Your multiple battery setup and reasoning behind it...

Erik · Last edited by Erik on Jan 30, 2006 6:16 pm; edited 1 time in total

People on here talk about their multiple battery setups and it dosent seem that we ever really talk about WHY folks have multiple batterys. I understand the need on something like a fishing boat or bass boat, but with regard to wake boats, I am having trouble seeing the need. I have an aftermarket stereo, I spend a lot of time floating around and listening to music with the boat off and have never experienced a problem with the ski nautique 2001 or the 210.

I guess I am just wondering why people do it in the first place. And as an add-on to that question, what are your setups? 2 cranking batteries? 1 Cranking and 1 deep cycle? How are they wired? Lets make this the batter info catch-all thread, so that I can understand why people do this to their boats, and try to decide if I need to do it myself.

Thanks,
Erik

brew · Posted: Jan 30, 2006 7:57 am Post subject:

If all you are doing is parking and listening to a fairly standard stereo setup, then a single battery setup is likely sufficient. However, lately a lot of the systems I see are starting rival what you find in a lot of cars. They are running multiple amps and subs, crossovers, and video equipment, while also running a host of neon accessories. With all of the extra equipment, most of which will drain a battery fairly quickly, I can see the need for multiple battery systems.

Cyclonecj · Soul Rider Joined: 12 Jan 2003 Posts: 338 City: Atlanta

I have one Optima cranking battery and one Optima blue top deep cell. They are separated by a Hellroaring isolator combiner. I have about 1200 watts rms, and a 90 amp alternator. I also have a six light bar and LED lights and stuff, PP, satellite radio, etc. SO, I added the extra battery and isolator to be able to not worry at all about being able to start my boat after staying out late and using the stereo all day, the lights, other accy's. With one battery, I could run it flat in a couple of hours of floating listening to the stereo.

I have also had conventional batteries fail while riding. Hitting double ups can break them apart inside, they short and fail. You don't know until you shut the boat off and try to restart it. I would have two batteries in any boat just for that reason.

SuprAir · Outlaw Joined: 10 Jul 2003 Posts: 180 City: Columbus

Obviously fishing boats with trolling motors need battery backup, but multi-battery setups in boats has long been common practice for safety considerations. Unlike a dead battery on a car, you can’t just walk to the nearest service station or phone when stranded in a boat. Also, a lot of recreational boaters have more a tendency to let their boats sit unused for extended periods of time, weakening batteries. Another reason it’s not a bad idea to have a backup on board.

For wakeboarders who use their rigs on a regular basis it’s not as big a deal, but if you sit and listen to tunes for hours on end (or have major draw for monster tunez) you probably should consider a battery just for stereo and one dedicated to starting.

That being said, I’ve gotten along with my small stereo and a single battery just fine. Only as of late am I considering some stereo upgrades and an additional battery.

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

i have a 2006 supra 24ssv and i have dual batteries with a switch (1-2-1&2) My boats is storage and i am pretty sure one cranking one deep cycle. I just got it for the security. I dont crank my music up too loud or leave my light bar on, but i would be pissed to be stuck out on the lake and have to get a tow. IT only costed like 150-200$ for the opt. 2nd battery

acurtis_ttu · Soul Rider Joined: 16 Aug 2004 Posts: 499 City: Houston

I took it one step further. I added two 6V golf cart batteries, and one starting battery. I use my golf cart batteries as my main battery (acc and starting) and use my starting battery as backup. I switched all boat power to the golf cart batteries and keep my perko switch on battery #2, at all times and use #1 as a backup only.

I had my alternator go out on me and was able to run all day on my golf cart batteries all day w/o any problems.

Commodore · Ladies Man Joined: 20 Jun 2005 Posts: 11636

I have two in my 90 Supra. Main reason is for safety and backup. The other is I run a decent stereo and plan on LED's throughout the boat. So again it's mainly for "just in case" scenarios.

NAW · Posted: Jan 30, 2006 9:39 am Post subject:

I ordered the dual battery option on the '06 as well. I figure it's cheap security, allows for systems upgrades and can add that 20-30lbs to balance out some weight.

Wakebrad · Ladies Man Joined: 11 Dec 2003 Posts: 12257 City: Dallas

cloud · Criminal Joined: 03 Nov 2005 Posts: 60 City: Austin

During the winter, I don't sit around with the tunes blaring, but this summer I'm just going to throw a jumpbox in the boat "just in case."

