Chassis battery / Freightliner lightbar

[jswickard]

I seem to be caught between two alternatives, neither of which I like very well. My coach is a 2011 Newmar Ventana on a Freightliner chassis.


When I have my coach in storage, with the chassis battery switch left on, there are enough parasitic draws to fully drain the battery in about 3 weeks. If I switch the battery off, it doesn’t discharge, but then, the next time I use the coach, I find that the Freightliner lightbar shows the date and time that I turned the switch off, rather than the current date and time. Thus I have to go through the process of resetting it every time I use the coach.



I don’t seem to remember that the Freightliner lightbar stopped counting with the battery off before I had it replaced (because of a compass problem), but then there a lot of things I don’t remember. The service facility that did the replacement says this failure to count is normal when the switch is turned off. I don’t understand why the lightbar is not able to count up the elapsing time if it has enough of a power source to retain the rest of its memory. A friend claims that this doesn’t happen on his Phaeton. Do others have this same problem?



Does anyone have a suggestion of how to avoid having to pick the lesser of these two evils? My storage facility does not offer the option of plugging in any auxiliary electrical component.

[Luv2go]

I assume it is inside, otherwise the small solar panel they usually put on Newmars should keep the chassis battery from draining.

As far as the clock remembering it's setting but not counting, this may have been a design decision made by the manufacturer of the chip in the ECU that keeps the time. Basically it takes a lot less power to keep a memory location powered up than to run a crystal and count clock pulses, so when the supply voltage goes low they first turn off all clocks in an effort to preserve the memory contents. It is also possible (unusual, but possible) they use nonvolatile memory to store the time, it does not lose it's memory when powered off.