deep cycle battery?

alabamadawg

Seaman Apprentice
Joined
Jan 19, 2010
Messages
31
What does the deep cycle battery do as opposed to the motor starting battery. Am I going to need both kinds of batteries to start the motor and then use the other electronics on the boat?
 

Fl_Richard

Lieutenant
Joined
Jan 21, 2005
Messages
1,428
Re: deep cycle battery?

No.

You didnt mention the vessle type and size but on anything under 18-20' a single battery is standard. Of course it never hurts to be beyond standard.

Now if youve got an electric troller, crank the tunes or fish for 9 hours with a 2kw sonar transducer and the motor off all bets are off.

Larger vessels have a starting battery that's connected to the engines and a house (deep cycle) battery that's used to run everything else. This is a great set up for most boats as it provides redundancy for a dead battery.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: deep cycle battery?

Why did you make another thread about this? The starting battery does what is says it does, it is good for starting the engine, and running the normal stuff while under way. The deep cycle batteries are made to run things like trolling motors/lights/fish finders/etc when the engine isn't running. They are able to be drained down and recharged without causing damage to the battery. The starting battery can run those items, but for less time and it will damage the battery if it is drained repeatedly.
 

alabamadawg

Seaman Apprentice
Joined
Jan 19, 2010
Messages
31
Re: deep cycle battery?

sorry, thanks It's a 17ft....the electronics are just the fish finder, trolling motor on occasion and the trim for the motor...
 

TerryMSU

Senior Chief Petty Officer
Joined
Jul 31, 2007
Messages
743
Re: deep cycle battery?

I disagree strongly with Richard above. even for a smaller boat, two batteries are preferred if you have a trolling motor, and especially if you have anything else (Radio, extra lighting, fish-finder). The only exception to that would be if you can pull start your motor. Being as yours is an 80HP, I suspect that is not the case. Otherwise, I use a starting battery for marine functions (this assumes that your motor has the capability to charge the starting battery, otherwise use a separate deep cycle for that also.) Otherwise, you will find yourself in a no-start situation.

As far as which deep cycle, "How much are you willing to spend?" First choice is to get an AGM battery for longest battery life (in terms of how many charge discharge cycles, how well it holds a charge, and how well it tollerates the vibration of a boat.) Get the biggest one that you are willing to deal with weight-wise and dollar-wise. If you can go for the AGM, at least get a deep cycle. If you get the AGM battery then get an AGM charger too. I probably would not bother with getting an AGM for the starting battery, but that is just my opinion.

(Disclaimer: I do work for a company that manufactures AGM batteries and others as well, but I don't think that has had any effect of my opinion. Because I work for them I got an incredible price on my AGM, and I would probably not have went for an AGM if I had to pay retail, but I am cheap. Having bought one the only negative that I see so far is the weight.)

TerryMSU
 

Campylobacter

Chief Petty Officer
Joined
Aug 4, 2007
Messages
503
Re: deep cycle battery?

I disagree strongly with Richard above. even for a smaller boat, two batteries are preferred if you have a trolling motor, and especially if you have anything else (Radio, extra lighting, fish-finder).

I don't really think you disagree. What he said was:

you didnt mention the vessle type and size but on anything under 18-20' a single battery is standard. Of course it never hurts to be beyond standard.

A single battery is standard on those sizes. Of course standard is not preferred, and thats what he implied by saying it never hurts to be beyond standard. If he is running a trolling motor, of course the deep cycle is preferred, I think everyone agrees on this point.
:)
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: deep cycle battery?

The standard for bass boats is not a single battery though. The standard is a starting battery for the engine, and a deep cycle for the other components to run off of while the engine is stopped. Most bass boats incorporate two deep cycles to increase play-time. Most runabouts only have a single starting battery because they don't have any components that can run the battery down when the engine is off, aside from anchor lights and perhaps a stereo.

If my boat had a powered amp for the stereo, you bet your butt I'd have a deep cycle wired in to handle that thing sucking away the battery reserve.
 

