To go to two batteries or not...

[SantaCruzin]

I'm a worry-wort...at least as it pertains to boating. I don't know what it is...with most things in life: work, play, cars, motorcycles, and family life I am pretty even-keeled, but when it comes to boating I am often a bit anxious. ESPECIALLY now that I have two small kids aboard our new-to-me '89 180 Bow Rider.

With that as background, I am a bit nervous about posting up in a cove with the family for an hour with the radio on and then going to head back to the marina with a dead battery. Our radio consists of 4 small speakers and a head unit so I recognize that I might be overthinking this, but I would appreciate any thoughts on if it makes sense to set up a second battery. I had a dual battery setup on my Pro-Line walkaround but I was out at sea and fishing for hours on end.

If I should consider it, would a simple 1/2/1+2/off switch do the trick or would you recommend one of the systems which can automatically manage boat batteries? I'm not eager to throw money at the boat for non-necessities but I'd rather be safe than sorry.

 

[sbw1]

I would I install a simple 1, 2, both, off battery switch. Good insurance and not very expensive.

 

[spikedaddy99]

You could also keep a battery jumper on board. I also installed a 12V gauge at the helm to know exactly where my system is and not run down the batteries.

 

[ygbsm]

I really like having two batteries, for peace of mind but also for the ability to extend the use of electrical powered devices- not only the radio and interior lights but electric air pumps for water toys. Simple battery switch should suffice.

 

[BillK2632]

I have two batteries in my 185 and have a simple off/both/1/2 switch. I typically alternate batteries each time I use the boat vs using one as starting the other as house. I have a stereo with amplifier and play it for hours at anchor, charge phones etc and never have a problem with it running a good battery down. I have had a battery start going bad from age and without the 2nd battery would have been stuck. I personally think two batteries are a good idea, even in a small boat. Just keep it simple with the manual switch.

 

[Stingrayaxe]

I have the same anxieties as you do. I needed to be towed in because of a dead battery in my first boat and never wanted it to happen again. I went the two battery route a few years ago on my then new to me 205. For the switch I went with the Blue Seas ACR. I never have to think about it. Either on or off. In the case of an emergency both batteries can be combined. More expensive but very convenient. I still worry but not to the same degree. I'm really glad I did it and consider it to be one of my top three upgrades.

 

[Leardriver]

The question is never whether to have two batteries. The answer is always yes. You are on water with your family, and a battery can fail, cable break, etc. The question is whether to have three.

 

[SantaCruzin]

Thanks everyone! Seemed like a no-brainer to me as well but when I was at West Marine yesterday the person helping me said "I think you're overthinking this, if you only have a small radio it's not needed."

 

[yobub]

FWIW, I've never killed a battery out on the water, but with kids on board something gets left on, and you don't find out until the next time you launch. I have had 2 batteries.on my runabout for 20 years, and just installed a switch. We'll see how it works this year. I also carried a jump box but with the old ones you had to keep them charged as well. The new lithium packs seem to hold their charge better.

 

[carterchapman]

I'm with yobub on the lithium ion jump packs - perfect backup solution. We have one in each car. Won't do much on our boat, but we run the genny 100%....

 

[Wylie_Tunes]

If I should consider it, would a simple 1/2/1+2/off switch do the trick or would you recommend one of the systems which can automatically manage boat batteries?

Im a huge fan of dual banks. I installed one on my 1st, 2nd and 4th boats. 3rd was new off showroom floor and had dual banks, but added a 2nd battery to the house bank for more Ah anyway.

I like the simplicity of a 1/2/BOTH switch, but an the captain, you need to make sure to have the switch positioned on 1 or 2 when anchored.

For those that want a dedicated house and dedicated main cranking banks, and not want to worry about the switch position, the dual bank switch and ACR are great.

 

[Arminius]

http://www.clubsearay.com/index.php?threads/low-voltage-disconnect.96463/#post-1108176

 

[BillK2632]

Another thing - if you put in a another battery/switch, make sure things like your stereo are wired to the switch and not directly to a battery. This way the switch position determines which battery is taking the load. The exception is your bilge pumps - they should remain directly wired to one of the batteries so they always have power.

