Cloning: Budget cabin 12V starter
Pick parts across brands. Every compatibility check shows its math. Save to get a shareable link.
Solar array
Panels + how they are wired (series x parallel)
Charge controller
MPPT/PWM between array and battery
Battery bank
Identical batteries in parallel
Inverter / all-in-one
DC to AC. All-in-one units include the charge controller.
Wire runs
One-way distances for wire and fuse sizing.
| Segment | Continuous | Run (one way) | Copper wire | V-drop | Fuse/breaker |
|---|---|---|---|---|---|
| Array to charge controller | 23.2A | 25 ft | 8 AWG | 1.98% | 30APV-rated (gPV) fuse or DC breaker |
| Charge controller to battery bank | 60.0A | 5 ft | 4 AWG | 1.16% | 80AClass T |
| Battery bank to inverter | 156.3A | 4 ft | 3/0 AWG | 0.60% | 200AClass T |
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: 30A - two criteria, both required: carry the load: fuse >= design 29A -> next standard size = 30A protect the wire: fuse 30A <= 8 AWG ampacity 50A - OK construction: PV-rated (gPV) fuse or DC breaker
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: 80A - two criteria, both required: carry the load: fuse >= design 75A -> next standard size = 80A protect the wire: fuse 80A <= 4 AWG ampacity 85A - OK bank BMS continuous 200A >= fuse 80A: the bank can hold the fuse's rated load construction: Class T (interrupt rating matters on battery mains)
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: 200A - two criteria, both required: carry the load: fuse >= design 195.3A -> next standard size = 200A protect the wire: fuse 200A <= 3/0 AWG ampacity 200A - OK bank BMS continuous 200A >= fuse 200A: the bank can hold the fuse's rated load construction: Class T (interrupt rating matters on battery mains)
Mount the fuse close to the battery positive terminal - it protects the wire run, so the unprotected stub should be as short as possible.
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.
Balance of system - shopping list
| Item | Qty | For |
|---|---|---|
| 8 AWG copper wire | 1 | ~60 ft total (25 ft one way, round trip + slack) - Array to charge controller |
| 30A PV-rated (gPV) fuse or DC breaker | 1 | Array to charge controller |
| 4 AWG copper wire | 1 | ~15 ft total (5 ft one way, round trip + slack) - Charge controller to battery bank |
| 80A Class T | 1 | Charge controller to battery bank - include the matching fuse holder/block |
| 3/0 AWG copper wire | 1 | ~10 ft total (4 ft one way, round trip + slack) - Battery bank to inverter |
| 200A Class T | 1 | Battery bank to inverter - include the matching fuse holder/block |
Derived from the wire and fuse guidance above. Wire lengths include round trip plus slack - verify against your actual layout, and verify ratings against local code. Buy fuses and wire from reputable electrical suppliers; marketplace listings for these items are a common source of counterfeit or mislabeled parts.
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 49.7V at -25C - cannot reach the 140V limit at any temperatureCold-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. This string cannot reach 140V at any physically possible temperature.
Why this matters: Panel voltage rises as temperature falls. A string that measures fine in summer can exceed the controller's absolute maximum input voltage on the first cold clear morning, which can permanently destroy the controller - and at these DC power levels, failures can start fires. This is the mistake experienced builders catch most often in DIY parts lists.
Voc_string = Voc x N_series x (1 + tempCoeff/100 x (T_design - 25))
= 21.80V x 2 x (1 + (-0.28%/100) x (-25 - 25))
= 21.80V x 2 x 1.1400 = 49.7V
Controller max PV input: 140V
Crossover: string Voc reaches 140V at T = 25 + (140/43.6 - 1) x 100/-0.28 = -764.6C (below absolute zero - never reached)passString 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 600A 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 = 300A x 2 batteries = 600A
passCharge current 60A is within the bank's 200A capacityCharge current vs bank capacity
Charge rate within limits.
Controller rated charge = 60A Bank max charge = manufacturer max charge 100A x 2 = 200A
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.
Saving creates a permanent link you can post anywhere. No account needed.