View Full Version : Deep Cycle for Accessories??

Scott nthQld
10-09-2008, 10:27 AM
Hi all.

I currently run just the one battery with everything hooked up to it.

I want to get a second battery so I can use the main for exclusively cranking the engine, as I've found that running all the nav lights, sounder etc.

Instead of getting a conventional battery, i was thinking of getting a deep cycle to give me more battery life when on the water between charges.

Would a deep cycle be suitable for running a sounder, nav lights, radio, and soon to come a new GPS Plotter? Or would I be better off just using a second marine battery?

10-09-2008, 10:50 AM
A deep cycle will work, but is it worth the extra dollars? The big bonus about buying a second cranking battery is that you can use if for cranking! Keep a small shifter handy and that way if you ever need to swap the second battery in you can!

Keep it charged up and it will last just as long as a deep cycle. The gear you are running off it is hardly going to put a drain on the battery, unless you have it all switched on for a week without charging it.

10-09-2008, 10:56 AM
According to Exide, you can use a deep cycle battery for cranking if you size it accordingly, so a deep cycle might be the best choice. Some more info here http://www.exide.com.au/products/deep-cycle.php?info=1

10-09-2008, 11:21 AM
The other way of looking at it long term is.
to buy a new cramking battery and shift the old one over to accessories.
and continue the practice indefinitely... that way you always have a good crankng battery.

If the battery is a decent size 90AH all should be fine.

It is definitely worth replacing all your nav lights with LEDs or fitting LED globes.

typical all round white... 10 watts conventional...... replacement LED 2 watts.

do that right across your on board lighting and you reduce your load and increase your battery run time considerably.


10-09-2008, 11:23 AM
you can use any battery for cranking if its sized accordingly. But they deep cycle is a lot of dollars when you dont really need it.

10-09-2008, 12:59 PM
Hi Scott,

As others have said, the deep cycle will work well, but imo not worth the money. I use a 120a/h deep cycle to run a freezer for which it is perfect, but for all other electronics I have two sealed cranking batteries. These are set up via an isolator switch so I can isolate one at night. I run sounder, gps, anchor light, fluro deck lights, livie pump etc and have never had a problem.