Boat battery chargers

mojokoko · Post by **mojokoko** » November 15th, 2004, 12:09 pm

Anyone know a good way to charge boat batteries? Or is there a "Boat Battery Charger" I can pick up somewhere?

Post by **wevans** » November 15th, 2004, 12:36 pm

West Marine
http://www.westmarine.com/webapp/wcs/st ... ctId=27385

Post by **Sir reel** » November 15th, 2004, 12:52 pm

OK... it's time to educate me (at least give it a try

). What are the benefits or advantages of installing a unit such as this?

My antiquated understanding is based on: .....

1. Outboards charge batteries when they are running.

2. I have a battery selector switch which allows me to draw from 2 batteries or (and I assume) charge back 2, with engine running.

Thanks.

mojokoko · Post by **mojokoko** » November 15th, 2004, 1:00 pm

I have the same setup as you. But my batteries have ben low. I assumed that if I set the switch on ALL it charges it while running. But a couple of timens I forgot the trolling motor was on and I think it drained a lot of the power from the battery. Because I can tilt the motor on battery 2 and while it's on all but if I change to 1 it will not tilt the motor.

Post by **Sir reel** » November 15th, 2004, 1:05 pm

Thanks for your input "mo". For the sake of disscussion and any future replies.... lets assume that in "my" scenario both batteries are the same age, strength, etc.

Post by **wevans** » November 15th, 2004, 1:36 pm

You can only charge ONE battery at a time with the motor, if you charge both it will put a continues load on the charging system and kill it eventually

when useing the battery switch, I will run on one battery for a while and then switch over to the other "unless I'm trolling a lot" then I just leave it on the trolling battery so that it is being recharged will moving

The only time I use the both is if one is dead, I then run the motor long enough to crank on the dead one and switch to the one that needs charging "ALSO, NEVER SWITCH WITH THE MOTOR RUNNING"

The onboard chargers are a conveniance more than anything, I seldom need anything other than the boat motor for my batteries

If you just need to top off a battery from time to time, a small 6 amp portable "around 20 or 30 bucks" is all that is needed

Have I totally confused ya now

mojokoko · Post by **mojokoko** » November 15th, 2004, 2:04 pm

So "ONE" battery can be charged at a time. So if I turn the dial to the Trolling battery while it is running it is charging too?

Post by **wevans** » November 15th, 2004, 2:15 pm

The motor will charge whichever battery it is switched to at the time

dstockwell · Post by **dstockwell** » November 15th, 2004, 2:22 pm

Not sure bout swirching while running, shut down switch over. I usually run out on one and back in on 2. Both get used an charged, but I still have one of these just in case.

Post by **wevans** » November 15th, 2004, 2:28 pm

This can not be stressed enuf

"NEVER SWITCH WITH THE MOTOR RUNNING"

Post by **dbplug** » November 15th, 2004, 2:50 pm

I have one of the Guest chargers that Wevans referenced on board for my two battery 24V trolling motor set up. All of my electronics and accys. are on a separate cranking motor. I figure if I have to switch batteries around on the water in case of an "issue", I can do it.

I have been very happy with the guest, no worries. Be sure you install a circuit breaker.

I have not had to charge the main cranking battery yet. The Yam 90 seems to be doing an adequate job of keeping it charged. But then I only have 90 hours on the boat and motor.

Post by **tin can** » November 16th, 2004, 7:45 am

DB has the right setup. Install separate batteries for cranking and your trolling motor.

Wevans is right, don't switch batteries with the motor running.

if you have a dual battery system and switch for cranking/electronics, DS is correct(I can't believe I said that). Run out on battery 1, run back in on battery 2. This keeps them both charged.

Now, to the original question.

If your boat sits for a couple of weeks between uses, you need to occasionally charge your batteries to bring them up to full charge. If you don't, they develop a memory for the weakened condition. It isn't noticable for a while, but you'll see you are buying new batteries more often. If your boat is equipped with a volt meter, check the voltage from time to time. A fully charged 12 volt battery actually produces around 14 volts. As for your trolling motor batteries, hook the charger up as soon as you get home after every trip. Deep cycle batteries are designed to be drained and recharged. If you don't charge them after every use, you're cutting the life of your batteries.

The onboard chargers are the way to go. There are a variety of onboard chargers for different applications. there ar one bank chargers, for single batteries, or up to a four bank charger, for charging several batteries. The multi bank chargers have isolators, to allow you to charge multiple batteries, without bleding from, or to, other batteries on the system. You cha do the same job with a portable charger. I would recomend at least a 10 amp AUTOMATIC charger. These chargers are designed to be hooked up and left on. The automatioc chargers won't over charge your batteries.

The ideal solution is the onboard charger. Hook it up once, mounted in the boat. When you get home after every trip, plug it in.

Have I muddied the water enough?

mojokoko · Post by **mojokoko** » November 16th, 2004, 8:59 am

Thanks for all your help. So if I run out on 1 and then come back on 2 would that charge 1 since 2 would already be charged?

Post by **Sir reel** » November 16th, 2004, 9:38 am

Thanks to everybody who participated in this thread. Good information all around.

I should have indicated that I don't have a trolling motor and my 2 battery system is comprised of 2 cranking batteries. The one thing I didn't know before is the caution mentioned about having the battery selector set on "both" and being unaware that the strain on the outboard charging system would be too much over an extended period. Again, Thanks for educatin'n Bud.

I was already aware of the rule on "don't switch the selector while the motor is running". OK.... can someone tell me WHY?

None of the material I've read explains this....it only says "don't do it" .

Post by **tin can** » November 16th, 2004, 4:08 pm

Bud, when you move the selector switch with the motor running, it actually breaks the circuit for a split second, then instantly doubles the load. Things tend to get hot.