Something like this one, which will come in handy a lot more than a spare Optima in the back of my boat.

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

that looks like it is worth it for 60$

acurtis_ttu · Soul Rider Joined: 16 Aug 2004 Posts: 499 City: Houston

Draingin down your battery to the point wher they need to be jumped time and time again is nto good for hte battery and will decrease it's life (deep cycles will obviously last longer treated like this). On top of that when you run down yoru battery so low it needs to be jumped then start your boat...your putting a huge strain on your alt, especially if you try and turn back up the stereo, lights, ect.... be prepared to smoke it.

jason2454 · Outlaw Joined: 18 Feb 2005 Posts: 240 City: austin

i could probably use a 2nd battery in our boat... however for 40 or 50 bux you can buy a portable jumper if your worried about getting stranded. Ive jumped the boat 3x in one day and the charge meter on it still said full charge. Only reason i would get a 2nd battery is so my subs stop cutting out.. For some reason they cut out only when the boat is running. When the boat is off and the stereo is on they never cut out at high volumes. Kinda wierd..

Sbt3 · Soul Rider Joined: 27 Jan 2003 Posts: 279 City: Okauchee

I have 2 batteries in the boat mainly for a backup. I have had to use it a couple of times. I forgot to shut off the stereo in the boat one night and the next day the main battery was dead. Rather than having to mess with jumping it I just switched the perko switch and it fired right up off the 2nd battery. Just remember to keep it only on one battery otherwise it will obviously drain them both dead. Some other posts in the past on the forum have described using a relay to switch them which looks interesting I just haven't bothered to look into it further.
Erik- heres a pic of mine in my 97 supersport.

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

so u guys leave your switch on 1 or the other not both? i have always left mine on both?? Just wandering

acurtis_ttu · Soul Rider Joined: 16 Aug 2004 Posts: 499 City: Houston

Think abotu it for a second.......keeping the switch on both defeats the purpose of having two batteries. You cna run into other issues if your batteries are different types and ages.

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

im not sure if oneis Cranking and one Deep. I cant check because my boat is in storage. On my other boat (38 baja) i have three batteries on a switch but one starts on engine the other statrs another engine and the last one is a deep cycle (the first two were cold cranking) and it runs lights and stuff and also starts the jenny. I wander if it is setup like that. Like one starts the engine (cracking) and the other runs the stereo and stuff (deep cycle)

justsomeguy · Guest

I went with two batteries w/ a Perko switch because...it's standard on my boat.

chavez · RIP MHL 04/25/1958 - 01/11/2006

austin11, the switch should only be on "both" if you need both batteries' juice to start the boat.

Otherwise, the switch should always be on 1 or 2, but not "both".

When in "both" position, it forces the alternator to charge both batteries at once, which will severely shorten the life of that alternator.

This is why you should have a switch AND an isolator - to charge on the battery in need and still have the fully charged battery in reserve. You will still have the ability to use 1, 2, or both (in dire situations) to start the boat, but both batteries will charge safely and as necessary when the motor is running.

Here is a great diagram of how you should wire it up:

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

that was a lot of help thankschavez,

RoughRiverMike · Outlaw Joined: 08 Dec 2005 Posts: 107 City: louisville

So to keep both batteries in good shape and charged up should I switch from 1 to 2 on alternating days to charge them both up? Question

My 03 Malibu came with 2 and I kept it on BOTH all the time and never had a problem. I thought that I should do it that way to keep them both charged. I'm getting a new boat and I want to extend the life of both alt and batteries.

chavez · RIP MHL 04/25/1958 - 01/11/2006

RoughRiverMike, check your new boat - see if they put an isolator in stock. If not, I would really think about dropping the $80 or so bucks to get an isolator.

Do it right - you will get many, many years of service out of your alternator.

If you don't want to bother with the isolator, then I would recommend just keeping it on 1 while underway. Maybe invest $20 at Wal-Mart and get a low amp float trickle charger to attach to battery #2 to keep that baby topped off and ready for emergencies.

If you don't have this option (boat in storage, etc.) then you may want to look in to installing a solar panel (20-30$ at west marine) to trickle the battery. I installed an inexpensive cigarette lighter adapter near my battery, wired it directly to batt #2, then plugged in the solar panel and put it on top of my cover using some velcro. Boat always fired right up, even after months of sitting.

acurtis_ttu · Soul Rider Joined: 16 Aug 2004 Posts: 499 City: Houston

Great advice Chavez.

