Thread:

Onboard Battery Charger?

Just wanted to see what people are using for onboard battery chargers, i.e. what brand? happy? unhappy? what would you do diff if you could? I have 3 deep cycles in my Cobra, one starting/deep cycle and the other two on bank #2 are marine deep cycles for stereo use when the engine is off. All three batteriers are Interstate group 27's.

I want to put a battery charger on my boat and have it so the shore power plug is in the intergrated swim step platform so its easy to plug in with out having to raise the engine hatch.

Originally Posted by millhouse961

I have this one:
Products :: Battery Chargers :: ProSport 20 Plus Gen 2

Works great; connects to 3 separate batteries, when I get home, just plug it in and never had an issue. Worth every penny

I have the same brand but the 2 channel version. Works great

Originally Posted by Beer:30

I have the Pro Mariner 12, 6 amps x 2 banks. Two batteries (stereo) on one bank and starter battery on other. All three are Optima BlueTops. Going on SIXTH season now.

What I have learned is - you only need the MINIMUM charging amperage per bank. If there is a ONE-amp per bank model - that's fine. Here's the reason:

You run your stereo all day at the lake, draining that "side" of your batteries. You start up and run across the lake a few times in between - thus charging (mostly, if not completely) those batteries again. At most, you run the stereo some more and then ultimately, you drive the boat back to the launch ramp. You idle around there for awhile and then put it on the trailer. So, all of your batteries are mostly - if not completely - recharged.

Now you park the boat. They are already mostly charged, so they don't need much at all. Even if they are only 50% charged, a 2-amp charger would easily top them off overnight. I don't know about you, but I have NEVER come off of the lake with dead batteries.

So, you need a "maintainer" more than you need a charger. Pick whichever brand/model you want - just don't spend money for a lot of amperage. The high amperage is for bass boats that come off of the water with dead trolling-motor batts.

Marine Battery Chargers | ChargingChargers.com

I have one of the chargers that starts at 20A then when the batteries become more and more charged slows down the amps, so it starts at 20, then 10, 5, 3, 1. When I pull my boat off of the lake I plug it in and the most that I ever see it at is 5 but usually 3. I don't have any stereo in this boat, I pulled it out of my old boat before I sold it which had a big stereo.

i use a minnkota 3 bank 10amp per channel on board charger. got it from bass pro, i think it was under $300. i used the same one on my fishing boat for years with no problems. ive found with my boat it does use the 10amp rating for several hrs after i return home from the lake, but i have apx 5-6000watts of power for my stereo system and like it loud. it is very nice to just plug it in and forget about it.

Originally Posted by HOTRODREDNECK

i use a minnkota 3 bank 10amp per channel on board charger. got it from bass pro, i think it was under $300. i used the same one on my fishing boat for years with no problems. ive found with my boat it does use the 10amp rating for several hrs after i return home from the lake, but i have apx 5-6000watts of power for my stereo system and like it loud. it is very nice to just plug it in and forget about it.

I want to do another one but have about 400 projects to do before I do another big system in this boat.

Originally Posted by millhouse961

I have this one:
Products :: Battery Chargers :: ProSport 20 Plus Gen 2

Works great; connects to 3 separate batteries, when I get home, just plug it in and never had an issue. Worth every penny

Millhouse: Did your 270 come with it installed from Cobra or did you do it later? I was looking at the same charger you have cause i can get it from West Marine down here with a discount. I would need a 3 bank system as well.

I was gonna call Hernando over at Cobra today and see what they use over there. When i was in there 2 months ago he had quoted me about $500 for the charger and install with the shore power plug installed in the upper portion on the side of the swim step. Seems like a pretty easy install that i could do myself, i just get real nervous drilling a hole in my boat.

Originally Posted by Beer:30

You don't need a 3-bank system. Like me, I assume you have 3 batts. Two for running the boat when the key is off and one for reserve-starting. The two that are hooked together are just ONE large battery, in essence. If you had a three-bank charger/maintainer, the two banks hooked to the two "stereo" batteries would become one channel anyway, since those batts are not isolated from each other.

For instance, my TWO stereo batteries have ONE of the charger banks hooked to them. So, at full charge, those two would see 3 amps a piece of the 6 amps in that bank. Still more than enough to charge overnight.

You could have as many batteries per bank as you want. If they are hooked together, they are ONE battery with a lot of reserve power.

Remember, your alternator is only one bank. When you are underway, it is charging ALL of your batteries. If you needed one bank of charge PER battery, you would have THREE alternators.

Ya i see what your saying Beer:30, i just called Cobra and they said the same thing. All i need is a 2 bank system since the two stereo batteries are on the #2 switch which i turn to when the engine is off and im playing the stereo. When i start and run the boat i turn the switch to ALL so im charging all the batteries even though i wasnt draining my starting/deep cycle batt on the #1 position. All three batteries are new Interstate deep cycles with batt #1 being a marine starting and batt. #2 & #3 deep cycles.

As i was typing this Jeff from Cobra called me back and said they use ProSport chargers there.