Battery Switches on if plugged into Shorepower?

Cregeis

Member
Joined
Feb 27, 2019
Messages
12
Reaction score
3
Points
3
Location
Greensboro,NC/ Morehead City, NC
Model
Freedom 335
Is it ok to leave your battery switches on if you are plugged into shorepower and have your battery charger on? I would like to run my refrigerator which is on my DC side so I have to turn the battery switches on for it to run. I would turn everything else off like the radio, Garmins, etc. Also, if it is ok, does it matter if the battery switches are on 1,2 or both?
 

wspitler

GreatGrady Captain
Joined
May 16, 2011
Messages
1,368
Reaction score
320
Points
83
Location
Inglis, FL
Model
Express 330
It is probably OK but need more information to be sure. Are we talking two engines one engine which is the house batteries most refrigerators are AC and DC and will run on AC preferably DC if AC is not present. Assuming your battery chargers are demand type all you need is your house battery powering the house load and the battery chargers on if they are hooked up to all your batteries should be fine. But you have not provided enough information to make a definitive analysis.
 

Cregeis

Member
Joined
Feb 27, 2019
Messages
12
Reaction score
3
Points
3
Location
Greensboro,NC/ Morehead City, NC
Model
Freedom 335
I have a new 2021 GW 335 with twin engines and the standard battery charger that comes with the boat. The refrigerator breaker is on the DC side only. Thanks for your help!
 

seasick

Well-Known Member
Joined
Aug 19, 2008
Messages
9,563
Reaction score
1,434
Points
113
Location
NYC
It is generally OK to leave switches on. You only need to leave the house battery on . Turn on one switch to see if the fridge gets power. If not, the other switch controls the house loads.
Assuming you charger is a decent smart model, all should be fine.
One negative of leaving shore power ON ( any shore circuits, either 120v AC or DC) is that there is a greater chance of damage from a lightning strike. Of course that is always a risk, it's just a little greater since a power surge can travel through the shore power service.
 

Fowl Hooked

Well-Known Member
Joined
Jun 4, 2007
Messages
216
Reaction score
59
Points
28
Location
Southern Maryland
Model
Express 265
I also run my DC only fridge pretty much all of the time on my 2005 265 Express and so I leave the switches on while in the slip and on shore power. I did replace the original onboard charger years ago, I don't recall the model but it was a 'smart' charger. Have been doing this for quite a few years now with no issues to date.
 

SkunkBoat

Well-Known Member
Joined
Oct 12, 2017
Messages
4,521
Reaction score
1,619
Points
113
Location
Manasquan Inlet NJ
Website
www.youtube.com
Model
Express 265
You have a DC only refridgerator? You are sure it is DC only? I ask because I know a guy who didn't know his fridge would run on both for 2 years.

Do you want the refridgerator to always run on dock power even when you are not there and run on battery when you are underway?

A better permanent solution is to set up an inverter to run the fridge when on dock power and switch to 12V House power when underway.

Its not ideal to be running the fridge on your battery charger for long periods. They are designed to charge batteries not to be a 12V supply.
You want your batteries to charge.
 

Beyond A Wake

Well-Known Member
Joined
Jan 23, 2022
Messages
238
Reaction score
43
Points
28
Age
73
Model
Freedom 335
The fridge is dc only . Yes you can leave dc side on just as you do when running with generator on. The chargers are smart and even if on with gen and motors running it will sense that no charging is needed. keeping it on is only way to keep fridge cold. I can't do it since I'm dry stacked, it is a pain when fridge takes long to cool down so it becomes almost useless compared to bags of ice.
 

drbatts

Well-Known Member
Joined
Nov 30, 2008
Messages
894
Reaction score
192
Points
43
Location
CT
Model
Express 305
Yes, its ok to leave the battery switches on while on shore power to use the fridge. I did it for years with my previous 265. Just keep in mind that if you lost power, or the cord gets unplugged, you will drain your battery(s) as well as defrost the fridge. Which happened to me a couple of times.
 

everwhom

GreatGrady Captain
Joined
Sep 1, 2015
Messages
446
Reaction score
81
Points
28
Location
Cape Cod and Nantucket
Yes, its ok to leave the battery switches on while on shore power to use the fridge. I did it for years with my previous 265. Just keep in mind that if you lost power, or the cord gets unplugged, you will drain your battery(s) as well as defrost the fridge. Which happened to me a couple of times.

x2 - I wouldn't do this at my marina, because I've had the shore power shut off on my boat randomly at times, and I'd hate to have my house bank run down to zero.
 

Fishtales

Well-Known Member
Joined
Jan 31, 2005
Messages
8,075
Reaction score
1,300
Points
113
I always leave mine on (15 years). Never an issue but I never lost power for an extended period. I like cold beer when I arrive!
 
Last edited: