Parasitic voltage due on Roadtrek 190

senf wrote:
I hear you 'Booster', but on my RT the separator wiring to the inverter/charger and then to the coach batteries is the same size as the separator wiring to the chassis battery.

One of two stated purposes of the separator is to allow the coach batteries to assist the chassis battery in starting. The separator can be wired either for automatic assistance via the start switch or (as I have it) a separate switch on the dash. When I use the switch on the dash, you can hear the separator relay engaging and disengaging.

The other stated purpose of the separator is to allow the coach battery to be charged when the engine is running or the chassis battery to be charged when on shore power or generator. In both cases if either battery gets too low, the separator separates the two circuits to prevent the power draining from the higher of the two batteries.

All good stuff - when it works!!!

If yours is wired adequately to start off the coach batteries, it is not like any of the Roadtrek wiring diagrams. This is entirely possible due to the sorry state of the Roadtrek literature:B. Remember that the wiring to the separator and the converter, the wiring from the alternator to the starter battery, and the wiring from the converter to the coach batteries is not carrying starting amperage normally, which is only in the wiring from the starting battery to the starter. The alternator is in the 150 amp range, the converter 30-50 amps. If yours is wired as the wiring diagram shows, you should have 4 gauge to the converter and coach batteries, with 80 amp breakers. The breakers will trip on starting amperage which is usually in the 150-300 amp range depending on temperature and engine. The 4 gauge is also way to small for that length an will have a huge voltage drop and heat gain. For that distance, you probably would want a 1/0 cable to be safe and 300 amp fusible link. I think Roadtrek wired the separator without the boost start for a reason, and the reason is that it isn't wired for it.

One of the stated purposes of a separator is using it for starting off either set of batteries, but it is always stated that only activate that feature if adequate wiring and protection are provided.

I would be very interested to see if Roadtrek has changed the wiring in their units, as boost would be a very nice feature, but it would increase their costs and be heavier, so they probably wouldn't do it.