Size loads, batteries, solar, and wire — for RVs, vans, tiny homes, off-grid cabins, boats, food trucks, telecom sites, farm pumps, and almost anything else that runs on DC or hybrid power. Free tier. Real math. Permit-ready PDFs.
Free forever. No credit card required.
Engineering-grade design documentation for your system — single-line schematic, demand-factor load schedule, conductor + OCPD schedules, 24-hour load profile, full code citations. Ready for installer use and as the design package a P.Eng / PE reviews and stamps where required. Pick your jurisdiction:
Workflow
Search our database of 150+ appliances or add custom loads. Set wattage, quantity, and hours of use.
Get instant recommendations for battery capacity, solar panels, and charge controllers based on your actual usage.
Download a professional PDF report with your complete system design, or share it with your installer.
Capabilities
The calculation engine started with ABYC E-11 because marine is the toughest spec around. The same engine now powers RV, tiny home, cabin, food truck, telecom, and every other niche PowerLab supports.
Pull from our database of 150+ appliances or add custom loads. See a real-time power budget in daily Wh, Ah, and peak watts.
Compare AGM, LiFePO4, Gel, and Flooded. Get bank configuration, cost estimates, and weight.
Panel count, charge controller sizing, and MPPT vs PWM recommendations based on your location.
Compare different setups side by side. Toggle loads, change chemistry, adjust solar — see the impact instantly.
ABYC E-11 compliant wire gauge recommendations with voltage drop calculations and fuse sizing.
Professional system reports with complete load analysis, sizing recommendations, and bill of materials.
25+
systems designed in PowerLab to date
Methodology
Every PowerLab recommendation is traceable to a published standard. No estimates, no rules of thumb, no guesswork.
Voltage-drop limits, ampacity ratings, and fuse sizing calculated per the ABYC E-11 standard for AC & DC electrical systems on boats — the same standard marine surveyors reference.
Battery bank capacity respects the safe depth-of-discharge for each chemistry — roughly 50% for AGM/Gel/Flooded, 80% for LiFePO4 — plus your chosen days of autonomy.
Solar arrays are sized against local peak sun hours with proper MPPT vs PWM charge-controller efficiency derating — not rules-of-thumb like “just buy 400W.”
Daily Load
2,847 Wh
Battery Bank
400 Ah
Solar Array
3.2 kW
Est. Cost
$8,500
Field log
Browse power systems that PowerLab users are actually running today — across every niche PowerLab supports.
Basic coastal cruising setup with essential navigation, lighting, and comfort appliances.
Daily
1,735 Wh
Battery
400 Ah
Solar
600 W
View full design →
Trans-Atlantic-ready 40-footer running a 24V house bank with 600Ah LiFePO4. Staged in Lagos, Portugal preparing for an Atlantic crossing. Heavy watermaker + Starlink + AIS + autopilot 24/7.
Daily
6,811 Wh
Battery
1600 Ah
Solar
2000 W
View full design →
Classic Westsail 32 kept on a mooring in Sausalito Bay. Three 100Ah AGMs feeding minimal liveaboard loads year-round. Deliberately simple — no watermaker, propane cooking, minimal electronics. 3 days autonomy sized for Bay Area fog stretches.
Daily
2,266 Wh
Battery
1200 Ah
Solar
800 W
View full design →
Weekend cruiser out of Annapolis. 200Ah LiFePO4 bank replacing the original flooded bank. Anchors out 2 nights most weekends, club dock midweek. 300W rooftop solar + alternator handles weekend turnaround.
Daily
1,634 Wh
Battery
400 Ah
Solar
600 W
View full design →
28-foot center console with dual 100Ah AGM house bank. Day trips only — runs a genset for A/C at the dock. Heavy pull from radar + chartplotter + bait aerator when trolling all day.
Daily
1,194 Wh
Battery
200 Ah
Solar
400 W
View full design →
Plans
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Mid-market fleets: charter, rental, marina, yacht mgmt
from — $1,500 base + $99/vessel · 3–50 vessels
| Feature | Free | Pro |
|---|---|---|
| Load calculator (150+ appliances) | ||
| Battery & solar sizing | ||
| Shareable design link | ||
| Projects | 3 | Unlimited |
| Scenario comparison | — | |
| ABYC E-11 wire sizing | — | |
| Component matcher & BOM export | — | |
| Professional PDF reports | — | |
| Installed-component & warranty tracking | — | |
| Public Pro profile at /p/<slug> | — | |
| REST API + per-user keys | — | |
| Priority email support | — |
Permit-ready PDFs are a separate $59 CAD one-off per project — no subscription required.
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