Originally Posted by camaraderie
Easiest way to tell is with a clamp meter. Clamp it around the main red batt wire with the salesman switch turned off and you'll know exactly what your parasitic amp drain is. The you can pull fuses or clamp directly connected wires to see what the parasitic drains are. Alternatively...if you're not curious...just disconnect the negative wire when in storage (and after charging to 100%) and your batts should be good for 2-3 months minimum even to 50% charge.
You have over 400 amp hours of battery bank with the 4 6V's . A .5 amp parasitic draw would flatten them in 5 weeks even if in like new condition... but a .5 amp draw is way more than just a propane detector. If the clamp measurement doesn't show close to that kind of draw...I'd bet on murdered batteries and would NOT blame the dealer unless they were told to charge them and they actually froze and you can see case deformation or cracking. . BATTERIES that are charged don't freeze...discharged ones do. Abuse in charging /discharging regimens...cooking batteries by leaving on full time charging...and failure to keep the water up are the main ways batteries lose capacity and fail. But something like a Magnum on standby and not wired through the cutoff switch can kill a set quickly too.
If you don't have a clamp meter that can read DC amps...they are very handed to have and start at about 50 bucks on Amazon. I have this one and am very happy with it. Amazon.com: Auto ranging AC/DC Digital Clamp Meter: Home Improvement
I agree that a Clamp Meter would be handy. I used one a few decades ago and would have to buy one now. My Dad had access to one a long time ago.
Your point that a 0.5 amp draw would kill the house batteries in a week or so is very useful. I didn't know how few amp hours I have in those house batteries. I can imagine there are several components in the RV that might come up to more than the 0.5 amps.
In terms of blame if the batteries were actually frozen, that is an interesting question of responsibility. The dealer put the new RV into inventory in November and drove it to an RV show in January where we executed the purchase. One of the terms of purchase was that they would store until Spring, giving me time to arrange storage and get an airbrake licence. They did winterize it, so they clearly know about the importance of keeping batteries up. It is not obvious to me that I had the responsibility of actually telling them to keep the batteries charged – they had a whole lot full of RVs and should be experienced in taking care of the batteries.
Overall, it may well be that they weren't frozen over the winter. I'm still a little surprised that the chassis batteries died, because I can't see what would draw on them if the lights are off.
I'll wait to see the results when I pick it up after the warranty work is finished. And, clearly, I do need to use the cutoff switches when I store it.
Thanks to all for your advice.