Converter and Battery Question

BFL13 wrote:
The battery neg wire to frame still goes to the frame. The neg wire from the solar controller goes to the battery.

When the converter is unplugged you still get 12v from the battery. The converter only works if you have 120v from shore power or generator. (it also works from the inverter, but you don't want it to or you get that infamous "loop")

You can just buy a deck mount converter and put it up with the inverter and battery bank and leave the original converter where it is. No big wiring job. Put the controller in there too.

The battery bank needs a vented box because you don't want the inverter and converter to get ruined by battery fumes or the fumes to get a spark from the inverter. AGMs get around all that.

Good to know. I plan on either AGM or LifePo4 drop in equivalents at this point for the batteries.

The battery can be grounded to the frame wherever it's convenient to do so. With a solar controller, that doesn't need to change for any reason; the battery negative side of the controller can likewise be connected to a convenient chassis ground location (not necessarily the same one as the battery). The frame does provide a good, low-impedance path for the current, provided the connections to it are good and clean and tight. You'd be hard-pressed to create a better, lower-impedance connection with a wire in most cases.

Any halfway modern system will basically have the converter, the battery, and the DC fuse panel connected in parallel, ignoring the battery disconnect switch for the moment. This may be physicallly accomplished by having the converter connect to lugs on the DC distribution panel, basically making it be the junction point for all three, but electrically it's equivalent in theory. Others have the converter wired more or less directly to the battery lugs, or perhaps to some intermediate bus bar or other junction point. In any case, the converter does supply power not only to the battery but to the rest of the 12V system when plugged in, since they're all interconnected. A standard battery charger clamped to the battery would do the exact same thing, for the same reasons. You continue to have 12V power when unplugged simply because the battery is now carrying the load, and you have a working battery.

The specific details of what connects together physically and in what locations is somewhat more variable than the basic electrical setup. Fiddling around with those connection points is perfectly reasonable, provided of course you employ appropriate electrical safety practices, such as making sure sufficient overcurrent protection (fuses) are there for the circuits you reroute.

It is perhaps worth observing that modifying the converter connections may alter how the system behaves if the battery disconnect switch is used to disconnect the battery. If the converter is connected to the electric panel (or anywhere on that side of the switch), then it will power the 12V system when the battery is disconnected but not charge the battery. If it's on the battery side, then it would charge the battery but the 12V system for the RV would have no power. Neither one is especially desirable in most situations.

The battery neg wire to frame still goes to the frame. The neg wire from the solar controller goes to the battery.

When the converter is unplugged you still get 12v from the battery. The converter only works if you have 120v from shore power or generator. (it also works from the inverter, but you don't want it to or you get that infamous "loop")

You can just buy a deck mount converter and put it up with the inverter and battery bank and leave the original converter where it is. No big wiring job. Put the controller in there too.

The battery bank needs a vented box because you don't want the inverter and converter to get ruined by battery fumes or the fumes to get a spark from the inverter. AGMs get around all that.

Your inverter should have both its wires connected directly to the battery.