Sprinter van
12 V · 400 W solar
// By MarinePowerLab — off-grid · RV · marine
The compliance-document engine
for people who pull permits.
Deterministic. Clause-cited. Inspector-formatted.
Send us your panels, batteries, and loads. Our MarinePowerLab team drafts the code-cited permit set — wire sizing, voltage drop, overcurrent, one-line diagram — against NEC and ABYC, in ~5 business days. Rather DIY? The same engine is free to use below.
Or DIY free — full calculator · 3 projects · watermarked PDF · no card · sample report
NEC 310.16Ch.9 Tbl 8NEC 240.6ABYC E-11
drawing-sheet · one-linechecked
Sprinter van · 12 V · 400 W
Rev A · NEC 690 / 706 / 710
Rev A · NEC 690 / 706 / 710
9-page
Permit-ready PDF
2 codes
NEC + ABYC today
100%
Deterministic — same in, same out
~$5,000
What a stamped design costs
process
Parts list to permit-ready, in three moves.
01Design
Design
Drag components onto the canvas — or describe the system and let AI place them. Every wire is sized the moment you connect it.
panelmpptbatteryfuseinverter
02Check
Check
Run the NEC / ABYC compliance pass. Every violation is flagged with the exact clause and the fix — not a vague warning.
✓ Overcurrent OK — NEC 240.6
!Fuse > 7" from battery — ABYC E-11
03Export
Export
Generate the insurance-grade PDF — one-line diagram, BOM with SKUs, full calculation appendix, and a plain-English AI summary.
coverage
One engine. Van, cabin, or hull.
The same deterministic calculator drives DC van builds, 48 V off-grid cabins, and ABYC marine refits. These are live templates — open any one and start from a working design.
NEC 690 / 706 / 710
Off-grid cabin
48 V · 2 kW solar
Sailboat refit
12 V marine
the deliverable
What lands in the PDF.
- 01Cover + project header
- 02Executive summary
- 03One-line schematic
- 04Bill of materials (SKUs)
- 05Wire-sizing calculations
- 06Voltage-drop analysis
- 07Overcurrent protection
- 08Compliance checklist
- 09References + AI summary
Bill of materials
| Qty | Component | Spec | Basis |
|---|---|---|---|
| 1 | Solar array | 400 W · Voc 49 · Isc 11 | NEC 690.8 |
| 1 | MPPT controller | 50 A | 690.8(B) |
| 1 | LiFePO₄ bank | 200 Ah · 12 V | NEC 706 |
| 1 | Class-T fuse | 250 A | NEC 240.6 |
| 1 | Inverter | 2000 W / 4000 W surge | NEC 690.8 |
Wire runs — sized to ampacityall ✓
| Run | Length | Current | Basis |
|---|---|---|---|
| Battery → Fuse | 1 ft | 180 A | NEC 310.16 |
| MPPT → Battery | 3 ft | 50 A | NEC 310.16 |
| Solar → MPPT | 8 ft | 11 A | NEC 690.8 |
Values from the Sprinter-van template · illustrative of the output
why it holds up
Not just another chatbot answer.
Deterministic & cited
The same inputs always produce the same answer — each one traceable to NEC 310.16, Ch.9 Table 8, 240.6, or ABYC E-11. Auditable, not a guess.
A document people accept
Inspectors and insurers get a formatted report with a one-line diagram and sign-off blocks — not a chat transcript they have to trust.
Honest by design
It is not a P.Eng stamp, and it says so on every page. Built to aid your installer, surveyor, and underwriter — never to impersonate them.
pricing
Done-for-you, or do-it-yourself.
Hand us the build and we draft the permit set, or design it yourself and export it. Either way it is a rounding error next to a ~$5,000 engineer-stamped design.
Most popular
Done-For-You
$499one-time
We draft your code-cited permit set — NEC or ABYC — in ~5 business days · 7-day money-back
Start an orderCompliance Pack
$99one-time
One unwatermarked 9-page permit-ready PDF · 30-day money-back
Buy a single proofAlso: Free · Business $79/mo — full table on pricing
common questions
Is this a P.Eng / PE stamp?+
No — it is design documentation generated from your input and published codes. It does not replace a stamp where one is required. Verify with a licensed professional before installation.
What codes are supported?+
NEC 690 / 706 / 710 and ABYC E-11 today. ISO 13297 and AS/NZS 3001 are on the roadmap.
Can I use it for insurance or an AHJ?+
It produces the kind of documentation that aids their review. Final approval rests with the AHJ or carrier.
Send the build. We'll draft the proof.
Photos + a parts list in, a code-cited permit set out in ~5 business days. Or start free with the calculator.