Whilst wiring up the new battery last year I used quick release battery terminals. I did this so that I could disconnect them easily, however I have recently come to the conclusion that I have never actually needed to nor have I in actual fact ever needed to do this. I am about to start rewiring that section of the van so decided to see if I could make my life easier. When you live in your motorhome fulltime you have to anticipate all conditions that can affect you. This means having multiple methods of charging your leisure and cab batteries. Making this as easy as possible is important so that you are not caught out.
Current Set up
Currently my battery is connected to a battery isolator switch like this. From the other side of this terminal I have multiple wires running, 1 to my Battery Charger, another to my Solar Charge Regulator, another 2 to my fuse box/distribution box and yet another to my Inverter. This isolator switch has about as many ring terminals connected as is possible and it looks a bit nasty to be honest.
The cable that goes to the inverter passes through another isolator switch so both need to be on to power the inverter. This is a bit wasteful. The next thing to note is that my Sterling Battery to Battery charger (B2B) is not connected currently because the terminals on the 35mm cable are different due to a change of leisure batteries.
The reason for the upcoming rewire is that I also have a battery master which will take excess charge from the leisure battery/solar panels and top up the vehicle battery. I also want to reconnect the B2B charger and put an isolator switch in solar panel input. Finally I have a CTEK MXS5.0 charger which I want to permanently wire in.
The wiring plan
My plan is to wire the battery master across the B2B charger. This is the easiest way to do this. While I am doing this I will reconnect the B2B charger, however I need to be able to disconnect this when the the CTEK charger is powered up. So this means a Battery isolator switch on the input to the B2B.
I also don’t want to be connecting the B2B via the battery Isolator switch, rather I want this connected directly to the Battery (via a fuse). I did a search for battery terminals that would allow me to connect multiple cables. I need it to be able to accept three cables with each one fused.
- Battery to Battery Charger.
- Isolator switch for main electrics.
- Inverter Supply.
It took a bit of hunting around for a solution but I finally came across these.
So I will connect the Main terminal to the B2B charger and the Battery charger via a mega fuse. Neither of these devices need to be isolated on this connection.
Then one of the two smaller terminals will be used to supply the fuse box via an isolator. The third terminal will have the solar panel charge controller connected and the cable that goes to the isolator for the Inverter.
This combination of connections means that everything that needs isolating from the battery can be done so with a single isolator switch. All connections will be fused right at the battery with mega fuses.
When I am driving I can flick one switch to turn off the solar panels to allow the B2B charger to do it’s job. When parked up without hookup the solar panels will keep the cab battery topped up via the battery master. When parked up with a mains hookup I can isolate the B2B and turn on the CTEK charger. A future job will be to automate this with a 240V relay. So when a hookup is connected a relay will automatically disconnect the B2B and power supplied to the CTEK.
I am planning on doing this job on either Monday or Tuesday next week once I know the results of the MOT. If it fails badly and not feasible / practical to repair there is no point doing this work… If I go ahead with it I will take pictures and document the job.