Good afternoon. Nick & Tonya DiMarino from Littleton, NC here. We appreciate this forum and allowing us to be a part of it. We are recently semi retired, purchased a pre-DEF motorhome of our dreams about a year ago. It is a Monaco Commander 45 Signature. Excellent condition inside and out with all the luxuries of home. Our toad is a 2013 Jeep Wrangler purchased as a package deal. It is our first DP, but we have been camping our whole lives from a Coleman pop up to our last onw which was a 38' gas Newmar Kountry Coach prior to this. We took our coach cross country nearly 15,000 miles last fall and have made numerous smaller trips since. Our Monaco is a dream Coach in near flawless condition and we are thrilled with it, but I do have a few kwirks to work out like any RV. I have been watching posts in this forum for a few months now and have really enjoyed reading experiences and hearing ideas. I have used many of the ideas to much success.
I have had what seems like "weak" chassis battery bank since I bought the MH. When I first turn the key it seems very weak and the engine barely turns over. If I continue to hold the key in the start position for just a few seconds it will usually begin to turn over, it gets faster / stronger and typically lights right off. I was getting an oil change & filter at Loves and had them replace the batteries even thought the old ones (2019 date code) load tested just fine. To my surprise it is exactly the same with new batteries. This weekend I had to jump start it, as the batteries were down to only 10.5 volts. I keep my motorhome plugged in and inside a garage while at home. I religiously water my house batteries and keep them clean. I keep corrosion off and use inhibitor on chassis and house batteries. From reading this forum I realized that my stock Magnum inverter didn't charge the chassis batteries, so I installed the maintainer which I keep plugged into the Engine heater receptacle and left turned on while the coach is not being used. It is stored inside a garage when not being used and is also fairly climate controlled (no extremes anyway). I cannot figure what is draining my chassis battery or why it would be weak when cranking at first. I am no self proclaimed "mechanic", but I am a do it yourselfer with a good deal of God given common sense. Could anyone offer me any ideas on what could be the cause of this? I feel like it is highly unlikely that its the starter because it only has 50,000 miles on the coach, BUT it was weak starting even with brand new batteries..... However if it were the starter itself then that doesn't explain why my chassis battery bank would tend to drop (drain) down even while connected to a maintainer. I do not see corrosion or any obvious problem when i visually inspect. I do not want to be a parts replacer. Your help and expertise is much appreciated! Incidentally I am not used to using forums, this is my first. I tried to check using the search features to ensure I am not asking a duplicate question / topic so if I am, it is not intentional.