Full-time vanlife 800W 24V
24V system, designed for a -10C (14F) cold snap - saved 2026-08-16
Compatibility checks
14 passing checks - expand to see the math
passBattery matches the 24V systemSystem voltage coherence
LiTime 24V 100Ah LiFePO4 (25.6V nominal) is a 24V-class battery.
battery nominal 25.6V is in the 24V class == system 24V
passInverter matches the 24V systemSystem voltage coherence
Victron Energy MultiPlus-II 24/3000/70-50 120V DC input is 24V-class.
inverter DC input 24V is in the 24V class == system 24V
passCharge controller supports 24V banksSystem voltage coherence
Victron Energy SmartSolar MPPT 100/50 supports 12/24V battery banks.
controller battery voltages [12, 24] include 24V
passString Voc stays at 47.9V at -10C - cannot reach the 100V limit at any temperatureCold-temperature string voltage
2 x Rich Solar MEGA 200 200W 12V Monocrystalline Solar Panel in series stays below the Victron Energy SmartSolar MPPT 100/50 max PV input voltage at your design low temperature. This string cannot reach 100V 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 (-10 - 25))
= 21.80V x 2 x 1.0980 = 47.9V
Controller max PV input: 100V
Crossover: string Voc reaches 100V at T = 25 + (100/43.6 - 1) x 100/-0.28 = -437C (below absolute zero - never reached)passString Vmp 36.8V has healthy margin over the 24V 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 = 24 + 5 = 29V Hot Vmp (~11% sag) = 36.8V x 0.89 = 32.8V vs hot floor 32V
passArray short-circuit current 23.20A is within the 60A limitArray current vs controller input limit
Within the Victron Energy SmartSolar MPPT 100/50 published max PV short-circuit current.
Isc_array = 11.60A x 2 parallel = 23.20A Controller max PV short-circuit current: 60A = 60A (manufacturer-specified, compared directly)
passController can pass the array's full output (31.3A of 50A rated)Array size vs controller charge output
No clipping at rated conditions.
Array = 200W x 4 panels = 800W Potential charge current = 800W / 25.6V = 31.3A Controller rated charge current: 50A
passArray 800W is within the controller's 1400W rating at 24VMax array wattage for battery voltage
Within the published maximum array wattage.
Array = 200W x 4 panels = 800W Controller max array wattage at 24V: 1400W
passVictron Energy SmartSolar MPPT 100/50 supports LiFePO4 chargingBattery chemistry support
Controller has a lithium profile or user-adjustable charge voltages.
battery chemistry = lifepo4; controller lifepo4_profile = true
passVictron Energy MultiPlus-II 24/3000/70-50 120V charger supports LiFePO4Battery chemistry support
Inverter/charger has a lithium charge profile.
battery chemistry = lifepo4; inverter charger lifepo4_profile = true
passBank BMS limit 200A comfortably covers the inverter's 93.8A drawInverter draw vs battery BMS limit
Healthy headroom at full inverter load.
Inverter draw = 2400W / 25.6V = 93.8A Bank BMS limit = 100A x 2 batteries = 200A Headroom band starts at 80% of limit = 160A
passBank BMS peak 560A covers the inverter's 214.8A surgeInverter surge vs battery peak limit
Surge loads within the bank's published peak rating.
Surge draw = 5500W / 25.6V = 214.8A Bank BMS peak = 280A x 2 batteries = 560A
pass2 in parallel is within the manufacturer limit of 4Battery parallel count
Supported parallel configuration.
2 in parallel vs manufacturer max 4
passCharge current 50A is within the bank's 200A capacityCharge current vs bank capacity
Charge rate within limits.
Controller rated charge = 50A Bank max charge = manufacturer max charge 100A x 2 = 200A
1 check not run (missing published specs)
not checkedNot checkedClosed-loop battery communications
Comms protocols for LiTime 24V 100Ah LiFePO4 are not in our data. The system will still work open-loop with manually set charge voltages.