Wakebrad · Ladies Man Joined: 11 Dec 2003 Posts: 12257 City: Dallas

chavez, maybe you could explain this to me. How does it put any more strain on your alternator to charge an almost empty battery than charge 2 half empty batteries?

I'm not familiar with how alternators change output based on the need of the battery.

Stanfield · Outlaw Joined: 01 Dec 2004 Posts: 131 City: Dallas

I have the same question as RRMike.

Constantly hooking a trickle charger up to it is a PITA. Wouldn't alternating between battery 1 and 2 every other time out do the same thing and work well?

I'm not even sure which battery is 1 and which one is 2. Everything works either way I have the perko set to.

chavez · RIP MHL 04/25/1958 - 01/11/2006

Wakebrad, think of your alternator as an amplifier. When you put the speakers in parallel, you force the amp to work twice as hard to compensate. The amp heats up because it is now working twice as hard, and if it's not designed to handle that load, it will kill it/melt down in short order.

Same idea applies to the alternator. If your alternator is designed to handle it, ok. However, most alternators are single output only. There are multiple outlet alternators available, but why bother when you can yield the same end result from an isolator setup that will properly monitor and charge the batteries? This is why the most commonly used setup is the isolator + 4 position switch setup as diagrammed above.

acurtis_ttu · Soul Rider Joined: 16 Aug 2004 Posts: 499 City: Houston

Stanfield, you can leave "half" of the trickle charger hooked up to the battery and just plug it in at the end of the day...very easy.

chavez · RIP MHL 04/25/1958 - 01/11/2006

acurtis_ttu, exactly. They include the necessary cord and plug in the box.

Alternatively, you could do what I mentioned for the solar charger and apply it to the plug-in trickle charger. Just takes a few minutes to initially set up.

Tmac1 · Posted: Feb 01, 2006 12:59 pm Post subject:

considering the cost of boats today -- an extra battery set up can cost -- what... $150? After a couple times being towed in you may realize it's not about trying to find reason why not to have it -- it's simply becomes a nice security/ back up...

RoughRiverMike · Outlaw Joined: 08 Dec 2005 Posts: 107 City: louisville

Chavez, Thanks for the tip on the isolator. I don't really understand how they work, but I hope my MC dealer does. Im getting every option available on the boat so I shouldn't skimp on a $100 option.
Is it something that would be put on the boat at the factory or would the dealer do it?

polkaking27 · Outlaw Joined: 31 Jul 2004 Posts: 142 City: Vancouver

I'm a little shady on what the isolator does. If you install the setup above you have the isolator and switch. How does the isolator know which battery to charge, or does it. What is the point of both the isolator and switch. I'm sorry if this question has been answered before, Its really been buggin me and I can't find it anywhere.

THanks

chavez · RIP MHL 04/25/1958 - 01/11/2006

polkaking27, RoughRiverMike, the isolator monitors the charge in each battery and sends current where necessary, while isolating the battery to prevent overload on the alternator.

Think of it as a router, or even an "intelligent" splitter.

The point of having a switch AND an isolator, is to have either battery available for starting duties.

Also, Mike, if the dealer will do it and warranty it and not charge you an arm and a leg, I say go for it.

oshensurfer · Posted: Feb 01, 2006 5:37 pm Post subject:

Didn't read all of this, but it's insurance for me. I can't tell you how many times, I've been on the Delta or even on the lake and either been the last one on the lake or not seen anyone for hours.

srh00z · Outlaw Joined: 09 Nov 2003 Posts: 128 City: Birmingham

I have two for insurance also, I have jumped off several people on the water, so I don't want to be in their situation. I don't have both hooked up though, I just alternate and use one battery one week and the other one the next.

austin11 · Criminal Joined: 23 Jan 2006 Posts: 74

ok now that i kno all of this i will be using one battery one day and the next time i will use the other. I dont ever leave the batteries on a trickle charger except during the winter i leave a trickle on both. So if i do this alternating method. I wont need an isolater. Because the what ever battery i have the switch on the alternator will leave the other battery out of the charging beacuse its only set on one battery. Correct???? PLz correct me if i am wrong.