Ah to Wh Conversion Chart (2026): 100Ah = 1,200Wh at 12V, 2,400Wh at 24V, 4,800Wh at 48V
Full Ah to Wh table for 50–400Ah at 12V, 24V, and 48V — plus device runtimes, usable energy by chemistry (LiFePO4 vs AGM), reverse Wh-to-Ah chart, and camper sizing examples. Free calculator for any value.
To convert amp-hours to watt-hours, multiply by the battery voltage: Wh = Ah × V. A 100Ah battery at 12V stores 1,200Wh (1.2 kWh). At 24V the same 100Ah stores 2,400Wh. At 48V it stores 4,800Wh. For any value, the free Ah to Wh converter does the math in one step.
Ah to Wh Conversion Table: 12V, 24V, and 48V
| Capacity | @ 12V | @ 24V | @ 48V |
|---|---|---|---|
| 50 Ah | 600 Wh (0.6 kWh) | 1,200 Wh (1.2 kWh) | 2,400 Wh (2.4 kWh) |
| 75 Ah | 900 Wh (0.9 kWh) | 1,800 Wh (1.8 kWh) | 3,600 Wh (3.6 kWh) |
| 100 Ah | 1,200 Wh (1.2 kWh) | 2,400 Wh (2.4 kWh) | 4,800 Wh (4.8 kWh) |
| 150 Ah | 1,800 Wh (1.8 kWh) | 3,600 Wh (3.6 kWh) | 7,200 Wh (7.2 kWh) |
| 200 Ah | 2,400 Wh (2.4 kWh) | 4,800 Wh (4.8 kWh) | 9,600 Wh (9.6 kWh) |
| 230 Ah | 2,760 Wh (2.76 kWh) | 5,520 Wh (5.52 kWh) | 11,040 Wh (11.0 kWh) |
| 280 Ah | 3,360 Wh (3.36 kWh) | 6,720 Wh (6.72 kWh) | 13,440 Wh (13.4 kWh) |
| 300 Ah | 3,600 Wh (3.6 kWh) | 7,200 Wh (7.2 kWh) | 14,400 Wh (14.4 kWh) |
| 400 Ah | 4,800 Wh (4.8 kWh) | 9,600 Wh (9.6 kWh) | 19,200 Wh (19.2 kWh) |
The formula works in both directions. To go from Wh back to Ah, divide by voltage: Ah = Wh ÷ V.
Wh to Ah Reverse Conversion Table
| Energy (Wh / kWh) | Ah at 12V | Ah at 24V | Ah at 48V |
|---|---|---|---|
| 600 Wh (0.6 kWh) | 50 Ah | 25 Ah | 12.5 Ah |
| 1,200 Wh (1.2 kWh) | 100 Ah | 50 Ah | 25 Ah |
| 2,400 Wh (2.4 kWh) | 200 Ah | 100 Ah | 50 Ah |
| 3,000 Wh (3.0 kWh) | 250 Ah | 125 Ah | 62.5 Ah |
| 3,600 Wh (3.6 kWh) | 300 Ah | 150 Ah | 75 Ah |
| 4,800 Wh (4.8 kWh) | 400 Ah | 200 Ah | 100 Ah |
| 5,000 Wh (5.0 kWh) | 417 Ah | 208 Ah | 104 Ah |
| 10,000 Wh (10 kWh) | 833 Ah | 417 Ah | 208 Ah |
Use the reverse table when you know how much daily energy you need and want to work out what size battery bank to buy.
Usable Wh by Battery Chemistry
The Wh figure from the formula above is the total stored energy — not what you can actually draw before damaging the battery.
| Chemistry | Depth of Discharge | Usable % | 100Ah 12V (1,200Wh total) |
|---|---|---|---|
| LiFePO4 | Up to 80–100% | ~90% typical | ~1,080 Wh usable |
| AGM | 50% max to preserve life | ~50% | ~600 Wh usable |
| Flooded lead-acid | 50% max | ~50% | ~600 Wh usable |
Practical conclusion: a 100Ah LiFePO4 delivers roughly twice the usable energy of a 100Ah AGM, even though the nameplate Ah is identical. When comparing batteries across chemistries, always compare usable Wh, not nameplate Ah.
How Long Will Your Battery Last? Day-Autonomy Table
Use this table to check how many days a given battery bank lasts at two typical camper consumption levels: light use (1,000 Wh/day) and heavy use (2,000 Wh/day). Values assume 80% usable depth of discharge (LiFePO4).
| Battery Bank | Usable Wh | Days at 1,000 Wh/day | Days at 2,000 Wh/day |
|---|---|---|---|
| 100 Ah @ 12V | ~960 Wh | 0.96 days | 0.5 days |
| 200 Ah @ 12V | ~1,920 Wh | 1.9 days | 0.96 days |
| 100 Ah @ 24V | ~1,920 Wh | 1.9 days | 0.96 days |
| 300 Ah @ 12V | ~2,880 Wh | 2.9 days | 1.4 days |
| 200 Ah @ 24V | ~3,840 Wh | 3.8 days | 1.9 days |
| 400 Ah @ 12V | ~3,840 Wh | 3.8 days | 1.9 days |
| 200 Ah @ 48V | ~7,680 Wh | 7.7 days | 3.8 days |
Notice that 200Ah at 24V gives the same usable Wh as 400Ah at 12V — at a fraction of the weight and cable cost. Higher-voltage systems win on efficiency when the bank grows past a certain size.
