Hi guys,

What do you think about this device?

http://kollmanradio.com/pac200-battery-isolator-relay-p-5605.html

Any problems/solutions you want to share about dual battery system?

Thanks <img src="/forums/images/graemlins/cheers.gif" alt="" />

Personally, I have not found the need to provide for an isolator in my dual battery install.

I like to have a consistent draw on both batteries as I subscribe to the theory that consistent draw leads to longer battery life.

ON my motorhome, I do have battery isolators to disconnect the batteries so there is no parasitic draw when the MH sits for long periods of time.

The website you provided does have a quality isolator that is used in many applications and should work fine to split your two batteries.

The problem I see is that both batteries are treated as primaries in our dual battery system (unless yours didn't come with duals from the factory). As John said, they want consistent draw, and for that matter they should be identical in age and type, and should be replaced at the same time. If I was going to isolate two, I would swap the system to one (huge) battery for starting, and then rewire for an auxiliary battery for your accessories.

Instead, I've chosen another route. I have left the factory system as is, and isolated a third battery (in the back) for accessories, such as inverters, camplights, etc. I also have a momentary switch so I can parallel the three if I've run the two mains down (two yellow top hybrids, so unlikely).

Used this setup: http://www.ase-supply.com/Sure_Power_1314_Battery_Separator_p/sp-1314.htm

Phil's solution adds a new dimension to the discussion.

To take that to a new level of discussion, I would offer there are some factors that need to be established.

Basically, do you want the extra battery to provide added capacity when using a winch or axillary lights?

Or, do you desire the extra battery to provide added capacity to run accessories while keeping a primary starting battery alive?

This provides two different install options.

In the case of needing the extra battery to provide added capacity when using a winch or axillary lights, a straight dual battery install with no isolation would be optimal.

In the case of needing the the extra battery to provide added capacity to run accessories while keeping a primary starting battery alive, an isolator or even a secondary system with one or two batteries would be optimal.

In the second case, a battery isolator two keep a primary starting circuit alive would be a good investment.

That comes down to what is your intended use? Carefully consider your intended needs and base your mods from there...

If the option is for #2, care needs to be given to the type of battery used to run accessories.

Basically, starting batteries need a specified Cold Cranking Amps as a base factor.

If you want a long duration current draw, you need to consider the reserve capacity factor of a battery. I don't have the details handy but Optimima has info available about this.

So, if providing power for campsite accessories is important, you need a battery with a "deep-cycle" capacity that will provide current draw capacity over time with a quick recovery cycle.

Such a battery does not make for a good starting battery.

Thanks a lot for info, guys! <img src="/forums/images/graemlins/cheers.gif" alt="" />