Dual Batteries - Sanity check

[hyphen79]

All, I am about to add a second battery to the boat later this week, and wanted to double check that I have my logic in order.

What I have in the boat now:
OEM battery wired to On / Off switch that came stock with the boat (click the link to view existing switch)
Rockford Fosgate P550.1 amp wired to the OEM battery

What I want to do:
Existing battery (original) = Battery 1
New Battery = Battery 2 (deep cycle)

Wire Battery 1 to the 1 post on the perko
Wire Battery 2 to the 2 post on the perko
Take the existing wire (BIG RED wire) and wire it to the common post
When, done I can then place the power for the amp onto Battery 2

I just threw together this diagram to get a visualization of what I need to do. Does this look right?

[talltigeguy]

If you put your amp on battery 2, and then put your perko switch on 1, then remember that your amp will kill battery 2 and the accessories will kill battery 1 and you are left with no power.

I actually do it that way, but I know how it is wired and don't screw up. If you want true full functionality, then all powered electronics should come off of the common power post on the Perko switch.

[bigdaddy_houseboater]

Im not sure... but Mike will be... I think you need an isolator for a 2-battery all situation.
Again, check with Mike (chpthrill)

[hyphen79]

If you put your amp on battery 2, and then put your perko switch on 1, then remember that your amp will kill battery 2 and the accessories will kill battery 1 and you are left with no power.

I actually do it that way, but I know how it is wired and don't screw up. If you want true full functionality, then all powered electronics should come off of the common power post on the Perko switch.

I do like your idea of running everything to the common post, but that just seems to be a pain if I want to add something. I would have to unscrew the perko to gain access to the post.

I know I am going to be sitting for a bit I could just turn the switch to battery 2. Then everything would be running off of that battery. Then when we are ready to take off and play for a bit I could switch back to battery 1, start the boat up, switch back to battery 2 and the ALT will charge that battery while we are running around. Right?

I know if I switch to 1+2 then it presents the batteries as being one, and the less charged battery will pull from the other battery to recharge.

[chpthril]

Since you will be running a manual iso/combiner, then everything except the bilge needs to be on the "C" post of the switch. To keep from over crowding the "C" post, get a remote battery post and mount it on the transom and connect it to the switch with a short length of 1/0. Then connect all the added accessories to the remote post.

[lohe]

Just a FYI you should not flip the switch with the engine running...

I went with this setup so I dont have to keep flipping a switch does it automatically, Just turn it to on at the start of the day and shut it off at the end, and in case of emergency starting you can flip it to both.


http://bluesea.com/category/2/productline/overview/329

[chpthril]

Just a FYI you should not flip the switch with the engine running...

I went with this setup so I dont have to keep flipping a switch does it automatically, Just turn it to on at the start of the day and shut it off at the end, and in case of emergency starting you can flip it to both.


http://bluesea.com/category/2/productline/overview/329

Actually, the Perko, Guest and Bluesea brand switches are make-before-break, so its safe to switch between batteries, just not to off with engine running.

The thing I do not like about the switch that comes with the "add-a-battery" kit is the switch is "1" or "Both". I dont like the idea of combining a dead battery with a good battery for an emergency start. I buy the 7610 by itself and go with a Bluesea 1/2/both/off switch instead.

Combining a fresh battery with a depleted battery for too long, and they will level out and both with be low.....maybe too low to start the engine. Having the option to switch to a dedicated battery to start is best IMO.

[lohe]

Actually, the Perko, Guest and Bluesea brand switches are make-before-break, so its safe to switch between batteries, just not to off with engine running.

Ahh I did not know this good info.

[talltigeguy]

I do like your idea of running everything to the common post, but that just seems to be a pain if I want to add something. I would have to unscrew the perko to gain access to the post.

I know I am going to be sitting for a bit I could just turn the switch to battery 2. Then everything would be running off of that battery. Then when we are ready to take off and play for a bit I could switch back to battery 1, start the boat up, switch back to battery 2 and the ALT will charge that battery while we are running around. Right?

I know if I switch to 1+2 then it presents the batteries as being one, and the less charged battery will pull from the other battery to recharge.

You are exactly right, and that is how I run mine. As long as you are in charge, the boat will be fine that way. Downside is that you can run the stereo with your battery switch to 1, while the boat is running, and battery 2 dies while the boat is running if you forget to switch to all or 2. I have done that. Not a big deal, because I also have an onboard charger to bring them back quickly and they are AGM's that should tolerate a greater number of full drawdowns.

When you sell the boat, you will likely confuse the next owner.

Actually, the Perko, Guest and Bluesea brand switches are make-before-break, so its safe to switch between batteries, just not to off with engine running.
.

Seemed like when I bought mine just a few weeks ago, there were some that did that and some that did not. Maybe the ones that did not have the fail-safe were old stock?

[hyphen79]

2nd battery is installed!

I forgot to take a picture before I started, but here it is after I took the cranking battery out(original).




Here is the final product. I ended up adding a remote / accessory post off of the common on the perko. All added equipment will run off this, and I will have to remember to switch between batteries when we are sitting / floating. Also, I forgot to mention that in order to turn the amp on for the sub the accessory switch on the dash has to be turned on.