View Full Version : 2nd battery vs. jump starter

Jeff d
03-25-2012, 11:13 AM
I occasionally run the radio at less than 50% volume while sitting with a single dual purpose marine battery. This has never exceeded 1.5 hrs or so and I've never had a problem cranking the boat up after. I'm still paranoid the whole time though.

This off season I added a class D 900 watt RMS amp so I'm even more paranoid about it now.

My initial thought was to add a deep cycle battery and an isolator. That's a bit expensive though with the additional wiring needed and what not plus the recurring costs of replacing another battery every 3-4 years or so.

I then started thinking that it would be overkill since I wouldn't ever have a need to run it off battery for more than an hour or so. I'm wondering if a jump starter would be a more practical and versatile solution. The intent would be never to run it long enough to deplete the main battery but I'd have the supplemental power if necessary.

Any thoughts on both options? This is on a wakeboard boat so weight isn't an issue.

03-25-2012, 11:44 AM
I had a single battery on my old boat running 4 amps. I did not want to add a second for the same reasons as you, so I carried a jumper pack and never needed it. It is more universal and easier to hand off to a fellow boater if needed....

03-25-2012, 12:00 PM
Go with a 2nd battery. And a perko style switch.

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Jeff d
03-25-2012, 01:13 PM
I'm not really interested in having a switch that I'd have to manually control when the isolator could do it automagically for about the same price.

03-25-2012, 01:43 PM
2nd battery and a jump pack for you and friends and long jump cables. you can never be overly prepared
BTW you might want to check the jump pack every once in a while, they don't hold optimum power forever

03-25-2012, 02:06 PM
I installed 2nd battery and isolator.

$200 all in and piece of mind on water with family. Priceless.

Battery = $85
Isolator = $75
Pos and Neg cable = $40

03-25-2012, 10:23 PM
I like having the second battery in our X-15. MC does have something in the system (on our boat) where it will automatically sound an alarm if the voltage drops below a safe level so you still have enough power to start. I have had this happen once when running the stereo for several hours while cleaning the boat. I have a jump box and on several occasions it hasn't had enough power to jump a car - even right after coming off the charger, I'll take two deep cycle batteries please - just my :twocents:.

03-26-2012, 01:39 PM
I prefer the setup of a Voltage Sensitive Relay to isolate the batteries and a switch. You need the switch to be able to manually override and combine the two batteries in case the starter battery goes south on you and you want to use the house battery to start.