Wanting to add a second battery and a solar charger.

[coreyjohnson99]

First time posting here, thank you all for being a great resource. I just purchased my first sailboat, a 1979 Newport 28. It currently has one battery that is used to start a 9.9HP outboard, run the lights, bilge pump, and instruments. There is also a Batt 1, batt 2, both, off switch located in the battery area. The outboard does not charge the battery while it is running and the PO removed the atomic 4 inboard. The boat is on an inland lake and we use it mainly for day sailing and the occasional overnight.

I would like like to add a second battery so the first battery could act as a starter for the outboard while the second battery is used to power all the accessories. I would also like to add a solar panel <100w with a solar charge controller. In addition, I would like the solar panel to charge both batteries (keep them topped off). My question is how to go about wiring this scenario. The posts that I've read usually state the solar panel is used to charge the house, while the outboard or inboard's alternator charges the start battery, but this is not my case.

Should I use a VSR in this setup?
Should I purchase the Add-a-Battery by Blue Sea Systems and get rid of the old Batt 1, Batt 2, Both, Off switch?
Thank you for your insight and/or pointing me in the right direction.

 

[Tom J]

I had a similar setup to yours. An O'Day 23 with a 9.9 hp outboard and one battery that powered the house circuits. This was in the days before affordable solar power. I added a second battery, and I would run the boat off one battery until it got low on charge, then bring it home to charge and run the boat off the second battery. I only did day sails, and the outboard was a pull start.
In your case, I would keep the 1-2-both switch and install a second battery and the solar power. When the boat is not in use, the batt switch would be on both, keeping the batts topped off. Start the outboard on one batt, then switch to the other battery for the day. Ideally, the second batt would be a deep cycle, and the first would be a start battery.
Eventually, you might want to upgrade to a charging outboard, and an ACR, but for now, I think the KISS principle applies.
Good luck and welcome to the forum.

 

[Orbweaver]

if you scroll down on the main page you'll find the sub forum "musings with Maine sail". I believe the first thread will give you some great answers.

 

[Stu Jackson]

Should I use a VSR in this setup?
Should I purchase the Add-a-Battery by Blue Sea Systems and get rid of the old Batt 1, Batt 2, Both, Off switch?

Yes, it is a perfect candidate for the VSR - echo charger, combiner or BlueSea.

Don't buy that Add-a-Battery, you will regret it on a sailboat.

Here's some reading for you that comes from my collection at Electrical Systems 101 Electrical Systems 101

1-2-B Considerations (New 2020 - Rod finally got around to diagramming what I had done in the above link in 2009 )
1/2/BOTH Switch Considerations

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings

This is a newer primer for boat system wiring design with a thorough diagram: Building a Good Foundation (October 2016)
Building a DC Electrical Foundation

What are ACRs, Combiners & Echo Chargers? (by Maine Sail) [scroll to the top]
Battery Switch Question ? and Battery isolator / voltage regulator / batteries

Making Sense of Automatic Charging Relays (2019)
Making Sense of Automatic Charging Relays - Marine How To

Dumb Add-a-Battery thing:
AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries

Solar Systems: Selection, Installation & Controllers by Maine Sail SUPERB

Installing A Small Marine Solar System by Compass Marine How To

Do I Need a Controller for Solar?

Do I Need A Solar Charge Controller ??

 

[coreyjohnson99]

Thank you all for sharing these resources. I'll dive in and do some reading with the above links.