Dual battery usage

[BARCHASER]

I've been reading some posts on this and I'm a little confused. I recently bought a North River Seahawk with dual bats, and I've never had them before. Yam 4strk mtr. This is the procedure I've been using.

Start and run with switch set to "both", idea being that while running this will charge both batteries.

When fishing (big mtr off), run the electronics using #1. Save #2, dont use it to run electronics to ensure there is always a fully charged battery. Switch to "both" before restart.

For storing or mooring, switch to off.

Does this work? Thank you for the help.

[boater]

i have never run my boat with both batterys on, i always run one at a time and alternate them everytime i use the boat to keep them both fresh.

[BiteFactory]

I alternate each trip too. When I first bought my boat I remember reading an intro story here about a guy who ran on both, had a good time out fishing in the ocean and ran them to nothing. Couldn't restart or call for help. He and his boat got picked up by a foreign fishing boat via a net and crane. That's how I remember it at least.

[ISeeFish]

What type of batteries, starting or deep cycle?

[WaterDog]

I have dual marine batteries (Trojan Group 27) and I also alternate between the two. I don't run them on "both". If the boat is going to set for any length of time I plug in the Guest charger so the batteries are fully charged. I can run the depth sounder/gps and the stereo/cd player for 8 to 10 hours and still run the blower and start the big block. When i get home the switch goes to "off".

[STGRule]

Alternate. That way you have a good battery for the emergency. That's why you have two batteries. And what Waterdog said. Land charging is a bunch easier that panic on the water. And he should know. That music is loud. :wink: I bet it uses way more battery than if it was just background music. :cool:

[BARCHASER]

Thanks. Sounds like the consensus is to alternate. Seems reasonable.

[Gundog]

I have dual Batteries on my seahawk I installed them myself. I use two battery switches, on switch is bat 1, 2 or all and the other is on and off. My starting battery is bat.1 I run all my electronics on bat 2. I can switch to bat 2 for starting if needed or put it on all for starting the second switch turns the electronics on or off. This way I don't have the voltage dip going to my electronics when starting the motor. I can also turn all power off by turning both switches to off. If I needed I can run electronics using the all position on switch one. I like having the double switches so I can just turn everything off when the boat is stored or in case of an electrical fire on board just turn both off.

One more thing I have a on board battery charger that charges and maintains the batteries, I just plug the thing in when I get home and it is always ready to go.
Mike

[Tinman]

I have two batteries on totally separate circuits. The main battery is used for starting the engine and running the bilge pumps and navigation lights. This is a "marine-starting" type battery that is charged by the outboard.

The second battery is in the console, and is used ONLY for powering the VHF, fishfinder, CB and other electronics. This is a combination starting/deep cycle battery that has no on-board charger. This gives the electronics a clean power source free of engine interference. The electronics draw very little power, so the console battery is good for days of use. I charge it manually at home.

Even though the two batteries never share the same circuits, they back each other up as follows:
* If the console battery dies, I flip a small (15 amp) transfer switch that powers the electronics from the main starting battery. The switch allows either battery to be used for electronics, but never both batteries at the same time.

*If the main starting battery dies, I physically remove the console battery, and move it back to the stern to replace the dead battery. I can still run the electronics with the aforementioned transfer switch.

With this system, I can't lose both batteries at the same time. As others have mentioned, it is risky to use the "both" setting on a conventional battery switch. On the "both" setting, you risk running down both batteries if the charging system fails, or if the engine becomes hard to start. I know darn well I would erroneously leave the switch in the "both" position, and get into trouble.

I also have a voltmeter on the console to check voltage on both batteries.