Charging batteries

[mawi97]

When do you plug in your boat? When you get home or before you go? I am fixing to purchase two new batteries and want to get the most out of the charging cycles while saving the battery life as much as possible. I always have plugged it in the night before. Does it hurt to leave it plugged in?

[twise7]

I think in the warmer months it's just personal preference and I plug my charger in when I get back from fishing. I check it the next day and unplug it if it's done charging. One piece of advice that might be a "no brainer" to some but was new to me, is you need to fully charge each battery with a regular car battery charger BEFORE you put them on your 2 or 3 bank charger.

[air1lch]

I keep mine on 24/7. When I hook up I know my 24v troll and the cranking batt are fully charged. When I get home, just plug it back in and leave it plugged in until I take off again. It's not good to let your batteries sit less than 100% because this allows sulfate deposits to build up on the lead plates in your battery. This is especially critical in winter or colder temps. I'm assuming of course you have lead plate batteries. Also, if you let your batteries sit without a charge, you will be constantly re-charging to get them back up, thus increasing the charge cycles. A battery can only take so many charge cycles. I'm also assuming you have a good marine charger that charges at various volt levels so as not to "over-charge" your batteries. Your better marine chargers will bring your batteries to full and maintain them thus minimizing sulfate build up and decreasing # of charging cycles. Caution: Most garage and automotive type battery chargers are bulk charge only, and have little (if any) voltage regulation. They are fine for a quick boost to low batteries, but not to leave on for long periods. As long as you have a good marine battery charger, you will be fine to leave on constant charge, but if you're unsure I would check the manual or google on-line to make sure. I have a 3-bank Pro Marine charger and it is one of the best investments I ever made for my boat. Been doing the job for nearly five years. Hope this helps.

[mawi97]

I have two on board chargers, I think they are actually Pro Marine also. I'm not at the house and would have to look. I think the existing batteries are 3-5 years old and probably are just in need of replacement. I know I have used them A LOT since buying the boat two and a half years ago. Thanks for the input.

[ironhead70]

Only when i go to a lake and stay close to the ramp ...other than that never...www.stayncharge.com

[sweetwater]

We have 2 huge deep cycles in the boat. No matter how hard we use them that day, we'll put the automatic onboard charger on 2 amps and walk away. Sometimes it takes 3 hours, sometimes 8 hours to fully charge, but its very easy on the batteries.

air1lch is right about the voltage levels, a constant amp charger is much better than a constant voltage charger. A constant voltage charger will overcharge at first and undercharge later.


Regardless of how you accomplish it, two of the keys to getting good service and a long life out of your batteries is keeping them fully charged and protected against temperature extremes as much as possible.

[R19]

As soon as I get home I plug in my on board charger. I unplug them the next day or as soon as I see them fully charged. I have a 30 amp 3 bank 10amps per bank charger which will do my cranking battery and both my trolling motor batteries. Charge time will vary from a couple of hours to 10 hours pending how much I have drained my batteries.

Heat is very hard on a battery. In the summer/hot weather months if my boat sits longer than 10 days I will charge my batteries even if I have not used the boat. Normally they will be full within 1 hour. In the winter/cool weather I will charge them if my boat sits longer than 3 weeks.

Regardless of when or how you charge your batteries it is very important that people check the water level on a regular basis. Low water will create heat while charging and heat is the number one killer of a deep cycle battery. A good deep cycle charger will charge in stages. Stage 1 will be a low amp charge for a small period then increase to a high amp bulk charge, that is followed by a low amp charge. Then the final stage will be a trickle charge.

[Colbyt]

Other people other places convinced me that a battery tender type of charger that you never disconnect is the better way to go. Hook them up as soon as you get home and leave them connected.

Whether they were right or not won't be determined for a few years.

[Ddot]

I leave mine plugged in 24/7