Parts list
Wire and fuse guidance
| Segment | Continuous | Run (one way) | Copper wire | V-drop | Fuse/breaker |
|---|---|---|---|---|---|
| Array to charge controller | 23.2A | 20 ft | 10 AWG | 2.52% | 30APV-rated (gPV) fuse or DC breaker |
| Charge controller to battery bank | 50.0A | 5 ft | 6 AWG | 0.77% | 70AClass T |
| Battery bank to inverter | 93.8A | 5 ft | 1 AWG | 0.45% | 125AClass T |
Array to charge controller: show the math
Continuous current = 23.2A Design current = 23.2A x 1.25 (NEC continuous) = 29A Wire: 10 AWG copper (75C ampacity 35A); voltage drop 2.52% over 40ft 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 <= 10 AWG ampacity 35A - OK construction: PV-rated (gPV) fuse or DC breaker
Charge controller to battery bank: show the math
Continuous current = 50A Design current = 50A x 1.25 (NEC continuous) = 62.5A Wire: 6 AWG copper (75C ampacity 65A); voltage drop 0.77% over 10ft round trip at 25.6V (target <= 3%) Fuse/breaker: 70A - two criteria, both required: carry the load: fuse >= design 62.5A -> next standard size = 70A protect the wire: fuse 70A <= 6 AWG ampacity 65A - NOT satisfied, upsize the wire bank BMS continuous 200A >= fuse 70A: 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 = 93.8A Design current = 93.8A x 1.25 (NEC continuous) = 117.2A Wire: 1 AWG copper (75C ampacity 130A); voltage drop 0.45% over 10ft round trip at 25.6V (target <= 3%) Fuse/breaker: 125A - two criteria, both required: carry the load: fuse >= design 117.2A -> next standard size = 125A protect the wire: fuse 125A <= 1 AWG ampacity 130A - OK bank BMS continuous 200A >= fuse 125A: 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 |
|---|---|---|
| 10 AWG copper wire | 1 | ~45 ft total (20 ft one way, round trip + slack) - Array to charge controller |
| 30A PV-rated (gPV) fuse or DC breaker | 1 | Array to charge controller |
| 6 AWG copper wire | 1 | ~15 ft total (5 ft one way, round trip + slack) - Charge controller to battery bank |
| 70A Class T | 1 | Charge controller to battery bank - include the matching fuse holder/block |
| 1 AWG copper wire | 1 | ~15 ft total (5 ft one way, round trip + slack) - Battery bank to inverter |
| 125A 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.
About this build
This build is for people living in their van full time - digital nomads and travelers whose van is their primary residence. The system is sized for daily cycling, not weekends: laptop work all day, a fridge running around the clock, and real cooking loads. 24V is the deliberate choice over 12V here: at this inverter class the battery current at 12V would demand very thick copper and heavy-duty bus bars, while 24V halves the current for the same power.
The MultiPlus-II inverter/charger earns its place in a full-time rig because shore power stops being an afterthought: pull into a campground, plug in, and the same unit charges the bank and passes power through. The trade-off with 24V is needing a converter for the van's native 12V loads, and a slightly smaller parts ecosystem - the price of running an efficient system you cycle every single day.
Common questions
Why 24V instead of 12V for full-time vanlife?
Current. The same inverter load draws half the amps at 24V, which means smaller wire, cooler connections, and less voltage sag when cooking or running tools. 12V is simpler for small systems; daily-cycled systems at this power level are where 24V starts winning.
Can I cook on this system?
A single induction burner is within reach of this inverter class for normal cook times, but the battery has to cover the draw and the solar has to put it back. Plan heavy cooking around sun, and watch the compatibility checks when you swap components - the math is shown for exactly this reason.
Do I still need a generator?
Ideally no - that is the point of sizing solar and battery for daily cycling. But if you winter somewhere dark or run air conditioning, a small backup generator is practical planning rather than an admission of defeat.