dual battery question (2007 yamaha sx230ho)

[txav8r]

If all you do is run stock electronics and never have radio or lights on when the engines aren't running, you won't need to recharge. However, batteries only absorb 10-15 amps per hour. So if you discharge a batter playing music on a stock stereo for a couple hours, you will still need approximately an hour of cruise to recharge them. Everybody is different, but chances are, you use more reserves than that, and you will need to charge your batteries after use. Battery maintenance is one of the most neglected maintenance items in boat ownership. In a perfect world, batteries would never be in a depleted state even one night. Hope this helps.

 

[grady dagenais]

I think this matches what was posted and the way I plan to run my setup so that each one runs the whole boat - essentially creating a back up system - (1) is primary but if I ever need it - (2). Since 1 gets power/recharged from running, (2) will have the solar charger on while under cover to maintain its charge. May alternate which one gets the trickle charger through the summer with quick disconnects.

Both come in the house for the winter.

What would it look like if I wanted the tender to trickle both batteries - a diode on the + wires to prevent backflow to the charger?

I know that if I had the switch in the both position that the charger would do both but kind of defeats the purpose of that.

 

[Gray]

To boot onto this thread (and thank you to txav8r for his expertise), I am planning to run a Raymarine Quantum 2 Radar with an Axiom 9 MFD. My power system will include 3 each Odyssey brand 34M-PC1500ST-M batteries, in conjunction with a Blue Sea Add-A-Battery Kit ( https://www.bluesea.com/products/7650/Add-A-Battery_Kit_-_120A)

One of the Odyssey's will be the engine battery; the other 2 will serve as house/Navionics power.

I welcome any critique or troubleshooting.

 

[txav8r]

@grady dagenais Sounds like you are running a simple 1/2/off switch. Just remember, a battery never used won’t be your reliable backup. So swap batteries either 1 going out and 2 coming back, or 1 this weekend, and 2 next weekend. However you want to do it. Just get equal use on them.

@Gray , hope the schematic helped. Your battery bank setup is very similar to mine. Except I had only two group 27 I believe they were, AGMs. The add a battery switch will combine the banks, so having three similar batteries is good. Except the two you have as house batteries will be twice as many amps wired parallel, as your start battery. When in use, without starting engines, you will be depleting he house batteries, but once the engine charging system ramps up, it will close a relay, and all three will be parallel. This is good, because the engines will then charge the weakest first. There are variations to the setup to isolate them so you can always use a shore charger without combining.

 

[Gray]

@Gray... This is good, because the engines will then charge the weakest first.

Thank you sir.