Off-grid, full-time power can be a challenge.
The van is equipped with:
3 one hundred amp hour lithium batteries
2 roof-mounted solar panels, providing a total of 620 watts of solar
30 amp shore power external input
Alternator charging- started with charging from the factory alternator which would begin to charge the house batteries after the van was safely started, but then upgraded to the Nations Dual Alternator kit with 280xp amp with Balmar Max Charge Regulator for faster charging
The three house batteries power:
Inverter 35 watts
WiFi Ranger 30 watts
weBoost ~30 watts
roof fan 10-20 watts
Espar heater burns diesel but still uses some power ~25 watts
hot water generation pump ~10 watts
radiant heat pump ~10 watts
Aux heater fan/pump ~50 watts
Freshwater pump ~60-70 watts
Accumulator ~ 50-60 watts
Shower pump ~50-60 watts
Isotherm double drawer, fridge/freezer combo ~ 1100 watts/24hrs
Laptops ~ 130 watts
The solar panels don't usually recharge the batteries at that rate, mostly just due to available daylight hours. As shown on the graph below, even with a solid nine hours of daylight, the pannels only replenish one and a half batteries, and the daily load could consume that, meaning there isn't much left to store in the batteries to get through the night or a grey tomorrow.
The Charge Controller is by OutBack, and is paired with their Communication Manager so the system can be monitored with their Mate 3, which feeds into the Optics RE graph online. There is also the Victron battery monitor, which has a convenient app for realtime monitoring.
Lithium batteries are solid, but once you hit a certain point, they plummet fast. Through observing my system, that knee is at 12.6 volts. If I don't rapid charge within an hour, the system will shutdown. That plummet point usually happens at night, or on a grey day when we are working outside of the van; basically it's never good timing and having to fret over the batteries is no fun.
This means I was constantly searching for a place to plug in, which didn't feel very off-grid. That's why I installed the second alternator, and now just driving or idling a bit (less than an hour) can give the batteries enough of a top-up.
I am not a solar expert. The solar system on the van was installed and worked on by Sprinter Tech and Tiny Watts Solar. It took a while before the power wasn't something that had to occupy much of my day.