LD1
Epic Contributor
Charging from the truck is SLOWWWW.I have had two Pequea dumps, one 5000 pound single axle, and one 10,000 pound duel axle. Since they both have brakes they have 7 pin connectors. They both charged the battery from the truck. Turned out a friend in PA had the same C1500 10,000 pound trailer and his was 15 years old with the original battery, still dumping. I guess in theory, his battery could be just about shot, but just driving from one location to the next, could build enough juice to dump it.
Its like a 12 gauge wire running from the front to back, through the 7-way.....and a few more feet to the battery. Try to pull any amperage at all and the voltage drop quickly gets you so it wont charge.
Think of voltage in terms of pressure and amps in terms of flow (comparing to something like a garden hose).
If you dont EXCEED the voltage of the trailer battery....it aint gonna charge. Getting 12v at a 7-way with voltage drop and puling very little current.....aint charging.
And it also depends on how the TRAILER is wired. Most trucks protect the 12v AUX wire with a 30A fuse. And most dump trailers have a fuse as well....or sometimes a breaker. But on the low end dump trailers....you can easily blow the truck charge fuse by simply trying to dump and leaving the 7-way hooked to the truck. You can blow that fuse...and never know it til trailer wont dump and you scratch your head wondering why it didnt charge on your last trip.
There is a way to wire it with a little relay that will isolate the truck when dumping so that never happens. But most manufactures dont do that.
But if you are dumping heavy.....full cycle loads.....a 15 min trip is NOT enough to replenish what was used. And if you work it all day.....you may end the day with a trailer that wont dump