2nd battery

Personally I think you are better off with a truck cranking battery than a deep cycle. I've never had a deep cycle last anywhere near the length of time a cranking battery has and gave up using them years ago.

I agree with Peter. I get a better run out of cranking batteries. Wet cell deep cycle batteries are hard to keep fully charged and die an early death. Thats why they only come with a 6/12 warranty.

Sorry guys,

That does not compare favourably with technical specifications as to the difference between a starting battery (lots of big amps for a very short period of time) versus a deep cycle battery, (small amount of current draw over an extended period of time.

The truck battery may work OK, but not as good as a good quality deep cycle battery if you intend running a fridge, etc.

Winsun

Yep, another vote here for the heavy duty cranking battery for 99% of the types of use/recharging most of us are likely to require.

I know there are a couple of exceptions, but generally speaking, deep cycle batteries were designed for use in things like "go-fors" (as used by aged and infirm folks) and golf carts etc. The demand on power is somewhat similar to what most of us require....IE: relatively low, but constant current draw (as required by a 12 volt compressor type fridge). However, it's what happens to top the battery up that is vastly different. A typical go-for user will ride around happily all day on their trusty machine, go home at night and plug it in to a dedicated battery charger which will trickle charge the battery slowly but surely, so that by the morning it is fully charged and ready to go again.

Compare that to the way we tend to do things..... we operate our accessories (most of which are low-draw items), sometimes for several days without re-charging. The battery gets low (ie: under 12 volts....some people reckon it's okay to let 'em get down to 10.5 volts!!! YUK, NO WAY) and then they decide to give the battery a kick in the guts to bring it back up to top volts by hitting the starter key on the trusty 4by. They may drive the vehicle all day, believing that the alternator will give the battery it's optimum charge level by the time they pull up to camp again. WRONG!!! Sure, the battery will be partially recharged and may even show on the multi-meter as being fully charged. Great! The issue is that the deep cycle has much thicker plates which don't cope well with the massive current/voltage inputs supplied by the alternator. The plates will start to break down in a "relatively" short period of time and you'll be up for a new battery.

I guess the one thing you could do to solve the problem if you were hell-bent on have a deep cycle battery would be to keep it TOTALLY isolated from the starter battery (ie: no fancy switching set-ups etc) and run an on-board 3 stage battery charger off 240 volts provided by an inverter which draws it's power from the main battery. I personally wouldn't do it that way, although I do have a 3 stage charger in both my truck and my camper trailer for charging the batteries off gennie or mains power.

Hi Sayo
I also doubt the value of deep cycle, but you want to check out the cost of each you don't want to be ripped off.

Rgds
Ian

Here is yet another vote for a truck cranking battery as the 2nd battery in a vehicle.

I used to run a deep cycle in the vehicle but they just didn't last. But I do run a deep cycle in the camper, but thats for different reasons (see Roachies reply above - sums it up perfectly).

I reckon the dealer has done the right thing by you for the wrong reasons!!!

Cheers

Captain