Which setting for dual purpose battery

lrlima

Petty Officer 1st Class
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Oct 16, 2005
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223
Probably the easiest question of the day - but I have a dual purpose marine battery. If I understand it correctly, that means its both a starting and deep cycle battery.

My battery charger has a setting for both "deep cycle" and "normal" charging. Which one should I use to charge this battery? Sorry if this is a silly question but i tend to over analyze things....
 

Zackman

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Dec 3, 2005
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376
Re: Which setting for dual purpose battery

lrlima, dual purpose can have a few meanings... Can you tell us the battery manufacturer and model?
 

lrlima

Petty Officer 1st Class
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Oct 16, 2005
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223
Re: Which setting for dual purpose battery

thanks zachman. It says Duralast Dual Purpose Marine Battery.

Part # 27DP-DL

Marine cranking amps - 1000
Amp hours - 115
Reserve capacity - 180

I use it as a second battery to run the radio and gps / fishfinder.
 

rob711

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May 31, 2007
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232
Re: Which setting for dual purpose battery

someone will know more but i'd go with the lowest amp setting..i think its better for the battery that way...some one will chime in with a more in depth answer
 

WillyBWright

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Dec 29, 2003
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8,200
Re: Which setting for dual purpose battery

Dual Purpose batteries are deep-cycles that are capable of delivering cranking amperage for smaller motors. I wouldn't use one on anything with more than three cylinders, and not on any EFI of Direct Injected models as a primary battery. They still charge slow. Use the Deep Cycle setting and I wouldn't go over 10amps.
 

Big Keepers

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May 13, 2007
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Re: Which setting for dual purpose battery

The most effective way to charge and/or maintain a battery with a charger is slow and steady. A 2 amp trickle charge is fine. If you are having a problem and need some quick juice to get the battery going, then you can hammer it with a 10 amp charge but only for a short period of time. Do a search on batteries here and you'll find a lot of info on how to maintain your battery. There is no such thing as a "maintenance free" battery. All batteries should be checked periodically, especially the fluid levels, at least once a season, usually spring time. Pop the caps and see WITH A SMALL PEN LIGHT, NOT A MATCH OR LIGHTER, if the fluid inside is at the tops of the plates or slightly above. If not then boil some water, let it cool down to room temperature and add it slowly until the levels are up (boiling it distills it.) Also if you are going to charge a dead battery you should pop the caps off as it will create some heat and gases that you'll want to allow to escape. Do this in a ventilated place like your garage with the door or a window open. Every now and then you can look inside carefully and see if bubbles are coming up in the electrolyte. This means you're getting a good charge.
 
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