Budget cabin 12V starter
12V system, designed for a -25C (-13F) cold snap - saved 2026-07-04
Compatibility checks
infoArray is oversized for the controller - output will clip at ~768WArray size vs controller charge output
The array can push 62.5A but the controller tops out at 60A. This is common and usually fine: you harvest more in mornings, evenings, and winter, and the controller simply caps peak output. Verify the controller's max array wattage is not exceeded (separate check).
Array = 200W x 4 panels = 800W Potential charge current = 800W / 12.8V = 62.5A Controller rated charge current: 60A
10 passing checks - expand to see the math
passBattery matches the 12V systemSystem voltage coherence
Renogy Core Mini 12V 100Ah (12.8V nominal) is a 12V-class battery.
battery nominal 12.8V is in the 12V class == system 12V
passInverter matches the 12V systemSystem voltage coherence
Renogy 2000W 12V Pure Sine Wave Inverter (RNG-INVT-2000-12V-P2) DC input is 12V-class.
inverter DC input 12V is in the 12V class == system 12V
passCharge controller supports 12V banksSystem voltage coherence
Renogy Rover 60A supports 12/24/36/48V battery banks.
controller battery voltages [12, 24, 36, 48] include 12V
passString Voc stays at 50.1V at -25C - under the 140V limitCold-temperature string voltage
2 x Rich Solar MEGA 200 200W 12V Monocrystalline Solar Panel in series stays below the Renogy Rover 60A max PV input voltage at your design low temperature.
Voc_string = Voc x N_series x (1 + tempCoeff/100 x (T_design - 25))
= 21.80V x 2 x (1 + (-0.3%/100) x (-25 - 25))
= 21.80V x 2 x 1.1500 = 50.1V
Controller max PV input: 140VpassString Vmp 36.8V has healthy margin over the 12V bankMPPT voltage margin
Clears the start floor cold and the hot-weather floor with sag included.
Vmp_string = 18.40V x 2 = 36.8V Start floor = V_batt + 5V = 12 + 5 = 17V Hot Vmp (~11% sag) = 36.8V x 0.89 = 32.8V vs hot floor 20V
passArray 800W is within the controller's 800W rating at 12VMax array wattage for battery voltage
Within the published maximum array wattage.
Array = 200W x 4 panels = 800W Controller max array wattage at 12V: 800W
passRenogy Rover 60A supports LiFePO4 chargingBattery chemistry support
Controller has a lithium profile or user-adjustable charge voltages.
battery chemistry = lifepo4; controller lifepo4_profile = true
passBank BMS limit 200A comfortably covers the inverter's 156.3A drawInverter draw vs battery BMS limit
Healthy headroom at full inverter load.
Inverter draw = 2000W / 12.8V = 156.3A Bank BMS limit = 100A x 2 batteries = 200A Headroom band starts at 80% of limit = 160A
passBank BMS peak 400A covers the inverter's 312.5A surgeInverter surge vs battery peak limit
Surge loads within the bank's published peak rating.
Surge draw = 4000W / 12.8V = 312.5A Bank BMS peak = 200A x 2 batteries = 400A
passCharge current 60A is within the bank's 100A capacityCharge current vs bank capacity
Charge rate within limits.
Controller rated charge = 60A Bank max charge = default 0.5C x 100Ah x 2 = 100A (manufacturer max not published)
2 checks not run (missing published specs)
not checkedNot checkedArray current vs controller input limit
Renogy Rover 60A does not publish a PV input current limit in our data. MPPT controllers generally current-limit safely, but verify against the manual.
not checkedNot checkedBattery parallel count
Renogy Core Mini 12V 100Ah does not publish a max parallel count in our data. Verify with the manufacturer before paralleling 2 units.
Parts list
| Part | Qty | Est. price | Where to buy |
|---|---|---|---|
Rich Solar MEGA 200 200W 12V Monocrystalline Solar Panel | 4 | $680 | |
Renogy Rover 60A | 1 | $260 | |
Renogy Core Mini 12V 100Ah | 2 | $534 | |
Renogy 2000W 12V Pure Sine Wave Inverter (RNG-INVT-2000-12V-P2) | 1 | $369.99 | |
| Estimated total | $1,843.99 |
Wire and fuse guidance
| Segment | Continuous | Run (one way) | Copper wire | V-drop | Fuse/breaker |
|---|---|---|---|---|---|
| Array to charge controller | 23.2A | 25 ft | 8 AWG | 1.98% | 30A |
| Charge controller to battery bank | 60.0A | 5 ft | 4 AWG | 1.16% | 80A |
| Battery bank to inverter | 156.3A | 4 ft | 3/0 AWG | 0.60% | 200A |
Array to charge controller: show the math
Continuous current = 23.2A Design current = 23.2A x 1.25 (NEC continuous) = 29A Wire: 8 AWG copper (75C ampacity 50A); voltage drop 1.98% over 50ft round trip at 36.8V (target <= 3%) Fuse/breaker: next standard size >= 29A -> 30A
Charge controller to battery bank: show the math
Continuous current = 60A Design current = 60A x 1.25 (NEC continuous) = 75A Wire: 4 AWG copper (75C ampacity 85A); voltage drop 1.16% over 10ft round trip at 12.8V (target <= 3%) Fuse/breaker: next standard size >= 75A -> 80A
Battery bank to inverter: show the math
Continuous current = 156.3A Design current = 156.3A x 1.25 (NEC continuous) = 195.3A Wire: 3/0 AWG copper (75C ampacity 200A); voltage drop 0.60% over 8ft round trip at 12.8V (target <= 3%) Fuse/breaker: next standard size >= 195.3A -> 200A
Use a Class T or equivalent fast DC-rated fuse close to the battery positive terminal.
Sized for 75C copper ampacity with the NEC 1.25 continuous factor and a 3% voltage-drop target. Round up when between sizes and verify against local code.