[RV8R]

The original goal was to make the system as simple as possible. Having one switch that completely turns off the battery helps a lot with that. If there is a desire to switch off all loads while keeping the B2B/Solar charger combo on that is easy to do but IMO not necessary. It's all personal preference and how you want to use the system. The nice thing about the ON/OFF switch this way is that the LiFePO4's will be exactly where you left them if you turn the battery off and walk away from the van for 6 months. There is no need to charge the batteries in storage and Motor7's setup will go from 0% to 100% in 4 hours.

I use a Victron battery protect with the remote wires running to a small switch as my normal cutoff for all the 12v devices with the exception of the inverter. This lets me hit one switch and stop the 1/2 amp drain from the stuff I don't normally shut off like the Cerbo & Screen, USB chargers, etc. If you use that setup for $45 you also get a low voltage disconnect for everything in the van that will prevent tripping your BMS if you leave something on while the van is in the shade.

Here is my “Alternator Charge Circuit”. All fuses & switches & pretty simple IMO;

3 fuses & switches;

1) 4 position Blue Sea ,,, disconnect / charge both house & starter off 120vac converter / power to Parallax via house or starter battery alternator / can use the house as a jumper battery (I don’t)

2) Cyrix230 “electronic smart solenoid ,,, disconnects the starter battery under it’s factory set voltage readings “bidirectional”

3) Driver’s controlled ground switch to manually turn the Cyrix on or off.

So our standard “use” is;

storage mode Blue Sea is in the “OFF” position

Using the Van ,,, Blue Sea is on “1&2 or BOTH”. Then we turn the alternator charging ON or OFF from the Driver’s seat.

House AGM batteries are monitored on the iPhone via “Bluetooth” ,,, all upfront in the cockpit.

 

[dog_house]

Here is my “Alternator Charge Circuit”. All fuses & switches & pretty simple IMO;

Same here but with a slightly different switch that's a little simpler to understand for users. Off/On/Combine. This lets us run the house off the van battery if things are cold or dead and also jump start or charge the van if needed.

 

[Motor7]

Wow, tough to follow this very active thread!

In any event, in answering our question as to the purpose of the switch, you didn't mention the MPPT controller. Of course, depending on where you 'tie-in' the MPPT controller, that switch will also switch-off the MPPT controller or it won't. We don't understand the need for switches to disable apparatus in the first place. In our system, we can disable each of the devices, e.g. our MPPT controller, our shore charger/power, and our inverter, at each respective device without need for any switches.

But in determining your wiring and switch locations, we think additional answers are required such as "why do you want to switch-off your inverter/charger?" And, if switched-off, do you want to lose charging from your MPPT and alternator at the same time? Indeed, if you're into external switches (again, as opposed to merely activing/de-activating each device at the device, itself), maybe you need multiple switches - - one for the inverter charger, one for the MPPT and alternator? And, by the way, are there times that you'll want to independently switch-off your solar panels? Your alternator?

I completely understand what you are saying, and using the device's own switching to turn them on and off make sense. I am only considering introducing an external switch to take the place of the pos busbar....since I need to join the 12v from the batteries, the mppt, the fuse panel & Inverter. I "think" I am ok turning off the batteries and mppt controller at the same time, but until I start using my 'system' I really don't know if I am going to use that feature/like it or not. At least for now, I think I will just try it & can start putting all of this together,.... if it is not a fatal error, which is why I have you fellow inmates here keeping me from doing something really stupid👀.

Btw, where do find it best you start building the system, I mean starting with which component, or does it matter that you start with the solar panels, or the batteries, or the Shore power, or,or,or......?

 

[dog_house]

I completely understand what you are saying, and using the device's own switching to turn them on and off make sense. I am only considering introducing an external switch to take the place of the pos busbar....since I need to join the 12v from the batteries, the mppt, the fuse panel & Inverter. I "think" I am ok turning off the batteries and mppt controller at the same time, but until I start using my 'system' I really don't know if I am going to use that feature/like it or not. At least for now, I think I will just try it & can start putting all of this together,.... if it is not a fatal error, which is why I have you fellow inmates here keeping me from doing something really stupid👀.

Btw, where do find it best you start building the system, I mean starting with which component, or does it matter that you start with the solar panels, or the batteries, or the Shore power, or,or,or......?

The only thing you can mess up at this stage is forgetting a wire and building a wall where it needs to go. Once you have the locations of the components figured out just start running wires. Don’t forget to label them on both ends to make your life easier later.

If you are not using marine style wire that has a jacket over the wires be careful with sharp metal edges and protect the wires as you run them through the van.