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RV & Trailer Solar Calculator

Free Canadian RV solar calculator: enter daily Wh, peak sun hours and battery type — get panel wattage, battery Ah, MPPT controller and inverter size for trailers, motorhomes and camper vans.

RV Solar Calculator

Battery capacity
733 Ah
Recommended solar wattage
800 W
MPPT controller size
80 A
Inverter rating
1,000 W

What this calculator does

This Canadian RV solar calculator sizes a complete 12 V or 24 V off-grid system for any recreational vehicle — travel trailer, fifth-wheel, motorhome, Class B van or skoolie conversion. Enter your daily energy use in watt-hours, peak sun hours, battery chemistry preference and peak 120 V load, and it returns four numbers: battery bank capacity in Ah, solar panel wattage, MPPT controller amp rating, and inverter wattage.

Every result includes the CSA C22.1 Section 64 125% continuous-load factor on the charge controller — the multiplier any Canadian electrical contractor applies when certifying an installation.

The four numbers every RV solar build needs

A complete RV solar system is four components matched: panels, MPPT charge controller, battery bank, and inverter. Undersize any one and the whole rig fails: too few panels and the bank never recharges; too small a battery and you wake up with a flat system; an undersized controller throttles the array; an inverter that can’t handle peak loads trips offline mid-microwave.

1. Battery capacity (Ah)

Battery Ah = (Daily Wh × Days of autonomy) ÷ (Battery V × Depth of Discharge)

For a 2,200 Wh daily load on a 12 V AGM bank at 50% DoD with 2 days of cloudy reserve: 2200 × 2 ÷ (12 × 0.50) = 733 Ah. That’s four 220 Ah Surrette/Rolls or Trojan T-105 6 V batteries in series-parallel.

LiFePO4 changes the math. Same 2,200 Wh, same 2 days, DoD at 80%: 2200 × 2 ÷ (12 × 0.80) = 458 Ah. Two Battle Born 270 Ah, three Renogy 200 Ah, or one Lion Energy UT-1300 / Big Battery Husky 600 Ah module cover it. Lithium weighs about 14 kg per 100 Ah versus 30 kg for AGM, charges in a third of the time, and survives 3,000–6,000 cycles versus 400–800 for lead-acid. CanmetENERGY’s stand-alone PV guidance puts LiFePO4 levelized cost per cycle below AGM.

2. Solar panel wattage (W)

Panel W = Daily Wh ÷ (Peak Sun Hours × System Efficiency)

For 2,200 Wh per day at 3.8 PSH (Canadian summer average): 2200 ÷ (3.8 × 0.80) = 724 W → round up to 800 W. NRCan PSH data shows Vancouver at 3.5 summer / 1.3 winter, Calgary 4.2 / 1.6, Ottawa 4.0 / 1.7, Halifax 3.8 / 1.6. Size for the lowest month you’ll be camping; high Arctic boondocking in June (PSH 6+) is different from Lake Ontario shoulder-season in October (PSH 1.8).

3. MPPT charge controller (A)

Controller A = Panel W ÷ Battery V × 1.25

The 1.25 factor reflects CSA C22.1 Section 8 (continuous loads) — protective devices and controllers must be rated above 100% of the design current. A 800 W array on 12 V needs 800 ÷ 12 × 1.25 = 83.3 A → 100 A MPPT, or split across two 60 A units (Victron 100/50 × 2, Outback FM60 × 2). At 24 V it halves: 800 ÷ 24 × 1.25 = 41.7 A → 50 A.

Always check the controller’s PV input voltage limit against the array’s open-circuit voltage at the coldest temperature you’ll camp at. Canadian cold mornings can push panel Voc up 15–20% above STC — important when running 3 panels in series on a 100 V controller.

4. Inverter (W)

Inverter W = Peak simultaneous 120 V load × 1.25

A 1,000 W microwave running with an 800 W kettle and a 30 W phone charger needs 1,830 × 1.25 = 2,288 W → 3,000 W pure-sine inverter (Victron Phoenix 3000, Aims PWRIC3000W, or Magnum MS2000). For laptop, TV and small appliances, 1,500 W is enough. Pure-sine only.

Sample sizing for common Canadian RV setups

Weekend travel trailer (1,800 Wh/day, 12 V, AGM) — A retired couple in a Forest River Wildwood running LED lighting, 12 V compressor fridge, vent fan and devices. 1,800 ÷ (3.8 × 0.80) = 592 W → 600 W array (two 300 W panels). Battery: 1,800 × 2 ÷ (12 × 0.50) = 600 Ah → four Surrette S-460 in series-parallel. Controller: 600 ÷ 12 × 1.25 = 62.5 A → 80 A MPPT. Inverter: 1,500 W. HomeStars-listed installer pricing in 2025–2026: C$3,800–5,400 DIY parts, C$6,400–9,000 dealer-fitted.

Full-time fifth-wheel (4,500 Wh/day, 12 V, LiFePO4) — A family in a Heartland Bighorn with residential fridge, satellite TV, induction hob and instant pot. 4,500 ÷ (3.8 × 0.80) = 1,480 W → 1,600 W array. Battery: 4,500 × 2 ÷ (12 × 0.80) = 938 Ah LiFePO4 — four Battle Born 270 Ah heated or six Renogy 200 Ah heated. Controller: 1,600 ÷ 12 × 1.25 = 167 A — split across two 80 A MPPTs. Inverter: 3,000 W pure-sine. Installed DIY: C$10,500–14,800.

