Power Management

Connecting the battery

battery1 (1)One of the most misunderstood parts of small trailer camping is power or battery management. Let’s start with how a trailer battery is hooked up as it can seem confusing because there are so many wire connections to the battery posts. There are usually 4 wires that connect to the battery. One set comes from the solar connector coming from the top of the plastic battery box. One is red and one is black. The RED wire will connect to the + terminal on the battery and the BLACK wire will connect to the – terminal. Next there will be two wires coming from the trailer loom. The white wire will connect to the – terminal and the Red wire will be crimped on to a yellow wire that has an in-line fuse.

Little Guy Trailers | Converter Box

This red/yellow wire will connect to the + terminal on the battery.


battery openA-liners and some of the trailers that do not have the solar connector wires will follow the same basic rules. The wire coming from the trailer that has the in line fuse (this time it is a white and black wire) will connect to the + terminal. The remaining two white wires will connect to the – terminal.

So basically, find the line with the fuse and connect it to the + terminal. If there is another red wire, connect it to the + terminal also. All other wires go to the – terminal.



battery1 (2)Fuses protect the trailer wires and electronics from surges or improperly hooked up batteries. The first fuse to check if things are not working is the fuse at the battery….remember the one that is connected to the + terminal. I usually leave it hanging out of the plastic battery box for easy access. I also take this fuse out when I store the trailer for an extended period of time to keep the converter box (1)battery from running down. Stereos, CO2 and smoke detectors can draw from the battery while in storage and cause it to go dead. The next set of fuses is in the converter box. While under battery power, you will be using the colorful car type fuses on the right. If one is “blown”, there should be a red LED light next to converter box2the bad fuse. The circuit breakers on the left are like the ones at your house. Just flip them back on if they pop off. These are the protection circuits breakers for when you are plugged in with a power cord. The breakers should remain in the on position all the time.

Here is the catch….your two systems are separate. The household plugs will only work when you are plugged into an outside power source. When you are not plugged in or using a generator only the 12 volt items will work. When you are plugged in, the converter box will charge the battery.

Plug in power vs. 12 volt power and solar.

To use your household type plugs, you will need to be plugged into a 110 power source…ie; household plug or a generator. Air conditioners, microwaves, hair driers all need the power source. Most small trailers will have a 30 amp power cord that you can plug in. The end of this cord looks like the cord you have on an electric dryer but it is not the same. It will plug into campsite power sources or you can get an adapter that will allow you to plug into a regular household plug. In A-liners remember to switch your power source off 12 volt to 110 or gas whenever you can so you do not run your battery down quickly. The round “cigarette lighter’ type plug will be for charging cell phones or running any 12 volt accessories. This will be using the power from your battery. Solar panels will be replacing power into your battery….not actually running any devices. Larger the solar panel, faster your battery gets recharged. Finally when you are plugged into your car if you have the round 7 connector you will be able to charge your battery while driving….just like you charge your car battery. This charge is more of a maintenance type charge and will not be great for bringing back a dead battery. Start your trip with a full battery for best results. If you only have a flat 4 connector you will only be powering your trailer running lights and turn signals….no charge to your battery even with an adapter.