Adding second battery, 1,2 combo switch and ACR

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windsurfmt
Just Enlisted
Posts: 11
Joined: Sun May 10, 2020 6:38 pm
Sailboat: MacGregor 26M

Adding second battery, 1,2 combo switch and ACR

Post by windsurfmt »

Hey you DC wizards,
I'm adding an auto pilot (thanks for the help Boat) and with that a second battery, on off switch, dual bank battery charger and maybe an ACR.
I've searched old posts and can't find exactly what I need so here goes (grateful for any help):

!. I'm running the charger straight to the batteries, heard that was best.

2. Would like the second (house) battery to be dedicated to the auto pilot, at least until I know how much juice it uses in an average day. I'll be back in a slip most nights to recharge.

3. Not sure how to wire all this and if I should add fuse blocks, terminal blocks etc. At the moment the only things using DC are lights, GPS/fish finder, auto pilot and starter. Last season the lone battery ran everything and I motored enough that the battery never seemed to run low. Would like to keep it as simple as possible while still being reasonably safe.

4. Thinking about adding an ACR. I've diagrams that have it running right off the battery and others show it through the switch, thoughts?

5. Any one have a diagram that might help with all this?

I'm in Montana and our super short sailing season on Flathead Lake if finally about to begin...
Thanks all...
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Russ
Admiral
Posts: 8299
Joined: Thu Oct 11, 2007 12:01 pm
Sailboat: MacGregor 26M
Location: Bozeman, Montana "Luna Azul" 2008 M 70hp Suzi

Re: Adding second battery, 1,2 combo switch and ACR

Post by Russ »

Here's what I have and it has worked great. Simple and how it came from the dealer.

1 Dedicated battery for the motor.
1 Dedicated house battery.

The motor has its own battery and that's it. Nothing else on that one. That way whatever I do with house power, I can always get back home.
The main panel is connected to house battery via fuse at the battery terminal, with ALL DC power needs (eg: autopilot, cooler, DC outlets, washdown pump).

A/C battery charger is direct to both batteries (although I have no dock power in the slip)

Also have an ACR, which when under power will combine and charge BOTH batteries. Under power, the house side is never draining the house battery as the motor is providing power for everything.

I don't have a combo switch. First boat without one and I don't miss it. The ACR does everything automatically.
I do have a portable jumper pack just in case. Never used it, but have loaned it to others with dead batteries.

Others might chime in, but I doubt the Autopilot (I don't have one) uses that much power.

I just floated "Luna" last week and she's comfortable in her slip on Canyon Ferry. I MUST, one day, come up to Flathead. It looks spectacular.
Short season indeed. Although we have had some amazing Septembers in recent years.
--Russ
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Todd
Engineer
Posts: 154
Joined: Thu Nov 19, 2015 8:43 pm
Sailboat: MacGregor 26M
Location: New Mexico

Re: Adding second battery, 1,2 combo switch and ACR

Post by Todd »

Sorry for the delay in replying. Hope you are still on the forum and have your boat. I have the older version of the ACR and last fall reinstalled the dual battery set up with the battery selector switch. I also installed the battery maintainer from blue water yachts and shore power so we can start marina camping more. PM me and I can share my setup. Flathead lake...also on my list of places to go.
Todd
'07 26M

:macm:
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