Mobile Solar Power Made Easy, distilled

Where the book's math lands on this build

book: Mobile Solar Power Made Easy! — William Errol Prowse IV, 2018 · mobile-solarpower.com → · purchased copy archived in the private EVLife Drive folder

• Controller sizing rule: array watts ÷ bank volts = minimum controller amps. 1,350 W ÷ 24 V = 56 A → the BOM's Victron 250/60 clears it with margin. Running the bank at 24 V instead of 12 V halves the current for the same watts — the whole reason the book's big-system tier (2× controllers at 12 V) doesn't apply here.
• Max-array rule: array output must stay under the bank's max charge rate. Worst case ~53 A of charge current into a bank rated for 200 A (2× LiTime LiHeat 230 Ah) — massive headroom, no risk of over-paneling the batteries.
• Min-array rule: usable bank Wh ÷ 6 = the array that refills it in a day. 11,780 ÷ 6 = ~1,963 W (on the purchased 230 Ah bank) — our 1,350 W roof can't fully recharge a dead bank in one sunny day. The book itself defuses this: lithium doesn't need a daily full charge (only a full charge every couple of months), and this build has what no RV in the book has — a 173 kWh traction pack and shore charging behind it. Known trade, accepted consciously.
• Real-world derating: expect roughly half of nameplate as usable power. Wire loss 2–5%, controller 2–30%, battery storage 1–15%, inverter 10–15%, connectors and heat on top. The book's blunt version: a well-built 100 W panel gives you 50 usable watts; a badly built system gives you 20. Design margin, not optimism.
• Series vs parallel on a vehicle roof. The book's default for RVs is series pairs paralleled together — series for efficiency, parallel so shade on one panel doesn't kill the array. Our 3-in-series string is the max-efficiency configuration and the shade-fragile one: one shaded panel chokes all three. With the EV pack as backup that's an acceptable trade, but it's now written down as a deliberate choice, and MC4 branch connectors make a 2+1 re-wire a 20-minute experiment if boondocking under trees becomes the pattern.
• Battery isolator: keep vehicle and house electrical fully separate. The book reversed its own earlier advice — vehicle charging systems aren't built to feed a deeply discharged house bank and it can kill alternators. Moot-by-architecture on the Zevo (no alternator at all), and it matches the GM-bulletin rule already in the build plan: factory 12 V provisions for small loads only, never a house-bank bridge.
• Inverter rules: pure sine for sensitive loads, double the rating for induction start-ups, remote switch, fat cables. All already true of the Victron MultiPlus path — and the book's reminder that a 1,000 W microwave draws ~2,000 W at start-up is the same reason the inverter right-sizing lane exists in the BOM.

What the book adds — adopted into the plan

• 1. Wiring order is a hard sequence, not a suggestion. Batteries + main fuse first → charge controller wired to the bank second → panels connected last. An MPPT controller must never see panel voltage without a battery attached, and the reverse applies at teardown: pull a panel wire off the controller before touching any battery cable. Cheap insurance against a dead $435 controller.
• 2. A panel safety line. Tether the three roof panels to each other and to a rack anchor with stainless cable or marine rope, through the frame holes. If a mount ever lets go at highway speed, a 45 lb glass panel stays a panel instead of becoming a projectile. Costs almost nothing; goes into the Phase 4 roof work.
• 3. Crimping is the skill that decides system quality. Real crimp tool only — never pliers; connector gauge matched to wire; clean wire before crimping; heat shrink on everything; tug-test every termination. And the book's best diagnostic habit: feel connectors with your hand under load — any warm connector is a bad termination or an undersized wire announcing itself early.
• 4. Fuse logic: the fuse protects the wire, and only works if the wire can blow it. Appliance draw × 1.25 = fuse size; every wire fused; the main bolt-on battery fuse rated to the inverter; controller-to-battery fuse slightly above the controller rating (60 A controller → 75 A fuse — matches the BOM's MRBF positions). A big fuse on a skinny wire means the wire becomes the fuse. The Class T + MRBF plan already follows this; the ×1.25 branch-circuit rule now covers every 24 V and 12 V load added later.
• 5. A maintenance schedule the plan didn't have. Daily: glance at bank voltage (the SmartShunt makes this passive). Monthly: wiggle-test fuse block and inverter connections, inspect wire insulation for vibration chafe, clean and tug the roof panels. Every 6 months: wire-brush battery terminals, re-seat controller terminals, and clamp-meter each panel's output individually — a lazy panel means a developing fault. Adopted verbatim into the upkeep section of the build manual's future revision.

Where the book shows its age

• It's a 2018, 12 V, lead-acid-era book. Its price anchors (lithium at $900/100 Ah; $1,800/200 Ah) are 4–5× today's reality, its "most systems" tier is 400 W of solar on 12 V, and it actively discourages 24 V banks because "most appliances run on 12 volts" — solved in this build by the Orion-Tr 24→12 converter, which didn't have a cheap, reliable equivalent when the book was written.
• All the lead-acid material is skippable. Half the design chapters exist to route around lead-acid's 50% usable capacity and mandatory daily full charge. Lithium made those constraints vanish, which the book itself acknowledges every time it touches the topic.
• The product-tier recommendations are dated; the physics is not. Ignore the specific amp-tier shopping lists, keep the rules: wire to the amps, fuse to the wire, crimp like it matters, and buy the controller one size bigger than the math says so the system can grow.

Verdict: the design chapters mostly confirm what forum research already produced — worth it alone for the confidence. The install chapters are the real payload: wiring order, safety line, crimp discipline, fuse logic and the maintenance schedule are all now part of the plan. Read time well spent.