Find your exact panel and battery setup for a fish finder, heater fan, underwater camera and lights — sized for real winter sun, not a summer formula. Answer 5 questions, get more time on the ice.
Built around propane fan duty cycles, frozen battery capacity loss, and how many sunless hours you're actually covering — not a generic RV formula.
This sets your baseline load — permanent houses carry more fixed electronics than a flip-over.
The heater is the #1 thing anglers size wrong. Fan draw matters far more than most calculators admit.
Check everything you'll actually plug in or charge on the ice.
This decides how much battery you need to survive without any solar input.
Winter sun hours and cold-weather battery loss both hinge on your state.
Sized for winter sun, a cold battery, and the hours your solar produces nothing.
A 100W panel produces roughly 5 amps at peak in winter. A propane furnace fan draws roughly the same 5 amps while it's running. That near-tie is why anglers on forums keep doing this math by hand — no calculator does it for them.
The fix: size your solar for electronics, lights, and charging — not the heater fan. Let propane or diesel handle heat. Solar covers everything else.
| Heater | Fan draw | Solar impact |
|---|---|---|
| Propane buddy heater | 0W | None — electronics only |
| Propane furnace + fan | 35–60W | Moderate |
| Diesel (Chinese-style) | 10–20W | Minimal ✅ |
| Electric ceramic 750W | 750W | Not solar-viable ⚠️ |
| Electric 1,500W | 1,500W | Needs 8,000W+ array ⚠️ |
The number on the spec sheet is a room-temperature number. On the ice at -10°F, it's a different battery.
| Battery type | At 32°F (0°C) | At 14°F (−10°C) | At −4°F (−20°C) |
|---|---|---|---|
| AGM | 80% | 60% | 40% |
| LiFePO4 | 85% | 72% | 55% |
| Lithium-ion (Jackery-style) | 90% | 75% | 50% |
Keep the battery inside the shanty, not in an outdoor sled box. A warm interior holds capacity — set it near the heater (not touching it), and insulate it in extreme cold. LiFePO4 is still the right chemistry for ice fishing; it just needs to run in size-up territory.
Bonus: snow reflects 80–90% of sunlight. A steep panel over ice catches direct and reflected sun — a realistic 10–15% output bump most guides never mention.
Trip length changes the battery math more than almost anything else.
Electronics, lights, heater fan. A 50Ah battery + 50W panel covers it comfortably.
14 hours of darkness with zero solar is the critical stretch. 100Ah LiFePO4 + 100W panel.
Solar recovery is critical — only ~2.5 hrs/day in Minnesota. 200W panel + 200Ah LiFePO4.
Realistic daily output from a 100W panel, by state — not a national average that doesn't apply on a frozen lake.
| State | Peak Season | Sun Hours | 100W Panel Output | Verdict |
|---|---|---|---|---|
| Minnesota | Dec–Feb | 2.5 hrs | 170 Wh | Challenging but doable |
| Wisconsin | Dec–Mar | 2.8 hrs | 190 Wh | Good for electronics |
| Michigan (U.P.) | Jan–Feb | 2.6 hrs | 175 Wh | Challenging |
| North Dakota | Dec–Feb | 2.4 hrs | 160 Wh | Hardest U.S. state |
| Iowa | Dec–Feb | 3.0 hrs | 200 Wh | Moderate |
| Illinois | Jan–Feb | 3.2 hrs | 215 Wh | Decent |
| Montana | Dec–Feb | 3.5 hrs | 235 Wh | Best western option |
| Ontario, Canada | Jan–Feb | 2.3 hrs | 155 Wh | Most challenging |
For a broader regional baseline, see the USA solar calculator, and pair your panel angle with our panel angle calculator.
A 1,500W electric heater needs roughly 18,000 Wh/day — that's an 8,000W+ array. Not practical on ice. Use propane or diesel for heat; save solar for electronics.
Winter sun sits too low. A flat panel in Minnesota captures roughly 20% of what a properly angled panel gets.
80–120W for 2–4 hours is 240–480 Wh/day — often the single biggest load on the system, and it's easy to leave off the math.
AGM loses up to 40% capacity at -20°F. A battery that tested fine at home can die mid-trip on the ice.
A cold battery underperforms no matter its rated capacity. Bring it inside, near — not against — the heat source.
Both work — the right one depends on how often you're on the ice and what kind of shanty you run.
Best for: day trips and flip-over shanties. All-in-one, zero wiring, easy to move between spots.
Best for: permanent fish houses and multi-day trips. A 100W panel + 100Ah LiFePO4 runs roughly $350 total — more cost-effective for regular use.
Five questions, one calculator built specifically for the ice — not a van or cabin formula stretched to fit.
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