 

[blaster]

Another option is a batteryless super capacitor. Lightweight and easy to carry on a small boat with limited space.

The device uses energy from the dead battery to charge the capacitors which then store enough power to start the engine.

better than a jumper pack in many ways from a reliability standpoint.
https://www.google.com/shopping/pro...1PMZEPPi_-quyfv3ygE,num:4,cs:1&tbs=vw:l,ss:44

 

[Arminius]

Very unlikely this would work. Power "from dead battery" is another perpetual motion device. Caps don't hold their charges. Caps work at higher voltages only obtainable from 12 v. with complicated inversion-transformer-rectifier circuits in and out, and Musk's ultrabattery factory in Reno would be obsolete. You don't leave your common sense on the courthouse steps (or when entering
Goggle.com).
I referenced my rig above and here is the picture. An 18' boat sure doesn't need another 60# battery in the stern:

 

[Henry Boyd]

I’m a big fan of the booster pack. But adding a second battery with a one, two, both, off switch is the way to go. One thing to remember is that when driving the boat, keep the switch on “both” to insure both batteries charge. Then come up with a system for determining which battery to use and then stick with it. With the 280 we used even dates for two and odd numbered dates for one.

The other thing with adding a new second battery is that if you can do it, buy two of the same battery. Identical batteries will have the same charging profile and give you the best results long term. If the current battery is too new to replace, maybe buy a booster pack to use for a season or two and then add two new batteries and switch.

 

[SloBurn]

Go with the switch. I actually have 3 batteries, 2 are house batts. I alternate battery switch every weekend, so they stay charged. Cheap insurance.

 

[blaster]

Very unlikely this would work. Power "from dead battery" is another perpetual motion device. Caps don't hold their charges. Caps work at higher voltages only obtainable from 12 v. with complicated inversion-transformer-rectifier circuits in and out, and Musk's ultrabattery factory in Reno would be obsolete. You don't leave your common sense on the courthouse steps (or when entering
Goggle.com).
I referenced my rig above and here is the picture. An 18' boat sure doesn't need another 60# battery in the stern:

I didn’t think it would work either but it does as long as the battery has some charge. I used one to start my f150 when the radio shorted out and turned on by its self.

I hooked my neighbors super capacitor up for about two minutes and the truck started right up. I don’t know how dead the battery must be before it no longer works but I’m sure the battery in my truck was very dead.

a lithium battery jumper as mentioned is another lightweight option if you keep it charged for when you need it.

if you go dual batteries I would recommend the blue sea add a battery kit. This comes with a switch and automatic charge relay ACR which relieves you of switching the batteries to charge. Instead, the starting battery charges up then the ACR switches to charging the house battery. Makes things very easy.

 

[Arminius]

The picture I posted above is of an installed Blue Seas low voltage cut-off switch on a one battery system. My boat came with a 1000 watt audio amp wired with #6 jumper cable style wires. We feared we would deplete the battery listening to Rush so I installed this switch on the cable to the amp. Cut-off voltage is variable but I left it at the default of 12.1 volts. There is also a buzzer that goes off when that voltage is reached in the system for any reason, like an anchor light on the non-switched circuit. The button overrides the cut-off or silences the alarm. I have put a 2nd battery in a couple boats before and they are an unneeded expense, weight, and maintenance headache. I have run custom cables up to a battery location under the front passenger seat to help with weight distribution. You will need to set your battery selector switch to "none" and use separate trickle/keeper/solar panels on them as you can't do both at once. Give it a rest, you've got a cellphone. Worry about UFOs or preposterous Global Warming.

 

[Hillzy_Aus]

I second the blue seas ACR system if you don’t mind spending the extra over a simple 1-2-both-off switch. No needing to worry about which battery you are running, hands down they are awesome.

here is my setup in my 175 which has a decent stereo (2 amps/sub + 6 speakers), iv got a dedicated house circuit run up front for the amps/gps&fishfonder/12v outlets and anchor/nav lights. Don’t even notice the weight and run 2x 75ah dual purpose marine batteries