# How to charge a boat battery properly?



## LazyBones

I have two batteries in my boat, they are use for my trolling motor, fish finder, and live well pump. One is a marine/rv deep cycle, the other a marine dual purpose. What is the proper way to charge them. trickle or fast charge. they are both new this year.


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## leeabu

I don't like either of your choices. You want a 10 to 12 amp charge. A trickle charge (usually 1 to 2 amps) should be used for maintaining a battery like in the winter. A fast charge (usually over 15 amps) can boil the water our of the battery and warp the plates.


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## freyedknot

i would use a fully automatic charger thats made for marine batteries. 10 or 12 amp is fine.


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## Nikster

Your going to get 3/4 different opinions on what to do & what not to do. Here is a link, go to it & find out yourself in how to charge a battery & what to do. Then make a decision. I've been doing it that way for years & get the most out of my batteries. Oh, & then some one will comment on that one should NEVER leave a battery on a cement floor. Which was the case years ago & some will even stand by that rule. When I take out my 3 batteries, I store them on a shelf under my work bench & use a 'FLOAT CHARGER'. Float chargers are about 6,7 $$. 
When ever I take a trip I have a 3 bank charger & it takes about 10/12hrs., to charge them back to snuff. I'm NO tourny fisherman so I don't need a quick charge for them, nice & easy is fine.
Again go to Battery Info & everything you need to know is there, 

Nik

http://www.batterywholesale.com/index.html


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## roger23

https://www.pacificpowerbatteries.com/batteries.html


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## Bill-H

i have a battery charger on board it is 4 amp that charges the batteries up in no time at all.


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## LazyBones

Thanks for your help again, I do have a 10amp-2amp automatic charger. It looks like i can use either one.


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## carterfish

I have always heard that you should run your battery totally dead before charging it, to improve the longevity. BUT, I have had my battery for five years, and never ran it dead, and used a 2 amp trickle charger. UNTIL my buddy left it on a 40 amp charge for 8 hours, and killed her last week.


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## CARP 104

I have a couple automatic chargers I got a few years ago at batteries plus. It lets you select whether the battery is deep cycle, regular...etc and you can pick 2, 6, or 10 amp charge and it will charge the battery accordingly.


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## mjgood

ni-cad should be ran dead before charging but these are usually smaller batteries. Most deep cycle batteries can be charged dead or not.


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## grdhandyman

When I am finished for the day, I always put mine on trickle chg (2a) and leave it. Have never had a problem and it has a full charge for the next time.


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## Snackmans Dad

What's the theory behind the cement floor and batteries?


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## UFM82

Batteries should not be stored on the floor as they will discharge. 

OK, that statement WAS true 100 years ago when battery cases were made of wood. The electrolyte would seep through the wood and provide a pathway for current to follow and it would discharge into the "ground". Ever wonder where that term came from? Yes, it meant "ground" as in the Earth. That is why you stored batteries on an insulated shelf to prevent the self-discharge. 

Modern batteries obviously don't use wood so that old saying holds no water anymore. In fact, it never fails to amaze me when a guy will say to never store a battery on cement ( which is a great conductor???) will then put it on a STEEL shelf that is sitting on, you got it, a cement floor. LOL 

The only reason to not store batteries on the floor anymore in this day and age is to prevent them from freezing in the winter. If you remove them from your boat, chances are you put them somewhere near the garage door on the floor or a shelf. It'll be the coldest on the floor. Letting them be in the coldest area of the garage is bad as a frozen battery is ruined. The ice will warp the plates and short it out. Discharged batteries freeze easier than fuller charged so keep them on a trickle charger or maintainer over the winter and they'll be fine. 

So, the old saying is just that- an old saying. Don't worry about it anymore. 

UFM82


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## Snackmans Dad

I was just wondering on the cement floor thing, I side with you on that matter. I have had some interesting talks on the subject, really rattled some cages when I would ask someone to explain the threoy and they could'nt. "The volts just jump out" was usally the best one.


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## JimmyZ

I have a 5amp dual pro. When I'm done I just plug it in and let it go. Charges 2 batteries seperate from one another. I leave it plugged in 24/7. It automatically shuts off and has indicator lights that turn green when charged. The battery I crank the motor with, I let the motor take care of that. Never have had a problem.


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## bassmanmark

I have a 35amp and a 30amp Vector and it charges my Optimas in just under an hour...full charge. Had my Optimas going on the 4th year with them and I fish roughly 85 days a year on them. Never had a problem with water boil and I doubt I ever will.


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