Traveling in the winter with a TT
We are considering traveling from Arkansas to Omaha, Nebraska in the next week or so. We are going to watch the weather, but, if the forecast is wrong. It would be nice to have some wisdom from expe...
Forum Discussion
The Bargeman Supply "+12V" does not normally have sufficient voltage to charge Trailer Batteries. In modern vehicles, the Alternator contains an electronic controller which adjusts output (Voltage, and therefore Amps) according to the measured "State of Charge" found via the "Sense" wire. For a short time after starting, the voltage WILL be sufficient to charge the batteries - but the "State of Charge" recovers pretty quickly, and the alternator reduces its voltage to a "float" level of 13.5 - 13.8V.
Even if all this voltage could be seen at the Trailer batteries, it's not enough to drive much current - and the batteries will not charge in a reasonable amount of time. But the situation at the Trailer batteries is even worse than that, for two reasons: Voltage Drop in the wiring, and lots of power being consumed by the refrigerator.
Typical RV refrigerators, built using heater-based "absorption" technology, consume 10-15A while running the DC Heater. While the refrigerator tries to draw this power, from both the Trailer batteries and the TV-Bargeman connection, the Voltage at the end of the wiring from the connection wiring by amounts which Internet "Voltage Drop Calculators" will estimate for you. "Voltage Drop" values of 5% and higher are not uncommon when the Fridge activates the heater. When the original "13.5V" drops below the Voltage available from the Trailer batteries, the Fridge will pull power from the Batteries instead:
They are being discharged, rather than charged.
Even if all this voltage could be seen at the Trailer batteries, it's not enough to drive much current - and the batteries will not charge in a reasonable amount of time. But the situation at the Trailer batteries is even worse than that, for two reasons: Voltage Drop in the wiring, and lots of power being consumed by the refrigerator.
Typical RV refrigerators, built using heater-based "absorption" technology, consume 10-15A while running the DC Heater. While the refrigerator tries to draw this power, from both the Trailer batteries and the TV-Bargeman connection, the Voltage at the end of the wiring from the connection wiring by amounts which Internet "Voltage Drop Calculators" will estimate for you. "Voltage Drop" values of 5% and higher are not uncommon when the Fridge activates the heater. When the original "13.5V" drops below the Voltage available from the Trailer batteries, the Fridge will pull power from the Batteries instead:
They are being discharged, rather than charged.
