Should battery charger be on all the time?

Oct 17, 2011
2,809
Ericson 29 Southport..
Don't worry it, mate. In a short while all of these 'problems' will just be second nature. Starting out always has its obstacles..
 
Jan 4, 2006
7,230
Hunter 310 West Vancouver, B.C.
One Other Telltale ..................

Oh yeah, just seems overwhelming at times...
.................. is to keep an eye on the acid level in your batteries.

If you're leaving the charger on 24/7 and you need water much more than every 4-5 months (more in the summer - less in the winter), your charger may not be all that smart.

Try unplugging the charger on a regular basis to see if the water loss decreases. The decision to replace or unplug is yours after that.
 
Jan 10, 2015
130
. . Pensacola, FL
Sounds very reasonable...thx.

Still wondering about all this stray current stuff and being tied in to the marina electrical grid when shore AC is connected. Perhaps a galvanic isolator would be a wise addition to the onboard elec system. However, I get the impression from a comment by MaineSail that these might be insufficient.
 
Feb 26, 2004
23,015
Catalina 34 224 Maple Bay, BC, Canada
Any healthy battery, once fully charged, should hold its voltage for months. Recall those poor skippers in the frozen north who have to take their boats out of the water every year. They don't keep 'em plugged in and they do just fine.

It's a pretty good indicator of your battery condition if you leave it unplugged when you're not there and check the voltage.

If the voltage is drooping, either your bilge pump is working a lot more than you thought, or something else is going on that you need to investigate.

I'm a big fan of leaving my boat disconnected (except perhaps the night before I go on a cruise - which I do every week or two - and want to run the fridge 'cuz I've loaded up with food the day before and/or want to make ice.

Maine Sail is right: the SOLUTION is to unplug and get a solar panel. Avoids all that stray corrosion nonsense, or most of it unless your dock mates are electrical fools and your marina electrical system is crap.
 
Jan 30, 2012
1,140
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
Galvanic isolators are designed to trap up to about 1.2 volts DC which prevents your anode(s) from protecting the neighbor boat - thus wearing away your anodes and then your expensive underwater metals. Galvanic activity is normal and this is most common.

If the evil vampire voltage - called stray current - is produced by your neighbor's negligent wiring, failed battery charger, or etc., and if that voltage is greater than 1.2 DC volts a galvanic isolator will not protect your underwater metals. Stray current events are much less common than galvanic.

Obviously, if the evil stray current comes from your boat the isolator won't help at all.

A galvanic isolator is a very wise installation unless you unplug.

Charles
 
Jan 10, 2015
130
. . Pensacola, FL
Very good info...once again, I'm enjoying the education.

Now I need to get educated on solar panels and how they work with a battery charger...see, the more I know, the more I discover what I don't know :)
 
Sep 28, 2008
922
Canadian Sailcraft CS27 Victoria B.C.
Any healthy battery, once fully charged, should hold its voltage for months. Recall those poor skippers in the frozen north who have to take their boats out of the water every year. They don't keep 'em plugged in and they do just fine.
That only works in cold temperatures. The warmer the temp the more voltage battery loses.
 
Sep 28, 2008
922
Canadian Sailcraft CS27 Victoria B.C.
A galvanic isolator is a good solution. An isolation transformer is the best solution.
 

KZW

.
May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
I leave the battery charger plugged in. I don't have any solar cells. They are way down on the list of things to get. My reefer is running 24/7 and in the summer, the A/C is running. "Summer" starts in late March or April and runs through early October. In the winter, there is a heater running on a thermostat. The dehumidifier, and of course the bilge pump on Auto, is on year round. I try to run or sail the boat every weekend.

The charger is the 55 Amp model, OEM from when the boat was new. Last week on the boat, with nothing running (reefer compressor was off at the time) I checked the current to the batteries. It was 1.5 Amps and the batteries measured at 14.1 VDC, i.e. fully charged. Given the size of the batteries, and the low current, I don't see how it is going to boil off battery water. I check the water every month. Since Jul 14 I may have added less than a 1/2 to 3/4 cup total, and most of that was when I picked up the boat from the PO.