor and keep the boat a float.

Your "house battery" on the other hand is the battery that powers like lights, radio, down riggers, TV's, hot tubs and the like.

So, given the above "separated systems" config'd and in "normal" get in and go default switch lineup, and w the motor off and not charging obviously, you can use and kill the house battery and still have the start battery plenty good to go.

To fire up, no switching needed, just turn the key, motor starts and the VSR/ACR/Alt charge management system senses things and poof, it automagically configures/charges your dead/low battery(ies) while you relax in the comfort of your own skin.

Basically like having some guy named Ted dedicated to just running your manual switch for you as your day in the sun requires. Ya run down the lake, shut off......rinse, lather, repeat! As stated, no switching needed.

You're fine with what you propose with adding a switch, spare battery and having all things powered from the "common" stock wiring of the boat as is, ya just have to remember to be Ted as well and manually switch it around for usages, charging and isolation as required/needed, did it for years, it works fine and actually? Is probably the most reliable method there is.......short of the human/Ted got drunk and forgot factor.

 

[ihearth2o]

If your switch is (or plan to be) mounted in a convenient spot, a simple 3 terminal switch should suffice. In my situation, the battery switch is in my engine compartment which means pulling open the engine hatch/sunpad. With passengers comfortably seated, especially little kids or adults holding little kids, it becomes very old, very fast to have them shuffle themselves and gear around every time I needed to toggle the switch. I could have relocated my battery switch but, as previously mentioned, there is still a human factor to consider.

If you are good about manually toggling the switch to one of the batteries (so that you don't drain both batteries) when you are anchored and manually toggling it back to "ALL" (to charge both batteries while underway) when you are pulling anchor, then again the manual option would suffice. If you are prone to distraction, i.e. kids, ladies, beer, etc., the ACR will eliminate most of the human factor. Of course, you have to add the ACR to your checklist for the day to see if it's working.

 

[Silvertip]

As usual, folks seem to way overthink how a dual battery switch should be/can be used. It does not need to be constantly mucked with, or at best, only when you anchor for long periods of time with a high power stereo and other gadgets in use. This has been discussed so many times in this forum I won't get into it again. If one is "switch challenged" then an ACR is all that is needed. Lastly, if your wife, brother in law, father, or anyone else is allowed to use your boat, then the best protection against problems is "education".

 

[slag]

As usual, folks seem to way overthink how a dual battery switch should be/can be used. It does not need to be constantly mucked with, or at best, only when you anchor for long periods of time with a high power stereo and other gadgets in use. This has been discussed so many times in this forum I won't get into it again. If one is "switch challenged" then an ACR is all that is needed. Lastly, if your wife, brother in law, father, or anyone else is allowed to use your boat, then the best protection against problems is "education".

Ain't that the truth. Check the oil, check the gas, turn the blower on, make sure the boat isn't tied down to the trailer before launching it, make sure the fenders are out, make sure the plug is in, make sure the keys are in the boat, make sure the kids all have the life jackets on, make sure nothing will blow out while on the water. Is the outdrive up? Lower it before starting the engine.


Whoever said boating was fun or relaxing