Device Runtime at 100Ah / 12V (960Wh Usable)
| Device | Typical Power Draw | Runtime on 100Ah 12V |
|---|---|---|
| Compressor fridge (12V) | 40–55 W average | 17–24 hours |
| LED interior lighting | 20 W | 48 hours |
| Diesel / propane heater fan | 20 W | 48 hours |
| Maxxair vent fan (medium) | 20 W | 48 hours |
| Phone + laptop charging | 60–80 W | 12–16 hours |
| 1000 W inverter at half load | 500 W | ~1.9 hours |
| Water pump (intermittent) | 60 W, 15 min/day | ~100 days of pump use |
These are averages — your actual runtime depends on ambient temperature, the specific model, and how frequently loads cycle. Use the battery runtime calculator with your exact wattage and hours-per-day for a circuit-level result.
Worked Sizing Example: Planning a Camper Battery Bank
Goal: 2 days of autonomy for a camper using a compressor fridge (50W), LED lighting (20W for 5h), a vent fan (20W for 6h), and phone+laptop charging (60W for 2h).
- Daily load: (50 × 24) + (20 × 5) + (20 × 6) + (60 × 2) = 1,200 + 100 + 120 + 120 = 1,540 Wh/day
- 2-day buffer: 1,540 × 2 = 3,080 Wh
- Add 20% reserve: 3,080 ÷ 0.80 = 3,850 Wh (to preserve LiFePO4 DoD)
From the reverse conversion table above: 3,850 Wh at 12V needs ~320 Ah, or at 24V needs ~160 Ah.
Practical choices: 2 × 200 Ah at 12V (4,800 Wh, 3.8 days), or 2 × 100 Ah at 24V (same energy, half the current on every cable). The battery bank sizer walks through this calculation with chemistry-specific DoD and series/parallel layout.
Frequently Asked Questions
How many watt-hours is a 100Ah battery?
A 100Ah battery stores 1,200Wh (1.2 kWh) at 12V, 2,400Wh (2.4 kWh) at 24V, and 4,800Wh (4.8 kWh) at 48V. The Wh depends entirely on voltage — the Ah rating alone does not describe stored energy.
How many watt-hours is a 200Ah battery?
A 200Ah battery stores 2,400Wh (2.4 kWh) at 12V, 4,800Wh (4.8 kWh) at 24V, and 9,600Wh (9.6 kWh) at 48V. At a typical camper consumption of 1,500–2,000 Wh/day (with 80% DoD), that is roughly 1 to 1.5 days of autonomy at 12V or 2 to 3 days at 24V.
How many watt-hours is a 300Ah 12V battery?
A 300Ah 12V battery stores 3,600Wh (3.6 kWh) total. With 80% depth of discharge on LiFePO4, you get roughly 2,880 Wh usable — about 1.5 to 2.5 days for a typical camper depending on load.
How many kWh is a 100Ah 12V battery?
1.2 kWh (1,200Wh ÷ 1,000 = 1.2). A 100Ah 24V battery stores 2.4 kWh. A 100Ah 48V battery stores 4.8 kWh. The kWh is simply the Wh figure divided by 1,000.
Is a 100Ah 12V battery the same energy as a 50Ah 24V battery?
Yes — both store 1,200Wh. The energy in watt-hours is what matters for comparing batteries, not Ah alone. A 50Ah 24V LiFePO4 and a 100Ah 12V LiFePO4 can run the same loads for the same duration.
How do I convert Wh back to Ah?
Divide watt-hours by the battery voltage: Ah = Wh ÷ V. A 3,600Wh bank at 12V is 300Ah. The same 3,600Wh at 24V is 150Ah. The reverse conversion table above covers the most common sizes.
How many Ah do I need for 2 kWh at 12V?
2 kWh = 2,000Wh. At 12V: 2,000 ÷ 12 = ~167 Ah. In practice you would round up to 200Ah to stay within 80% DoD on LiFePO4. The battery bank sizer accounts for DoD, chemistry, and autonomy days in one step.
How does temperature affect Ah and Wh?
Cold reduces usable capacity. At 0°C most LiFePO4 cells deliver around 85% of rated capacity; at -10°C roughly 70%. The Wh figures in this article are at room temperature (20°C). For winter camping, either derate your bank by 15–30% or use a battery with a built-in low-temperature charging cutoff.
How many solar panels do I need to recharge a 200Ah 12V battery in a day?
A 200Ah 12V battery stores 2,400Wh. To recharge it from 80% DoD in 6 peak sun hours, you need roughly 2,400 × 0.80 ÷ 6 ÷ 0.85 ≈ 375W of solar panels (accounting for ~15% MPPT and wiring losses). In practice: two 200W panels give comfortable headroom for overcast days and shading losses.
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