MultiPlus 24/3000/70-50
3kVA inverter · 70A charger · 50A transfer
Runs Cozy's 120V circuits from the battery, charges from shore power and transfers between sources.
Chapter 03 · Power core
Why Cozy was built around 24 volts.
A coordinated 24V system turns sunlight, shore power and time on the road into one large, usable reserve - while carrying roughly half the DC current of an equivalent 12V high-power system.
The complete system
Each component has one clear job.
The cards begin with what each part does. Model names and technical ratings remain available for readers who want the additional detail.
SmartSolar MPPT 100/50
100V PV input · 50A charging
Tracks the array's productive point and regulates solar into the 24V battery bank.
Orion XS 1400
12V alternator → 24V bank
Safely converts power from the Ford Explorer's 12-volt alternator into controlled charging for Cozy's 24-volt battery bank.
Lynx Distributor
Four monitored fuse positions
Distributes and protects the high-current positive side in one organized service point.
SmartShunt 500A
500A negative-side sensing
Measures battery current so state of charge, consumption and charging are based on the full negative return.
Cerbo GX
Victron data · VRM · Home Assistant
Collects system information for remote visibility and Cozy's Fire-tablet dashboards; it does not switch high-current power.
The system as installed
One small compartment. The full power core.
The component cards separate each piece so its purpose is easy to understand. This photograph shows how the same equipment actually fits together beneath Cozy's bed, with the four-battery bank below and the Victron charging, conversion, protection and monitoring hardware above.
The visible cabling is the working installation, preserved as photographed rather than rearranged for a staged picture.
4 Renogy Core Mini batteries24V high-power backbone1 coordinated electrical compartment
The energy reserve
Four batteries. Two series strings. One bank.
Each Renogy Core Mini is rated at 12.8V and 300Ah. Two batteries in series create a 25.6V string. Two equal strings in parallel create 600Ah at that system voltage.
Series pair A
12.8V
300Ah
+300Ah
12.8V
300Ah
300Ah
∥
Series pair B
12.8V
300Ah
+300Ah
12.8V
300Ah
300Ah
25.6V · 600Ah15.36kWh total storage
Installed under the bed
4 × Renogy Core Mini
12.8V · 300Ah each
Moving the energy center under the bed created room for the four-battery bank while freeing the original exterior battery compartment for future use.
The same 3,000W load
12V system≈ 250A
vs.
24V system≈ 125A
Idealized DC current before inverter losses. Actual current varies with battery voltage, efficiency and load.
Lower-loss inverting
The inverter can deliver the same AC power while the DC side carries roughly half the current, reducing heat and voltage drop.
Less copper
Lower current can allow smaller conductors or fewer parallel runs, simplifying routing, terminations and cable cost.
Right-sized system
The 3kVA MultiPlus and Country Mod A/C fit naturally on 24V, while a converter preserves the original 12V camper systems.
Three ways to charge
Roof solar
SmartSolar 100/50
The solar controller continually adjusts to changing light, then safely regulates charging into the 24-volt battery bank.
Campground
MultiPlus 24/3000/70-50
A 30A locking inlet feeds the camper. The MultiPlus passes power to 120V circuits and can replenish the battery through its 70A charger.
The road
Orion XS 1400
Buck-boost DC-DC charging converts the Explorer’s alternator supply into controlled charging for the 24V battery bank.
The roof array
Eight CalSun panels. 800 watts overhead.
Four panels form one uninterrupted front-to-back line on each side of the curved roof. Each panel meets the next along its short edge, exactly as Cozy's side profile shows.
8 panels100W each800W total4 + 4 roof layout
See the complete solar story →Roof side A · four panels in one line
Cozy’s lengthwise roof ridgeRoof side B · four panels in one line
Cooling
Two black rooftop units. Two different jobs.
Cozy does not ask one air conditioner to be ideal in every power situation.
Country Mod 24V A/C
Normally 300–500W parked
Efficient direct-DC cooling protects the reserve while providing real relief away from hookups. Higher draw can occur with conditions and operating mode.
Coleman-Mach 10 NDQ
13,500 BTU · ~1,500–1,700W
High-output 120V cooling is the right tool when campground power is available and the battery does not need to carry the full load.
What was preserved
Modern power did not erase the original camper.
A dedicated 24V-to-12V converter keeps the Casita’s original low-voltage systems in their native world. Lights, the water pump and ventilation fans continue to feel familiar while the high-power backbone operates at 24V.
Interior lightsWater pumpVentilation fansOriginal 12V circuits
Functional topology
One reserve, organized into clear paths.
PV → SmartSolarShore → MultiPlusExplorer → Orion XS
↓
Lynx +25.6V battery bank− SmartShunt
↓
24V A/C120V inverter loads24V → 12V originals
~42W
measured idle DC draw
300–500W
typical parked 24V A/C draw
1.5–1.7kW
typical shore A/C range
Operating figures are observed or typical values for Cozy, not guaranteed ratings. Wiring diagrams are conceptual; installed conductors, fuses, disconnects, grounding and service procedures must be verified before work.
Control, visibility and connection
Fire tablets
Replace a dedicated GX Touch with friendly whole-camper displays.
Combines Victron data with camper sensors, trends and alerts.
Extends remote awareness and real work beyond the campsite.
Tilty sensors
Translate pitch, roll and heading into useful setup guidance.