Generator start from deepcycle batts OR dualpurpose batts?

Our rear engine DP generator starts with the house batteries which are 2 6volt deep cycle batteries. Never had a problem with this setup.

The reason I ask is because we have two Group 27 12v Marine Dual Purpose batteries that start the generator and provide house 12v. Wondering if I can switch them out to four 6v Deep Cycle batteries for more amp hours, and still be able to start generator.
My concern is that 6v Deep Cycle batteries do not have as much cranking amps for my 8kw diesel generator.

I do have two Group 31 batteries for the chassis and four seperate 6v deep cycle batteries and inverter for the all electric fridge already.

JimM68 wrote:
To my knowledge most all coaches wire the genny start to the house batteries.

Exception would be some really cool rigs like Bluebird wanderlodges, their gennies actually have their own battery!

Not true at all. There is NO real reason. ALL OEM's make their own decision on which battery bank to use. The "general" rule is, a Rear Engine diesel with the APU up front will use the Chassis batteries to start the APU. The do that because they already have to run a heavy large battery cable up front from the chassis batteries(most are in the rear) and they do not want to run a extra dedicated battery cable just to start the APU. Also, GAS motorhomes usually do have the Coach batteries start the APU since the coach batteries are closer to the APU than the chassis battery that is up front. Doug

KD4UPL wrote:
Mine's a dual purpose because only a group 24 will fit in the compartment so there aren't any deep cycle options.
If one would fit, I would use a deep cycle battery. Any deep cycle will start a generator just fine. The little motors don't take that much current to turn them over.

Group 24 ARE deep cycle. We install Interstate Group 24 deep cycles in ALL our Towables. Doug

The answer is yes, either will start the genny. Ours has a dedicated generator battery.

To my knowledge most all coaches wire the genny start to the house batteries.

Exception would be some really cool rigs like Bluebird wanderlodges, their gennies actually have their own battery!

My generator starts off the house batteries.

Like others said,it doesn't take much battery to start a generator and a duel purpose battery is fine, true deep cycle batteries will normally last a lot longer .

Mine's a dual purpose because only a group 24 will fit in the compartment so there aren't any deep cycle options.
If one would fit, I would use a deep cycle battery. Any deep cycle will start a generator just fine. The little motors don't take that much current to turn them over.

Short answer yes.. The generator starts off the house batteries, the starting draw of the genny is fairly low.. in fact once when I accidently killed both house and chassis batteries and thus had nothing left to crank her up with I dug out one of the garden tractor batteries I used on my wife's scooter. these very small batteries are like less than 10% of the house batteries. And it fired right up and held till the transfer switch kicked in and the PD9180 began providing power..

So it really does not matter. to a pair of GC2's (230 amp hours) the starting demand of the generator.. Is less than what a golf car would need to move you to the next T.