Charging trolling motor battery

[kanga2311]

I have a Glastron GS 205 FS with 5.0L Volvo Penta 55 LB MinnKota. I have 2 house/starting batteries (I didn't want to get stuck with a dead battery after fishing while using the radio), and a trolling motor battery. It's a pain removing the boat cover, opening the engine hatch, getting a 50' extension cord, attaching the battery charger to the trolling motor battery. I have heard about VSR's (voltage sensitive relays). Could I just connect the battery to the alternator? Maybe with a switch so it wouldn't charge until I want it to? How do other people charge their trolling motors when they go camping for a week or two without any power around? Any help would be greatly appreciated.

 

[Boatist]

Re: Charging trolling motor battery

With a 5.0L you probably have a 100 amp alteranator or at least 65 amps.
I would use a battery isolator (My Favorite) or a VSR or CSR type switch.
Any of these will automaticly charge the batteries any time the motor is running. Problem is deep cycle trolling motors batteries may take up to 15 hours to fully charge after a deep discharge. Most times your not going to run the motor that long to fully charge. If they do not get fully charged then the life will be shortened. So hook up one the above and make it eaiser to fully charge your batteries at home.
I use a battery isolator on my 65 amp alternator to charge both my batteries. At home I put a plug on the bow of the boat just under my cover. There I hook up my battery charger without takeing the cover off or getting in the boat at all. I still charge both of my batteries thru the same battery isolator. I also have a 8 guage wire from my truck alternator thru the trailer plug that I can also plug in to the same plug on the bow of the boat and charge the batteries going down the road. I do not use this very often but can when I need to.

For charging at home a on board battery charger that will charge all your batteries is a good option. All your need to do is hook up the entension cord to a external plug. The On board charger are automatic and will fully charge without over charging.

Camping for more than one day the best option is probably a portable generator. Either hook the ac up to a on board battery charger or hook the 12 volts dc up to the batteries and charge that way.

 

[kanga2311]

Re: Charging trolling motor battery

Thanks, lots of good ideas, I'm glad I posted. Not sure which way I'll go.

 

[rndn]

Re: Charging trolling motor battery

Second vote for the onboard charger. It is great to just reach under the cover and plug it in. Never have to worry about the batteries as they are always fully charged.

 

[sschefer]

Re: Charging trolling motor battery

My solution was the best of two worlds I think. I have two group 27, 265 RCA, deep cycle's up front for the trolling motor and a 24v 65lb trolling motor. I have a 800 CCA marine starting battery for the engine. I installed a Pro-Mariner tripple battery onboard charger and I have a 1000 watt Honda super quiet generator. The honda generator puts out adequate wattage to run the onboard charger which charges the batteries with up to 20 amps of current. This works even though the generator (actually its an alternator/invertor) only puts out 9 amps because the charger only draws 7 amps.

The generator system doesn't work without the charger as it only generates 9 amps and can only charge a single battery at a time without adding more circuitry to the system. Keep it simple is the moto here.

So far it seems to be working great.