Battery switch DIY?

[Meyeronfire]

Thanks for all the reply's everyone. Has anybody used the add a battery from blue sea?http://www.bluesea.com/products/cate...ttery_Switches

[Wylietunes]

I use the same switch and ACR quite often, i just stock them as individual components.

[jzelt]

I have the same setup as MJHKnox shows. Works very well. We alternate the switch (a couple times a summer) in order to change the primary battery due to them both being the same, that way, one stays draw and the other stays charged.

[CJD]

I'm no expert, and really just thinking out loud. I would think that using the solenoid to combine the batteries for a start would be the same as flipping the manual switch to "both".

[Wylietunes]

I'm no expert, and really just thinking out loud. I would think that using the solenoid to combine the batteries for a start would be the same as flipping the manual switch to "both".

Providing that the voltage on the control side of the coil doesnt drop too low during cranking and allow the solenoid to open.

[Meyeronfire]

Thanks for all the feedback guys, I think I have made a decision on which battery switch I want to use. I think the four position blue sea is going to be my best bet. http://www.iboats.com/High-Performan...view_id.197226 So now I need to wire it up correctly and some help with that please! I don't want to screw up the alternator of have and electrical issue due to incorrect wiring.

[SquamInboards]

The switch you linked to is the one I use now after having several other setups. An isolator is great and you never have to touch it, but I like the absolute certainty of a switch so I know which battery I am using. I mounted mine right next to my stereo so I can see it when I am right there, and I can easily reach it (or ask the passenger to reach it) when I need to.

Wiring is somewhat dependent on your boat's wiring currently, but generally very simple. How many wires do you have going to each post on your current battery? In a perfect scenario, you have one going to each. In that case you ground each battery to the engine (or connect them to each other and have the existing main ground wire go to either battery), then connect each positive terminal to each side of the switch, and the main existing positive wire to the 'common' post on the switch.

A quick google image search led me to this page: http://bluewatermarinesvc.com/html/bat_switch.html with a decent diagram of how it should look. Your accessories would also come off the 'common' post of the switch in one manner or another. If you have multiple positive wires, you may not want to put them all on the common terminal on the switch but you might want a distribution block of some kind; the same goes for ground.

Regarding alternator damage, the switch you're looking at has what it calls 'make-before-break' protection, meaning it connects the next battery before disconnecting the one you're coming from, so the alternator is always finding its proper charging field or whatever it is looking for exactly. Just DO NOT switch it to OFF with the engine running. Switching from 1 to Both to 2 and back, it's designed to maintain a connection the whole time, so you should be safe.

[Meyeronfire]

The switch you linked to is the one I use now after having several other setups. An isolator is great and you never have to touch it, but I like the absolute certainty of a switch so I know which battery I am using. I mounted mine right next to my stereo so I can see it when I am right there, and I can easily reach it (or ask the passenger to reach it) when I need to.

Wiring is somewhat dependent on your boat's wiring currently, but generally very simple. How many wires do you have going to each post on your current battery? In a perfect scenario, you have one going to each. In that case you ground each battery to the engine (or connect them to each other and have the existing main ground wire go to either battery), then connect each positive terminal to each side of the switch, and the main existing positive wire to the 'common' post on the switch.

A quick google image search led me to this page: http://bluewatermarinesvc.com/html/bat_switch.html with a decent diagram of how it should look. Your accessories would also come off the 'common' post of the switch in one manner or another. If you have multiple positive wires, you may not want to put them all on the common terminal on the switch but you might want a distribution block of some kind; the same goes for ground.

Regarding alternator damage, the switch you're looking at has what it calls 'make-before-break' protection, meaning it connects the next battery before disconnecting the one you're coming from, so the alternator is always finding its proper charging field or whatever it is looking for exactly. Just DO NOT switch it to OFF with the engine running. Switching from 1 to Both to 2 and back, it's designed to maintain a connection the whole time, so you should be safe.

Thank you A lot man! Nicely put and simple enough. I actually changed my mind at the last minute and went ahead and purchased the add a battery with the ACR from blue sea. Trying to make it wife proof, so all she has to do is turn to on when she wants to run the boat and off when the boat is off. I hope this works out well. I believe there are four posts on the back of this particular switch though.

As far as wiring at this time is your main positive battery post with positive wire to boat engine, negative post with negative wire grounding to boat, then small negative wire from the small neg post to battery.

[SquamInboards]

Sounds good, I've thought about that exact combination, but again I just like to have the simple 4-position switch, personal preference and it works well with the way the boat is set up.

Funny you say "wife-proof" due to the location of the switch, my wife has used it more times than I have probably. Anyway you're definitely saving yourself future headaches with two batteries. This summer will be my 9th with this boat, and the only time I've been left with a dead battery was right before I put in the original switch setup.