2 batteries necessary?

mhensley

Cadet
Joined
Jan 29, 2010
Messages
16
We'll be new to the boating community after our Bowrider or Cuddy purchase in March. Is it wise to always have 2 batteries on a boat (one spare)? Or is this unnecessary. Thanks everyone! :)
 

skargo

Banned
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Sep 14, 2008
Messages
4,640
Re: 2 batteries necessary?

It is prudent to have 2, I know it makes me feel more comfortable knowing I won't be stuck with a dead battery.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: 2 batteries necessary?

There's no reason to have a second battery on board unless you run the stereo or other electrical equipment for long periods of time (more than an hour) without starting the engine. The dual battery setup is nice, but not essential, especially if you are only boating on small/medium size inland lakes.
 

scutly

Petty Officer 1st Class
Joined
Aug 20, 2009
Messages
368
Re: 2 batteries necessary?

We'll be new to the boating community after our Bowrider or Cuddy purchase in March. Is it wise to always have 2 batteries on a boat (one spare)? Or is this unnecessary. Thanks everyone! :)

the second battery is not really a spare. the usual setup is #1 (main) battery is a high amp cranking battery exclusively used for starting the engine. #2 (house) battery is a deep cycle type made for running electronics for extended periods of time. radios lights blenders trolling motors and what not. usually there is a switch that you must remember to turn when you want to start or sit and hang. you can also combine batteries in a pinch to start if needed. there are newer automatic switches also. the deep cycle battery is designed to be discharged and recharged many times in its lifespan, where that's not so good for the life cranking battery. there are also "combo" batteries that say it does both, but i have no experience with them and have heard on this forum that there not that great.
 

skargo

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Sep 14, 2008
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4,640
Re: 2 batteries necessary?

There's no reason to have a second battery on board unless you run the stereo or other electrical equipment for long periods of time (more than an hour) without starting the engine. The dual battery setup is nice, but not essential, especially if you are only boating on small/medium size inland lakes.

Exactly why I have a 2nd battery. We anchor, for hours at times and leave the VHF radio, and sometimes the stereo on. I start on #1, and use #2 for anchoring. I start back up on #1, then for the run home set the switch on both for recharging.

Like I said, piece of mind is worth something!
 

Utahboatnut

Senior Chief Petty Officer
Joined
Jan 15, 2009
Messages
785
Re: 2 batteries necessary?

I went many years with a single set up, but now that I have installed the double I wouldn't have it any other way. I had to pull start a 235 horse outboard once and it was BRUTAL, no one else out on the lake so it was paddle back or get it pull started. An I/O however pull start is not an option so, if this is your first experience with boats depending on what you get I would want at least a jump box. You may get it flooded and run the one battery thats in it down then you are stuck. Not saying you would but boats are a bit different than a car, and if its totally new to you thats when problems can come up. Know your starting procedure well and at a minimum have a set of cables with you.
 

smokeonthewater

Fleet Admiral
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Dec 3, 2009
Messages
9,838
Re: 2 batteries necessary?

unless you can easily pull start your outboard motor you should have two batts if at all possible.... It's just good sense
Ever have a dead batt in your car? care to try it in the middle of a lake?
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: 2 batteries necessary?

Exactly why I have a 2nd battery. We anchor, for hours at times and leave the VHF radio, and sometimes the stereo on. I start on #1, and use #2 for anchoring. I start back up on #1, then for the run home set the switch on both for recharging.

Like I said, piece of mind is worth something!

Didn't say it wasn't prudent to have 2 batteries, it just isn't necessary. The only boats we ever owned with 2 batteries were bass boats so we could run the trolling motor. Our ski boat only has lights and an old radio that we don't usually run more than an hour with the engine off. We also normally only boat on the weekends on a big lake with plenty of other boaters and a dedicated Lake Patrol (GRDA). Like I said, it's not necessary, but always a good idea if you have the money/space to accomodate the second battery/switches.
 

TerryMSU

Senior Chief Petty Officer
Joined
Jul 31, 2007
Messages
743
Re: 2 batteries necessary?

Didn't say it wasn't prudent to have 2 batteries, it just isn't necessary. The only boats we ever owned with 2 batteries were bass boats so we could run the trolling motor. Our ski boat only has lights and an old radio that we don't usually run more than an hour with the engine off. We also normally only boat on the weekends on a big lake with plenty of other boaters and a dedicated Lake Patrol (GRDA). Like I said, it's not necessary, but always a good idea if you have the money/space to accomodate the second battery/switches.

