bill and jody,

We don't have an "Echo Charger" or trickle charger for our coach's chassis batteries. Marathon doesn't routinely install them. Our first coach, (CC XL 2 slide) had an Echo Charger.
We throw some breakers in our 2000 Marathon "H", curbside compartment nearest the tag. There are 3 breakers we trip that cut the 12 volt drain on the chassis batteries. It has taken 3 busses and 2 of which were Marathons to be told this trick. Now, if the coach needs to sit for more than 3 weeks, we trip the breakers and the chassis batteries don't drain flat.