Fl_Richard

Lieutenant
Joined
Jan 21, 2005
Messages
1,428
Re: deep cycle battery?

Did someone say this was a bass boat?

I thought I covered it well with:

"Now if youve got an electric troller, crank the tunes or fish for 9 hours with a 2kw sonar transducer and the motor off all bets are off."

Cheers All!
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: deep cycle battery?

for that 17ft 87 bass tracker with an 80hp motor. WHat kind should I buy (specs)
Am I going to need a seperate battery for the trolling motor/trim.

Thanks

Copied from a thread he started shortly after this one.
 

leer94

Seaman Apprentice
Joined
Jan 10, 2010
Messages
39
Re: deep cycle battery?

IMO...use two batteries. One for starting and one for the trolling motor and electronics.
For all of the reasons cited above...as well as, sometimes using the same battery for a starting battery and for things like fish finders can cause "noise" on the fish/depth finder.

...and in a fishing boat with a trolling motor...give yourself the safety factor of having two separate batteries. You do not want to go out and kill you only battery trolling around and then not be able to start the big motor to return to dock.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: deep cycle battery?

Also, in an emergency, you can always use the deep cycle battery to start the engine if the starting battery craps out.
 

Aqualift

Petty Officer 2nd Class
Joined
May 20, 2009
Messages
145
Re: deep cycle battery?

I have a 14' runabout with a 50 HP merc and a Motorguide Varimax trolling motor(also fish finder). I only use one battery. It's an EverStart MarineMaxx group 29. It has plenty of power for cranking and trolling all day. Never had an issue. When I get home, I hook it back up to the charger.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,778
Re: deep cycle battery?

They make combination batteries and WW and Autozone that I know of stock them....have bought from both places. I guess the combinations have thicker plates than normal cranking batteries, but not as thick as deep cycle which apparently are required to tolerate the deep cycling and survive.

I like having the cranking battery separate as it can be recharged in flight and if you run your trolling, music, household, or whatever battery(ies) down (BTDT) you still have a cranker to get home.....ever try to start an 85 hp with a separate crank rope, not auto rewind mind you, a separate rope? It's tricky but it can be done. Ha!

On the ability of a deep cycle to start an 80 hp outboard, I bought a 40 year old, 6 cylinder JD DIESEL farm tractor (95 hp) which had installed one 12v deep cycle (not the combination type, full deep cycle) marine battery that had apparently been used for a very long time. I was amazed that this deep cycle battery, being advertised as a low amperage type of energy supplier (hence unsuitable for pumping out the 200 amperes this tractor needed to start so they say), was in fact able to start the tractor efficiently and could do so in cold weather too.

Mark
 

H20Rat

Vice Admiral
Joined
Mar 8, 2009
Messages
5,204
Re: deep cycle battery?

Even with a big stereo an amp on a bowrider, I don't have two batteries... Why? First of all, i haven't ever run it down that far, I have an LCD voltmeter in the dash to monitor charge. Second, I ALWAYS carry a decent size jump pack. So yeah technically I have two batteries, but it is alot easier and lighter to carry a portable jump pack around than an entirely separate battery system.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: deep cycle battery?

Even with a big stereo an amp on a bowrider, I don't have two batteries... Why? First of all, i haven't ever run it down that far, I have an LCD voltmeter in the dash to monitor charge. Second, I ALWAYS carry a decent size jump pack. So yeah technically I have two batteries, but it is alot easier and lighter to carry a portable jump pack around than an entirely separate battery system.

That doesn't make any sense. It's not easier than having a second battery wired in with a battery switch. You still have to worry having the booster pack charged and in the boat.
 

rjlipscomb

Chief Petty Officer
Joined
Jun 2, 2009
Messages
582
Re: deep cycle battery?

I have a deep cycle battery in the boat and carry the jump start pack when boating. Having twin batteries is on my list of things to get, just not yet. The battery pack stays charged in the garage when not on the boat. It's good for jump starting the cars as well or when the boat has sat for an extended period of time. I think of it as my security back-up, not 2nd battery. When I get my twin battery set-up, the battery pack will still come with me boating.
 
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