It really depends on how you use your boat. For example, I used to have an old pontoon that I only used for fishing. No trolling motor, no fish finder, and no radio. No reason whatever for a second battery. Plus the motor was a small motor that I could have pull started.

My current boat has a trolling motor, radio, and fish-finder. Plus I do not have the muscle strength to pull start it. (I found out the hard way.) Thus two batteries.

Your ski boat is a prime example of a case where the second battery is largely a waste of money and weight.

TerryMSU
 

Philster

Captain
Joined
Sep 15, 2009
Messages
3,344
Re: 2 batteries necessary?

It isn't necessary. That is hard to argue.

It is prudent. That is hard to argue, too.
 

stylesabu

Master Chief Petty Officer
Joined
Aug 2, 2009
Messages
849
Re: 2 batteries necessary?

It all depends on how you use your boat, your engine(in/outboard} if its fuel injected never going to pull start it.i would as previously mentioned get a decent jumper pack, under 100.00. And always have it with you. if main/single goes dead before your half way though your day of boating,then you will know that you need another battery. i fish in the middle of nowhere, so I have to be prepared for the worst. so i carry 3 batteries and a jumper box. as the only electricity is a gennerator. and if it don't start I'm screwed. So I'm prepared for the worst. just my 2 cents
 

smokeonthewater

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Re: 2 batteries necessary?

btw.... I have 4 group 31's (most cars are group 24 and most big marine are group 27) on my boat and might add one more
 

Silvertip

Supreme Mariner
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Sep 22, 2003
Messages
28,771
Re: 2 batteries necessary?

The answer to your question involves your purchase: 1) Bowrider or 2) Cuddy? If you have a bow rider that says buzzing around, skiiing, towing water toys etc. Cuddy says perhaps periodic overnights on board. The two boats require totally different approaches. A bow rider does not need a second battery unless you are inclined to add a gazillion watt stereo or other high current draw accessories. If you don't have any of that stuff but are still wondering about the possibility of a dead battery, carry a jump start unit. Problem solved. To add to that, know the proper starting procedure and keep the engine tuned so you don't have to kill a battery trying to get it started. If you end up with a cuddy, you will have late night lighting and other stuff to power so a large deep cycle battery is certainly suggested. Use a battery switch or ACR (auto charge relay) to isolate the two batteries while allowing both to charge when running. If you are unfamiliar with battery switches or electrically challenged, then an ACR is probably best for you.
 

RollingWanderer

Petty Officer 2nd Class
Joined
Jun 13, 2008
Messages
116
Re: 2 batteries necessary?

Where do you boat?

Personally...On any boat with a motor that I can't easily pull start, I carry a second battery wired in with a switch. Paddling a 20'+ glass boat any distance S^CKS!!! Ask me how I know...:rolleyes:

-RW
 

itsaboattime

Senior Chief Petty Officer
Joined
Jul 4, 2007
Messages
791
Re: 2 batteries necessary?

I carry two batteries, alway will. I have done too much paddling not to.
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,762
Re: 2 batteries necessary?

I have only one battery on my 20' bowrider I/O, thats how it came I have not added a second battery, although I did put a new battery in it last year and transfered the old (still viable) battery to my outboard boat. Both boats go on inland lakes, I don't like not being able to emergency pull start the I/O V-8. second battery or not.
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Re: 2 batteries necessary?

ya know they used to make a battery with a reserve built it..... if you ran it dead you flipped a switch on the battery and you could start ur engine...... I wonder if they still make em... of course they would prolly cost as much as a second batt but i dunno some folks might like em...

I have always brought extra dry clothes and shoes with me in a boat..... silly and not needed... useless.... except for that one chilly evening that I slipped and busted my hide on the swim platform and bounced into the drink.... when that happened I had just handed my battery over to another boater so he could start his boat. his alternator had gone bad and he only had one batt..... it wouldn't quite start the engine.....

He started up with mine and then swapped his back in and (after returning mine) headed for the dock. I changed clothes and continued fishing...

I got to thinking later that if that batt which at the time was my only one had gone in the lake we woulda both been stranded.
 

greggholmes

Petty Officer 3rd Class
Joined
Jun 11, 2008
Messages
95
Re: 2 batteries necessary?

I keep at least 3 on board

batteries.jpg
 
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