question

IMHO, connect BOTH to the battery (through shunt if applicable) through shortest path possible. Wiring between RV converter and battery is usually marginal at best, so you have issues with voltage drop.

Assuming you have SmartSolar MPPTs with bluetooth. If they are BlueSolar, none of the networking/bluetooth stuff apply.

Should show up as a second MPPT on Victron Connect.

Network them in a VE.Smart bluetooth network to have them coordinate charging with each other. Not explicitly needed, but it's a cool feature.

Breaker between MPPT and PV should be based on wiring, array configuration and panel fusing requirements (on panel label). No need for two pole breaker. If 4S or 2S2P array, no need for fusing/breaker. If 4P, each panel should have its own fuse/breaker.

Need wiring for 30A between each MPPT and battery and 40A fuse/breaker. Make sure you size the wire for both current and voltage drop due to length.

Need ONE of the following for voltage/temperature sensing:

1. smart battery sense
2. Smartshunt with temp sensor
3. BMV-712 with temp sensor

Any of the above can be added to the same VE.Smart network to provide direct measured voltage and temperature to the MPPTs.

Thank you for the info.

I don't think that the solar panels have any sort of fuse or breaker between them and the MPPT controller.

Should I add some sort of fuse up on the roof? If so what type and how are they connected? There isn't a typical box up on the roof with room for anything like fuses or bus bars.

The only thing on the roof are two double ports with MC4 connectors coming out for hooking to the panels.

I'm thinking that I should have a fuse for each individual solar panel? Four in total for the four 100 watt panels that are up there.

Is there some sort of an inline fuse that is made to go between the MC4 connectors on the roof and the solar panels?

If your panels are in series, your PV voltage will typically be about 68-88V. If they are in parallel, PV voltage will typically be 17-22V.

If the panels are in series, they do not need any kind of fusing, but you may add a fuse or breaker if you choose.

If they are in parallel, each panel needs a fuse consistent with the panel's fuse rating on the label.

Yes, there are MC4 inline fuses, and they would likely be the easiest unless you already have a combiner box joining them. If the combiner box has fusing options, that's the best route.

Fuses/breakers between the MPPT and battlery should be at the battery, not the MPPT. Overcurrent protection is to protect wiring from a short and the most current will flow from the battery. The MPPT will be current limited so no need for overcurrent protection at that end.