Our 2015 Challenger coach came with 2 no-name (read cheap) 6V Flooded Lead Acid batteries. We replaced them with 4 Lifeline GPL-6CT AGM.
This significantly increased our ability to run off the batteries. Before we had around 5 hours just running the residential fridge and other minor draws. Now we can go for 24 hours with a full house load (fridge, lights, TV, Computers, phone recharging, etc.), basically everything except A/C and Microwave. Currently we recharge these AGM batteries from shore power, the generator or the engine alternator. In the future we plan to put in some solar panels.
As a word of caution, before you purchase new batteries, especially lead batteries that have to be positioned right side up, check your battery storage compartment to make sure that they will fit. We totally lucked out here and our new batteries just squeezed into the available vertical space.
Link is: GPL-6CT - Lifeline Batteries
Before we installed the shut-off (below) we once drained these batteries completely and thought we totally ruined them. But after 48 hours on the charger there came back to life. Pretty impressive.
We installed a Victron BMV-702 with a Blue Tooth dongle.
We love this thing. It monitors draw and recharge, has high/low voltage alarms, 30 day history of batteries and more. Whatís great is that with the Blue Tooth Adaptor we can read all this data from our cell phones.
Link is: https://www.victronenergy.com/battery-monitors/bmv-700
We are planning on doing a complete 1,000W solar install using Victron gear. Victron exudes typical Dutch pragmatism. World leading innovation and quality that is proven to work at a reasonable price.
Battery Auto Shutoff
We also installed a Victron Energy Smart Battery Protect 12/24-Volt 220 amp (Bluetooth). This device will disconnect the batteries if the voltage goes below a set value. Because it is Bluetooth enabled we can also manually shut-off the batteries.
The 2015 Challenger comes with a WFCO Convertor/Charger. If you are going to make the investment to buy top-notch batteries, then I highly recommend getting a top-of-the-line charger. Victron, again, preferred but if that is out of the budget go with a Progressive Dynamics PD9260CV Inteli-Power 9200 Series Converter/Charger with Charge Wizard - 60 Amp. This unit has all the bells and whistles to keep your expensive batteries in good condition.