Class B Sprinter conversion (3,200 Wh/day, 24 V, LiFePO4) — A nomad in a Sprinter 144 conversion with LED lighting, Dometic CFX, Maxxair fan, induction cooktop and laptop docks. 3,200 ÷ (3.8 × 0.80) = 1,053 W → 1,200 W array. Battery: 3,200 × 2 ÷ (24 × 0.80) = 333 Ah at 24 V (about 250 Ah usable). Controller: 1,200 ÷ 24 × 1.25 = 62.5 A → 80 A MPPT. Inverter: 2,000 W pure-sine. Conversion specialists in Vancouver, Calgary and Montreal: C$8,200–12,500.

Canadian wiring and code references

Canadian RV solar must follow:

  • CSA C22.1 (Canadian Electrical Code) Section 64 — Solar Photovoltaic Systems. Conductor sizing, string fusing, equipment grounding.
  • CSA C22.1 Section 8 — continuous-load 125% factor on conductors and protective devices.
  • CSA C22.2 No. 107.1 — Power conversion equipment (inverters, MPPT controllers).
  • CAN/ULC-S801 — Standard for electric utility workplace electrical safety (where AC bus modifications cross into permanently installed work).
  • Provincial Electrical Code amendments — BC, Alberta, Ontario, Quebec each add jurisdictional requirements above CSA C22.1.

Use the solar panel wire size calculator for AWG sizing per CSA C22.1 Table 2 ampacity, and the solar panel grounding calculator to size the equipment grounding conductor per Section 64.

Common Canadian RV solar mistakes

  • Charging cold LiFePO4 batteries. Below 0 °C lithium plates and the capacity drops permanently. Use heated modules or switch to AGM for winter.
  • Sizing for July (4.5 PSH) when you’ll be parked at Lake Louise in October (1.8 PSH). Size for the lowest PSH month you actually camp in.
  • Wiring panels in parallel only on long roof runs. Two 12 V panels in parallel produce 12 V × 16 A — that needs 6 AWG over a 4 m run. Series them at 24 V to draw 8 A and run cleanly on 10 AWG.
  • Skipping the CSA 125% factor. A 60 A MPPT exactly matched to a 720 W 12 V array (60 A nominal) thermally cycles and fails within months.
  • Mixing AGM and LiFePO4 in the same bank. They have incompatible bulk/absorb/float voltages and will damage each other.

Sources

Frequently asked questions

How many watts of solar do I need on my Canadian RV?
A typical Canadian travel trailer with LED lighting, a 12 V compressor fridge, a Maxxair vent fan and device charging uses 1,800–2,400 Wh per day. At the Canadian summer average of 3.8–4.2 peak sun hours, that needs 580–790 W of panels with an 80% efficiency factor — most owners run 600–800 W rooftop arrays. Full-timers with a residential fridge, microwave and inverter draw 4,000–7,000 Wh and need 1,400–2,200 W. NRCan PSH data shows southern BC and Alberta averaging 4.0–4.5 PSH summer and 1.5–2.0 winter — size for the lowest month you'll camp.
What size battery for Canadian RV solar?
Battery capacity in Ah equals daily Wh times days of autonomy, divided by battery voltage times depth-of-discharge. For 2,200 Wh daily on a 12 V AGM bank at 50% DoD with 2 days reserve: 2200 × 2 ÷ (12 × 0.50) = 733 Ah. Switching to LiFePO4 at 80% DoD: 458 Ah. Most Canadian RV builds now use Renogy 200 Ah, Battle Born 100 Ah or BCI lithium modules rather than Surrette/Rolls AGM banks — the 30 kg-per-100 Ah weight saving matters for trailer GVWR limits. Note: lithium tolerates Canadian winters down to 0 °C charging — below that, install a heated module (Battle Born GC2, EcoFlow LFP heated).
MPPT or PWM for Canadian RV solar?
MPPT for any array above 200 W. Canadian RV solar panels are typically 60-cell or 72-cell monocrystalline that produce 18–24 V open-circuit, well above the 12 V battery target. A PWM controller wastes 25–30% of array output. An MPPT (Victron SmartSolar 100/30, Renogy Rover 40, Outback FlexMax 60) recovers it at 96–97% efficiency. Price gap: C$150–280 for a 30 A MPPT versus C$50–100 for PWM at Canadian Tire, Princess Auto or Solar Solutions.
Will RV solar work in Canadian winters?
Output drops 70–85% in Canadian winters at the latitudes of Calgary, Saskatoon and Winnipeg — December PSH falls to 0.8–1.5 hour from a summer peak of 5.0. Snow accumulation blocks production until cleared. Tilt-up panel brackets help shed snow and steepen the winter angle for shoulder-season camping. Most snowbird Canadians who tour year-round split their year: solar handles April–October in Canada, then USA south or Mexico from November–March where PSH stays above 4.0.
Do I need an electrical contractor for Canadian RV solar?
DC-side solar work (panels, MPPT controller, battery bank, DC distribution) is generally exempt from provincial electrical permit requirements when in an RV registered under provincial Motor Vehicles Act. The AC side is different — any modification to the inverter input/output, 120 V wiring, breaker panel, or shore-power cord requires a licensed electrician in BC, Alberta, Ontario and Quebec. Cross-reference your provincial Electrical Code amendments to CSA C22.1. CanmetENERGY's guidance is to follow CSA C22.1 Section 64 for PV installations regardless of permit status.
What about cold-weather charging with LiFePO4?
LiFePO4 batteries can discharge below 0 °C but cannot accept charge — charging a frozen cell causes lithium plating and permanent capacity loss. Three workarounds: 1) Install heated-module batteries (Battle Born GC2 heated, Lion Energy UT-1300 heated, EcoFlow LFP) that draw a few watts to keep cells above 5 °C. 2) Use the MPPT's load output to drive a 50 W silicone heating pad under the bank, controlled by a 0 °C thermostat. 3) Switch to AGM for winter trips — it accepts charge down to -20 °C, just at reduced capacity.

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