Charging batteries

[NAGORSKI]

I have 2 trolling motor batteries and an on board charger,also some lights are hooked up to the batteries.The on board charger is connected to the 3rd battery for the motor also. I hate disconnecting the 2 trolling motor batteries and getting them out of their compartments each time I need to charge them. My question is, can I leave everything hooked up to the batteries and just hook up the charger to the battery and plug in the charger? Or will this fry my electronics?

[Down Deep]

I assume you have a 3 bank onboard battery charger. To avoid frying any of your electroncs and trolling motors you can install a two or three battery switch and shut off all power to any accessory. You would wire the battery charger behind the switch. Any store that sells marine equipment will have these switches. They are very easy to install.

[walleyewild]

On board chargers are made to be connected full time, they won't fry your electronics. if you're running a 24 volt system for the trolling motor you can hook both sets of leads from the on board to those batteries.

As long as you don't leave anything powered on that is connected to the starting battery I wouldn't worry about hooking that battery to the on-board charger. the alternator on the main motor should keep that charged and if you do need a boost on the starting battery you always can use a regular charger for that.

[NAGORSKI]

My charger is a 3 three bank charger I think. It charges the 2 trolling motor batteries and the cranking battery while the engine is running. The charger I want to use is a 2-6 amp battery charger that plugs into the wall. I use this to fully charge the trolling motor batteries because the on board charger just keeps the charge up,"keeps you on the water longer." When they are dead I use the regular charger and want to leave everything hooked up, can I do this?

[walleyewild]

I don't see why that would be an issue, 12 volts is 12 volts as long as you don't reverse the leads. If you're worried about the onboard dc charger getting fried it is handling the current flow from the alternator from the motor and most ac chargers only put out 10 amps, I believe my 40 merc puts out 16 amps so you should be safe. You can always check the manufacturer's web site and see what the spec's are for the dc charger that is installed in your boat.

[NAGORSKI]

So go ahead and leave everything hooked up to my batteries,trolling motor, on board charger,lights,ect,and use a regular battery charger that plugs into the wall and connect it to the battery and it should be fine?

[Jeremy airjer W]

I leave my stuff hooked up while charging with a plug in charger (its only the starter the trolling motor the depth finder and a 12 volt plug in). There shouldn't be any problem with this. I do this on cars everyday. With the newer vehicles there can be a lot of sensitive electronics. 12 volt electronics will have a range of voltage that they will operate on. lets say most will operate until the battery gets down to 9-10 volts and will not be damaged unless voltage is higher that 15.5+ volts.

by the way I saw your pic in the outdoor news, nice fish!! The avatar looks a lot better too!!

[NAGORSKI]

Thanks Airjer!

I'll give it a shot and hopefully I won't burn the boat down! This is gonna be a lot easier than pulling the batteries out from under my counsels each time.

[78cj5]

I was told when I bought my boat to always unplug my Minn Kota 70 (universal sonar, auto-pilot, co-pilot) before I plug in the on-board charger. I've made it a habit whether it is neccessary or not.

[NAGORSKI]

I'm not charging the batteries with an on board charger. The charger is a regular battery charger that you plug into the wall. By unplug do you mean unplug from the receptical or disconnect from the battery? Because I do unplug the trolling motor from the receptical on the wall of the boat, but I want to leave it hooked up to the batteries.As well as the on board charger and lights. Then connect the battery charger to the battery and plug the charger into the wall.

[78cj5]

Unplug from the receptical, not detatch from the batteries.

[BigWadeS]

The one thing to be careful of is ventilation. When the temp goes up be very careful, with high/humid temps the fumes from the boats gas tank and line can hang around and can make things very nasty if you get a bad connection from the charger, one little spark and booom....every year it seems like mulitple people burn down their garages, houses, and boats, because of this exact thing....

[NAGORSKI]

O.K. I think that makes me wanna just unhook everything when I charge the bateteries! Don't want that to happen.

[castmaster]

just make sure to leave the hatch open. it wouldnt hurt to open up the access to the bilge area if you have one just to let things air out a bit.

also, if you have your graphs powered off a battery your going to be charging i'd disconnect the power from the back of the graph before turning on the charger. same goes for any other electronics.