by troubleScottie » Sun Mar 06, 2016 6:11 pm
Use the search function to look for wiring diagrams. Lots here.
Basically all the wiring from the fuse box to the devices eg lights, pumps is the same no matter what you do. The same for the connection from the battery to the fuse box. This is what you might see typically in an automobile. Using 14awg wire is most likely fine. You do not have too many or any large draw items except the pump. You need a bigger gauge wire for the fuse box - battery connection. You might/should consider a master switch to disconnect all the TD loads from the battery.
Where the big decisions are is with the charging system for the battery.
You should get a multi-stage charger for the battery. The amperage to some extent determines how fast you can charge the battery. Chargers can be separate or incorporated into a power distribution box eg DC fuses, charger and AC circuit breaker panel. Either way, the charger directly connected to the battery.
The charger needs to be connected to shore power or a generator or some AC power source. Lots of methods. The major question is how elaborate or safe you want to be. Some people just use extension cords and gcfi outlets/surge protectors. You need to think about how to get the power cord out of the trailer or tongue box to the shore power/generator. And size of the power cord ( 50A/30A/20A/15A). For your example, something like 20A should be great (the charger can be a big draw). Remember it might be raining/snowing/windy and you might not be around all the time, so security and safety is part of the issue eg you probably do not want to leave your TD rear hatch open or the side doors or even the tongue box open as it invites problems. Circuit breakers between the shore power are also a good thing. RV parks are not known as the most reliable power source. And given a generator is outside in the weather, circuit breakers are good to protect against issues with the external power cord.
To charge from the Towing Vehicle (TV), you need minimally a large gauge wire (well 2, ground and positive) from the TV electrical system to the TD battery. It can be integrated into the wire harness (7 wire) or run separately. Again you should consider fuses at the positive terminals for both batteries and a continuously on solenoid to disconnect the TV when it is not running or you do not want to charge the TD.
Once at the TD, you have options.
Some people just connect the wires to the battery. You are depending on the TV charging system to regulate the charge on the TD battery.
Some people suggest a DC-to-DC charger which helps give you the max charge available to the battery and is often a multi-stage charger. Often they can serve as a solar controller also. Something like CTEK D250S.
There is another school of thought of having the TV DC system connected to an inverter to generate AC which then is used to connect to the battery chargers. In this system, the charger is connected to either the inverter or shore/generator. You most likely need an automatic relay to either use the inverter or the shore power. Although this system is not as efficient, it has some merits including price.
Solar, if you do not have a DC-to-DC charger, requires some sort of controller to regulate the power from the panels to the battery. The best plan is a mppt controller like Victron Energy MPPT 75/15 Solar Charge Controller. Again, there are cables leaving the TD going to the solar panels.
All the chargers, controllers, fuses, switches should be close to the battery.
If you look at this, the battery has up to 4 connections -- up to 3 inputs plus 1 output.
If you have multiple battery banks ( too elaborate??), there are still more components.
Michael Krolewski
Scottish Terrier Fancier
