Powerhouse Off Grid
A handful of calculators to help you plan your build. Pick a tool below.
Solar Charge Calculator
Battery size, panel size and time of year — see your daily top-up and how loads affect it.
Voltage Drop & Cable Size
Check a cable size against your run, or find the smallest size that'll do the job.
Solar charge calculator
Set your battery, your panel and the time of year — we'll estimate the daily top-up in real watt-hours, not house-sized kW.
Van consumption calculator
Not sure what your gear uses? Tick what's on board and dial in how hard you run it. Tapping a selected option again clears it.
Ticked items add up to 0 Wh/day
Fills in automatically from your ticks above — drag to fine-tune, or if you've got exact figures from a device.
Daily solar top-up
With your loads running
Estimates use average UK peak sun hours by month and typical system losses (cabling, MPPT, temperature). Actual output varies with weather, exact latitude, roof orientation and battery age — treat this as a planning guide, not a guarantee.
Want a system properly sized and fitted around your van? Get in touch with Powerhouse Off Grid.
Voltage drop calculator
Set your system voltage, run length and load, then check a cable size against it — or let us tell you the smallest size that'll actually do the job properly.
As a rule of thumb: 2% or under is a great result, and up to 5% is generally treated as the borderline for non-critical circuits.
Your chosen cable
Recommended minimum
Based on standard copper conductor resistance at 20°C, calculated round-trip (out and back) for a two-core DC circuit. Real-world drop can be higher with connector losses, high ambient temperatures, or bundled/derated cable runs — this is a planning guide, not a substitute for proper cable calculation on safety-critical circuits.
Not sure which cable to buy, or need it fitted properly? Get in touch with Powerhouse Off Grid.
