LMM: Dual battery trickle charging

[ChuckE]

Hi Y'all, The FOG here,
I have an issue with my Chev, C-5500 Kodiak motor-home that at the moment stays in storage for long periods of time and the chassis batteries slowly fade away.
I would like to put a trickle charger on them. When the house portion is plugged into 110, the house batteries get charged and the chassis batteries don't get charged. Soooo, here is the issue; How do I connect a single 12V charger to the two motor-home chassis batteries without causing any problems to the electronics? I have had to have AAA come out to a campsite to jump start this rig, [when I left an auxiliary refrig. on accidentally all night], and they used a lug under the hood and a ground, but another time another jump had to use 24 volts on those lugs. At this writing, I am not able to determine if the batteries are wired in parallel or series since the rig is 90 miles from me. Does anyone have any definitive direction or approaches I should take to get that trickle charger to charge both batteries?
Thanks in advance for your thoughts.

 

[Bdsankey]

Hi Y'all, The FOG here,
I have an issue with my Chev, C-5500 Kodiak motor-home that at the moment stays in storage for long periods of time and the chassis batteries slowly fade away.
I would like to put a trickle charger on them. When the house portion is plugged into 110, the house batteries get charged and the chassis batteries don't get charged. Soooo, here is the issue; How do I connect a single 12V charger to the two motor-home chassis batteries without causing any problems to the electronics? I have had to have AAA come out to a campsite to jump start this rig, [when I left an auxiliary refrig. on accidentally all night], and they used a lug under the hood and a ground, but another time another jump had to use 24 volts on those lugs. At this writing, I am not able to determine if the batteries are wired in parallel or series since the rig is 90 miles from me. Does anyone have any definitive direction or approaches I should take to get that trickle charger to charge both batteries?
Thanks in advance for your thoughts.

Determine the voltages of each system. If the voltages of each system are the same, you could run a charging wire from the house batteries on a relay that is triggered by incoming 110v to allow current to flow to the starting batteries. Another option would be to ensure the circuits are separated and buy a trickle charger than takes 110v input and outputs the voltage of your starting batteries (I'm assuming 12v based on it being an LMM chassis but who knows) and hardwire that into the 110v side of the motorhome.