2007 Sv211 dual battery configuration

[wakewatcher]

I'm the proud new owner of a used, but perfect, 2007 sv211. I've got a question about the dual batter switch. It seems my after market tower lights were hooked up to battery number 2. I've been running my boat with battery number 1 assuming it charges both batteries all the time. (I'm mean what's the point if it doesn't? I was assuming what running off one battery did for you was save the other in case you foolishly rundown the starter battery so then you could switch over to the reserve. Well apparently my tower lights ran down battery number 2 which wasn't being charged because the boat was on battery number 1. Is that possible?

[HS]

I think it is the case (until the next poster proves me wrong).

My understanding of the "Perko" switch is that when the dial is pointing at "1", for instance, battery 1 is in service and battery 2 is "isolated", i.e., not in service and not being charged, either.

I alternate batteries by the odd / even date: if its the 1st, I am on battery 1, if its the 22nd of the month, I am on battery 2. Another way I try to alternate the battery I use is by trying to use the one I did not use the last time out.

I have heard some guys will cruise and run the engines on "both", but once the boat is turned off, say to hang at the beach, they turn to 1 so that 2 stays fresh for when it's time to go...interested in hearing how the others here use their 2 batteries. I don't have a huge sound system or tower lights, though.

[ski4evr]

Yes, all accessories should be hooked to the main fuse panel. That way, whichever battery is selected 1,2, or both will run the entire boat and that battery is being charged by the engine. I typically run batt 1 saturday, and batt 2 on sunday to equally exercise both batteries.

[TxJole]

Main question is does your switch have a 1+2 spot or just a 1 and 2 and off??

[wakewatcher]

I'll have to take a look at it. (I don't have access right now) but I'm guessing there are two things at play here. First whoever installed the tower lights hooked them to one of the batteries rather than the output of the switch. And apparently when charging it doesn't charge both at all times as I believe motor homes do.

[fech98]

I was told when I bought my boat to keep it on both 1 and 2 all day long and never change it? I guess that is not correct, but I have 3 amps and tower speakers and I have never had a dead battery or anything of that matter!

[core-rider]

There should be a battery wired to each numbered post (battery 1 to post 1, battery 2 to post 2). The common post should go to the main power panel, starter, etc.

If the switch is on "Off" no power goes to the boat. Switch set to either "1" or "2" only the selected battery will power the boat and the other will be isolated (including isolated from the alternator think of it like you took the cables off that battery). If the switch is set to "Auto" both batteries will power the boat and be charged by the alternator.

[core-rider]

Sorry, I meant "All" not "Auto".

[Mikeski]

There are better ways to utilize your batteries than the way the factory sets it up. Send me an email if you want my optimized diagram. It will require you to do some rewiring but it will be fully automated and eliminate the possibility of draining your starting battery with accessories left on.
mikeskiw@gmail.com

[Super_sport]

I have a Perko switch wired to two batteries.. Bat 1 and Bat 2.. The switch also has an OFF position and an "ALL" (or 1+2) position. I do not have an updated 100amp alternator, I just have the stock 55 AMP alternator that came with the GT-40 Super Sport... I alternate the battery usage. When I cruise, I use one battery and when I sit I use the other.... I have a cranking/starter bat and a Deep Cycle Marine (non Gel, non AGM) on the other.. would it be recommended not to run the ALL switch while cruising to charge both batteries at same time with the 55AMP Alt? or is it better to just run 1 at a time? Cranking bat and Deep Cycle are both non Gel, Non AGM I think?

[HS]

Up until now, over the winter months I remove the batteries and periodically top them off with a trickle charger. They are installed when the boat gets de-winterized in the spring time. I will use battery 1 on day one, then I use battery 2 on day two. Doing this I am beginning to realize that I am depending on the "ride back to the dock" to charge up battery 1 before shutting down the boat and putting it away for the night, and next day, I go out again and use battery 2.

Assuming I am not thinking of having a charging relay installed, I am thinking I would be better by starting on 1, then switching to all while running and cruising, and then switch to 2 for hanging at the beach. Then when we leave, turn to 1 to start, and then once started switch to all for the cruise home.

[Mikeski]

Boat Battery Diagram.pdf
Here are 2 diagrams, electrically they are the same except one has a perko and the other does not. They both utilize a Yandina C100 or C150 charging relay. This could be substituted with the Blue Sea unit that Earmark sells too. Sorry they are not that pretty.

There are a few different ways to do this, I have had over 5 years of complete success with my configuration, never a dead battery so I am just sharing my opinion and success. I am an electrical engineer and I work with DC currents being in the solar power industry so I probably have a bit more experience making this kind of stuff work than boat builders. Still, it is possible it could be done better?

best of luck, Mike