starting vs deep cycle battery

[searay215ec]

Hi Guys

I have 2 marine starting batteries in my boat connected with a make-before-break off-1-both-2 type switch. All electronics run off whichever battery is selected with the switch.
What i usually do is use position 1 to start and run, then when stopped i switch to battery 2 for radio etc. Then when heading back i start and run back on battery 2 and if we stop again i start and run battery 1 again.

I need to replace battery 2 cause it doesnt hold charge anymore and is about 4 years old.

My question is should i buy another heavy duty starting battery or a deep cycle battery?

I have read that some deep cycle batteries can start engine in case of emergency but it does shorten their life.

Since i always alternate between batteries when starting should i just stick with starting battery?

The batteries i have are from bias boating
http://www.biasboating.com.au/batteries.html
Cat. 2553X

Cheers

[ssab1]

stick to marine starting they are made for the work required,heavy discharge quick recharge.cheers

[Chimo]

Hi Searay215ec

You havn't got a shorter nick name have you?

Best to use starting batteries for starting and the deep cycle for electonics etc.

What is a more interesting question is
Have you got your electronics, ( I assume you have electronics) on a circuit separate from your starting circuit especially when you start your motor (s).

The issue is the voltage spikes generated by the motor (s) as you start them.

I initially was told by dealers don't worry about it and I didn't until I lost pixcels from the GPS screen. After the GPS was replaced on warranty the circuit was changed with an auto battery coupler added to separate the starting circuit from the electronics (and deep cycle battery) while the motors were started with auto reconection only after the voltage levels had settled down.

Happy boating

Cheers

Chimo

[impulse492f]

I found this great site that explains batteries, what type, charging etc and is interesting reading (if you like this sort of stuff)

http://www.rpc.com.au/products/batte...cle/carfaq.htm

Section 7 is all about what sort of battery does what.

[blaze]

IMO the only real reason for a deep cycle battery in a boat is for electric motors, fridges etc. I beleive all sea going boats should have 2 start batteries, run on 1 battery using it to run your basic electrics, sounder, gps, nav lights etc and leave battery 2 at 90% charge for its designed use, emergency start.
cheers
blaze

[boat_1]

Hi, I would stick with the standard type marine batteries, i also have a similer setup to you. When i bought the boat it had a Century marine 600 battery fitted as the main & a heavy duty car battery fitted as the secondary one. It wasn't too bad, but i nearly got stranded out near Mud Island after an overnighter, just managed to start it. I purchased a Supercharge Seamaster 650cca battery to replace the automotive type one, it is brilliant. I can run sounders, radio's lights etc for over twelve hours & still start the motor with only one battery. Just yesterday i bought a second one to replace the Century marine battery. I bought a M70 model, but there are heaps of different ones available. Cost was a suprise as well, around $150 retail, i got mine for $110 trade.

Just my opinion, others may beg to differ,
Andrew.

[searay215ec]

Hi Guys

Just replaced it with another marine starting battery Century marine Pro 600. Once i get a fridge i will be looking at the Odyssey batteries, they have come highly recommended.

Cheers

[Roughasguts]

A deeep cycle battery will or should take 12 -24 hours to charge at low Amps, and should only be used for low Amp discharge. Not for starter motors.
There also not much good at taking big Amps from your alternator for 5 or 10 minutes. Your better off for the long usefull life if you charge 2-3 Amps in them at home for a day or Two.

A cranking battery gives out big Amps for a short time, and will take big Amps for a charge, and recover fully in around 10 - 20 mins there really the only thing to have hooked up to your motor. They don't like slow discharge at all, you can't get away with it for more than a few hours, they don't have the storing capacity, around a 10% loss and there flat.

Leave the deep cycle seperate, charge it at home, it will take a 60-70 % loss easy and still not be flat.