Originally Posted by cullengw
. . . I have been doing research on charging laptops and realized I'm a dope.
Laptop is powered by battery (DC), when you charge it you use an adapter for the (AC) plug. So why would I want to go from a DC battery to an AC inverter to a DC battery again. lol I mean unless certain laptops cant get the dc charging cable.
Most laptops use about 18 Volts DC out of the adapters to charge the internal batteries, even if the batteries themselves are only 12 Volts. You can get special automotive or airplane DC-DC switching converters to charge them, but they are pricey.
Also, you will find many if not most laptops communicate with their adapters through the power cord. They refuse to work with unknown adapters, even if the voltage and plug are identical. I had one mobile converter stop working years ago when I added a quick-disconnect in the middle of the factory cable from the "brick" to the computer plug, because it impeded the communications transfer embedded in the DC.
I found it was better and much cteaper to get a small inverter just for the correct AC laptop charger, than to get the correct DC-DC charger (unless your employer has a stack of them to hand out
). Just switch the inverter (and all other loads) completely off when not in use, to prevent "phantom loads" from draining your battery.
Example of a phantom load: A TV set that can be turned on by a remote control is always
using power to run the sensor that is waiting for the "on" command. To save electricity, plug the set into a power strip and turn the strip off when not in use. Off-grid homesteaders get religiously fanatical about not leaving cell phone chargers plugged into AC when the phone is disconnected, because every little bit of electricity saved is more battery run time.
Originally Posted by cullengw
. . . At an RV campsite with a power hook up.....how does that work :P :P :P do you like hook it up to your batteries? or do you like have a seperate circuit for that?
There are AC outlets at campgrounds, you plug your bus into the AC and you provide your own battery charger or "converter" inside the bus.
There are three basic types of campground AC power connections. The first of the two main ones is the "30 amp RV," which is a 3-pin 125-volt connection. It is good for a maximum of 3750 watts. There is a round safety ground, and the hot and neutral are slanted like old dryer or stove outlets.
The second common type at bigger campgrounds is the "50-amp." This is a 125/250 volt four-pin connection. Assuming the receptacle is correctly wired for 250 volts, it can provide 12,500 watts, up to 50 amps on each hot leg. If the outlet happens to be mis-wired with both hot legs on the same phase, cut that in half or else the neutral would be overloaded to 100 amps. Measure each outlet with a meter before plugging in. This style plug has three blades in parallel plus a U-shaped safety ground.
The final type is a 15-amp or 20-amp outlet similar to what you see on the wall at home. The plug with two parallel blades and a ground is for 15 amps. 20-amp plugs and outlets are SUPPOSED to have one blade turned perpendicular to the other, but often 20-amp cords and receptacles will have the common 15-amp parallel blades. Receptacles for 20-amp circuits will sometimes have one T-shaped hole that will take either a 15-amp or 20-amp 125-volt plug.
Campground pedestals may have all three types of outlets present plus a miniature circuit breaker load center built in, or they might be much simpler with only a single choice.
If you limit your bus AC power to 20 amps, and carry a 12/2 shoreline or extension cord with a 15-amp plug on the end, you can plug into any standard outlet, plus you can get a "hockey puck" adapter for a couple of bucks to plug the cord into a 30-amp RV receptacle if that is all their is.
If you are adding an air conditioner or other heavier load, you might install 30-amp service and carry a dedicated 10/2 shoreline. If you are installing dual air conditioners, or using an electric stove, water heater, or hot plate, then you might want to wire for the full 50 amps and carry a heavy 6/3 shoreline.
If you wire for 50 amps and encounter a campground with only 30 amp service, there are pigtail adapters that allow your 4-prong shoreline to plug into a 3-prong socket. Just be sure to turn off breakers for heavy loads, because the outlet is only able to supply 30% of the power the big cord could carry.
Note: If you put in a fuse box or circuit breaker panel, you MUST isolate the white neutral wires in your bus from ground. Neutral is only tied to the safety ground at the main campground or home disconnect, not in your mobile sub-panel. And if you happen to plug into a GFCI ground-fault protected circuit, having the neutral and safety ground tied together will trip the GFCI RIGHT NOW.