I have a 2018 Serenity, owned it exactly 1 year and the house batteries were completely corroded. Had them replaced at the RV Service where we bought it. We went on a short trip less than 2 weeks later and noticed issues again with the batteries (not fully charging). We waited until the weekend to clean out the van and there is absolutely no power! The batteries are dead! Connected the shore power and the Magnum Remote shows a Comm fault. We are baffled. Does anyone have any ideas? We have had MULTIPLE issues with the Serenity since we purchased it December 2017 NEW. On another battery note: Has anyone changed out the rails on the battery tray? In order to do anything with the batteries, they have to be completely removed! The tray doesn't extend enough to even add distilled water to the middle and far cells.
I hear ya on those lead acid batteries. Went through the same thing on my Serenity (late 2016 model). After 8 months I went to check the water and Oh what a mess. My slide rails were corroded in-place. I soaked the rails with penetrating fluid, and banged and pried and never could get the slides to come out. The hold down strap ends had corroded off and it was just a mess of white powder. I was carefully able to work the connectors off (made diagram of how wires go since they use black for both + and -) and had to use small angled crow bar to lift and pull them over the battery tray edge to slide them out. These suckers are quite heavy for an old guy like me. I unbolted the battery tray and with a lot of pounding and penetrating fluid, I finally got them moving. The little bearings were caked in white powder. I spent a couple of hours cleaning up both rails and almost bought a new tray until I saw the price. After wire brushing the rails, wiping the bearings, greasing and getting everything back to almost new including cleaning up the batteries (water was not overfilled best I could tell). I got a new hold down strap and got everything back together and thought I would be good for another year. Then 6 months later I opened up the compartment and once again I had corrosion on the terminals, cables (but not the new hold down because it was now all plastic/fabric).
In early 2018, I just threw in the towel and bought a pair of Born Lithium batteries for $1850 shipped with a 10 year guarantee. After another thorough cleaning of the battery tray/compartment I installed the new batteries and never looked back. Everything inside the compartment is clean. No water to mess with, no back breaking job of removing the wet cells, no corrosion on the terminals, half the weight (I can actually lift these in and out). Because the new batteries are installed in parallel. One of the cables ended up a little tight, so I really can't pull the slide out much, I don't care. I don't think I will need to access these for several years.
The batteries have performed very well. My older Magnum 1212 charger does a fairly decent job of keeping them charged (have to un-power from shore power about once a month while storing rig). The un-powering for a few minutes is needed to get the charger to increase the voltage to 14.2, usually done just before going on a trip. That is the only issue and so minor, it's barely worth mentioning. Others have put in some expensive modifications to deal with that minor inconvenience. .
With the amount of money I have in this rig, the last thing I need to do is baby sit lead acid batteries every few months. In my younger years, yes, but that job was tough on my back and I don't need to be doing or paying someone when a good investment makes it un-necessary.
I too have had a share of annoying problems with my rig, but I hear that most of the time it is not unusual when there are so many components that make up this small house on wheels. Most of my worst problems have been with the Sprinter chassis.