Deep Cycle Battery Advice

[shansta]

Hello,

Recently purchased a 4.9 boat and want to add a new deep cycle battery for my lights etc.

I am hoping some could give me some advice on what size ah battery I should purchase.

This is what I plan on running.

1) 2 metres of LED 5050 lighting. Which I think is roughly 14 watts per metre.
2) Fish Finder
3) Radio/Stereo
4) Power Inverter for laptop charging (max 1hr per trip)
5) USB for charging phones/Ipad (max 30 mins per trip)
6) Other LED cabin light, Anchor light etc.

I am plan to have enough power for upto 6hrs per trip.

I have looked on battery websites and was thinking about 100ah, but I am hoping there might be a pro who can tell me if I might need more or less.

Cheers

[Schulzy]

no expert but i would be looking at bigger might be better just incase if you arent running 2 batteries. if u have 2 then your laughing. i use century marine pro 720 good all round battery

[shansta]

Hi, I do have one just soley for starting which also a century battery. But I would like to run lights etc on a deep cycle.

[TheRealAndy]

100ah is heaps. Add a VSR so you second battery is charged whilst underway and you are laughing.

[Rip it up]

100AH is huge. It would run a waeco fridge for 12hrs.

I have a 14ft cruise craft. With 4st 60hp Yamaha. (Not sure of alternator output). I have a twin battery setup. Two 10" century marine batteries. 720cca I believe. Running through a 4 position master switch. OFF, BATT 1, BOTH, BATT 2. This can be switched under load.

Batt 1 is starter. Batt 2 aux. so I start off batt 1 at the ramp. Then switch to BOTH for the trip. This charges both batteries whilst running. All electrics are connected after the switch to a distribution block so power really comes from either battery depend on main switch location.

Items I have are. All lights old school bulbs.
Nav lights
Spotlight handheld 120W
Anchor light
Cockpit lights
Lowrance elite 5 chart
VHF radio

Never once had an issue draining batteries. If I sit at one spot fishing for a long time and I remember I will swap to batt 2 only just to make sure but it will start of that batt also.

I know that a redarc SBI dual battery setup would work really well if it was wired up the same as my 4WD. Using a cranking battery for main and a deep cycle for aux. all accessories would be wired of the aux. leaving the cranking just for the motor. Cranker to be first battery to charge and when at 12.7v redarc would switch charge to AUX. This would be my preferred option when I get around to re wiring the boat in the next rebuild.

I hope I shed some light on it for you.

[tunaticer]

Mate, your current requirements listed there are very minimal.
I run a 55lb auotpilot bow mount lecky for about 15 hours nonstop against the current on one deep cycle 100ah battery.
For the minimal abounts of draw you are entertaining I would probably opt for a 2nd cranking battery that is cheaper than a DC batt and can safely be switched to for cranking. If you were running incandesant bulbs all night for overnighters I would opt for the DC though.

[shansta]

Hey, thanks for the advice guys. Really appreciate it.

I am still thinking a deep cycle battery rather than another cranking battery.

Can you guys suggest a ah size that could handle at least 6hrs? Maybe 80AH?

I am planning on a isolator switch, a fuse box with some things hard-wired (stereo, fish finder etc.) and lights etc going to a breaker switch panel. Oh and now a VSR.

Cheers

[SnapHead101]

You need to look at the current draw of your devices. I'm only guessing, but I think 50 amp hour would suffice. Depends a little on how much you run your engine, and the alternator ouput of your engine. Also be aware that not all batteries charge at the same rate. Most deep cycles sit around 25 amp per hour max. Lifeline make batteries that will take as much charge as you can give it. That way if your alternator is say putting out 40 amps, you will be able to charge fully in around an hour (for a 50 amp hour battery). A 100 amphour battery weighs 30 kg ....
So take into account weights too. I'm going through a similar process at the moment too

[Towie0]

I agree 100a/h is heaps & its always better to have more than enough but 2 cracking batteries or a link to join the 2 in an emergency is a very good idea if the need arises.
Before spending $400 plus on quality deep cycle try a $200 multi purpose battery & see how it goes honestly what you want out of it going via your OP is SFA in power consumption.
I would go with a cracking battery around 650 or more the price wont change alot even go 850cca & if worried hook up a cheap solar panel if it doesnt last..

[shansta]

OK. Well with the isolator switch I was not planning on using the cranking battery at all besides running the engine and nav lights. When stopped flicking over to "2" for the second battery, whatever type I end up using.

I'm not sure about the solar panel, I have thought about it but I'm not sure what help it would be at night. After a night out I'll probably charge the battery before use again.

[TheRealAndy]

What size outboard do you have? You wont need a solar panel unless you are out for days and days.

I still reckon 100ah is overkill, but if you can afford the weight then go for it. Just keep it charged up when at home (along with your starter battery).

Oh, and what towie0 said, well as a youngen I used a standard car battery in my 3m tinnie. IT came out of my car, and went back in. That battery lasted me a good few years and lived through 3 different cars. The battery ended up going to a car dealer in a trade in.

[Towie0]

Actually thats a top idea pull the car batery out & use it as a trial or borrow one.
I have 2 motor batteries & 2 deep cycles for the leccy motror & i often throw one in the 4wd when e go away..

[Schulzy]

Hey mate the battery I suggested is a dual purpose I would go with a redarc switch handy bit of gear by the sounds of it you don't really need a proper deep cycle. The battery I quoted I use to run my 110 weaco. Deep cycles apparently don't like to be flattened ps eBay red arc $99 to your door

[WalrusLike]

If you have a dual purpose battery as suggested above, then you can use your primary to go out to your spot. That means its proven good and has had a recharge on the way.

Switch to the other battery and use it all you like. When coming home it will either have enough to crank and then get a bit of a recharge on the way home or it won't.... no worries, you got a proven good number one to switch to for the trip home.

[juggernaut]

Agree with the above comments in that you need a second battery capable of starting your o/b should the dedicated stary battery lose its legs.

Went through this process myself recently and went for a deep cycle lead acid battery in the form of a Trojan 27TMX. I would also go with 100 a/h battery as they are fairly common and compact enough to fit in most small boats with dual battery arrangements. And whilst is overkill provides piece of mind - but your call.

Add an ACR/VSR and both batteries will receive a charge based on the protocols of the particular ACR/VSR you select whithout the need for switching between batteries to maintain their respective charge. And in this regard the Blue Sea add a battery kit seems like a decent proposition with switch and ACR in the kit and available from Whitworths.

See attached link for a list of alternatives batteries:

http://www.everybattery.com.au/deep_cycle_batteries.php