So, are you supposed to leave your Boat Batteries plugged in 24/7 all-year long on the Onboard Charger?

[tcbass]

I've always brought my boat back to the garage and immediately plugged it into the onboard charger. I've always left the trolling motor and starter marine batteries plugged in 24/7 all year long, including during the winter with the boat in a heated pole barn or garage.

 

I've had 2 boats, one with a high end Dual Pro Professional Series and low end Minn Kota charger. 

 

Someone said that you shouldn't leave it plugged in 24/7 if the onboard charger doesn't have a 'maintenance/trickle' charge function. I just assumed that all newer onboard chargers had maintenance/trickle charge built-in but apparently not.

 

He said he brings his boat home, plugs it in until it's charged, about a day, then removes it. If he doesn't go out right away again he'll plug in the onboard charger the night before he goes out. 

 

Don't today's onboard chargers have maintenance/trickle charge feature and are meant to be left plugged in 24/7 all-year long? Even if it has a maintenance/trickle charge feature are you supposed to unplug it after it's fully charged?

 

So, are you supposed to leave your Boat Batteries plugged in 24/7 all-year long on the Onboard Charger?

[A-Jay]

Unless I using the boat, the Dual Pro is plugged in & charging.

365/24/7.

A-Jay

 

 

[Log Catcher]

It likely depends on the brand of charger as to whether or or not it has a trickle charge mode. I plug mine in as soon as I get back from fishing and leave it for several hours. I will unplug it over night and plug it back in the next day for a while. when I am going again I will plug it in the day before. In the winter I plug in the charger once every 2 or 3 weeks for a while. My boat stays in an unheated garage and so far this has worked out okay.

[Jig Man]

I always call the charger manufacturer and get their recommendations.  My current charger is a NOCO.  I was told by them that I shouldn't leave it on for long times unless I was able to shut off everything to the batteries.  I do have a master shut off and throw it when I plan to leave it on for an extended time.

[Way2slow]

First make sure the charger has a maintenance mode.  That can be a float mode or cycles on and off, based on preset voltages.  With all this "high quality" Chinese junk, if it goes into a float mode, you need to verify the float voltage.  If too high you don't want to leave it on 24/7.

 

Also, verify with the battery manufacture their recommended float level.  Charger manufactures have a tendency to exaggerate the numbers. 

[WRB]

If you have battery switch for the cranking battery it should off during charging to prevent current in the outboards electronics. Up plug the trolling motor when not using  the boat for weeks at a time. Check all the rocker or toggle switches including storage locker lights etc making sure they are off. Unplug or switch off your electronics, you don't want current to them when charging batteries. 

With all that said why leave a charger on for months? It's easy to periodically plug in the onboard to recharge batteries for a few hours and if they have been drawn down for some reason something was left on!

Do you really want to be on vacation or hundreds of miles from home and worry about a onboard battery charger malfunction?

Tom

[tcbass]

Update:

 

I emailed the big 3 marine onboard charger companies about leaving your onboard charger plugged in 24/7-365 and this is the response from Dual Pro, NOCO, and Minn Kota. I'm not shocked that Minn Kota said not to do it, they are the lowest quality of the 3 in my humble opinion. The other 2 said to leave them plugged in all the time.

Even if I left it plugged in I'd connect it to a 2,000 joule surge protector, although a 900 joule is probably fine, for $17 you can get a quality Belkin surge protector and it's cheap protection for your charger, batteries, and boat electronics. I also turn all of the boats breakers off when it's not on the water which should also protect the boats electronics.

 

 

Quote

Dual Pro:  

 

We do recommend leaving the charger plugged in at all times.  However, if you have wet cell batteries, please make sure you practice good battery maintenance. 

 

Thank you.

 

 

Quote

 

NOCO:  

 

Thank you for contacting NOCO support. Our chargers are designed to be able to be plugged in at all times safely. Once the battery is fully charged, the indicator on our charger will glow green and the unit will stop charging. Our intelligent battery maintenance technology continuously monitors the battery to determine when a maintenance charge should be initiated. If the battery voltage falls below its target threshold, the charger will restart the Maintenance cycle until voltage reaches its optimal state and then discontinues the charge cycle. The cycle between Optimization and Maintenance is repeated indefinitely to keep the battery at full charge. The battery charger can be safely left connected indefinitely without the risk of overcharging.

 

Thank You, 

 

 

 

Quote

 

Minn Kota:  

 

So the chargers can be left plugged in because yes they do have a trickle charge. As far as leaving it plugged in 365 days I wouldn't. If you are planning on taking it out and using it during those 365 days than charging back up when done that is fine. You want to make sure that you check the charger to make sure it is working properly every so often. Don't just leave it and not check it.

 

Thank you,

 

 

[Way north bass guy]

I plug mine in as soon as I unhook it from the truck, and unplug it the next morning when it’s charged up. Store the batteries in the garage in the winter and throw them on the charger once a month or so and I’ve had batteries last a good 10 years or so that way. I’m not sure it’s a great deal of help to be plugged in 24/365, seems like a waste of hydro to me and the way I do it, my batteries seem to fare quite well. I think the main thing is to not leave the batteries severely drained for any length of time, get em topped up as soon as you come off the lake and you should be fine. 

[tcbass]

Just now, Way north bass guy said:

I plug mine in as soon as I unhook it from the truck, and unplug it the next morning when it’s charged up. Store the batteries in the garage in the winter and throw them on the charger once a month or so and I’ve had batteries last a good 10 years or so that way. I’m not sure it’s a great deal of help to be plugged in 24/365, seems like a waste of hydro to me and the way I do it, my batteries seem to fare quite well. I think the main thing is to not leave the batteries severely drained for any length of time, get em topped up as soon as you come off the lake and you should be fine. 

 

 

AGM or wet cells?

[Way north bass guy]

Just good quality deep cycle wet cells, and a good wet cell starter for the motor/electronics. Also, keep an eye on the fluid levels every now and again but that’s about it for me.