How many watt-hours in a 200Ah battery?
A 12 V 200Ah LiFePO4 battery (12.8 V nominal) holds 2,560 Wh (2.56 kWh), about 2,048 Wh usable at 80%. A 12 V 200Ah lead-acid bank holds 2,400 Wh, about 1,200 Wh usable at 50%.
How to work it out
- 200 Ah × 12.8 V = 2,560 Wh (2.56 kWh)
- Usable at 80% depth of discharge: 2,048 Wh (160 Ah)
Two hundred amp-hours at 12 V is where van and small RV systems start to run real appliances: a compressor fridge for days, a CPAP for a week of nights, or a microwave for a few minutes at a time.
Adjust for your project
More options: DoD
- In kWh
- 2.56 kWh
- Usable energy at your depth of discharge
- 2,048 Wh
- Usable amp-hours
- 160 Ah
Common battery sizes at the voltage above
| Battery capacity | Energy | In kWh | Usable energy at your depth of discharge |
|---|---|---|---|
| 50 | 640 Wh | 0.64 kWh | 512 Wh |
| 100 | 1,280 Wh | 1.28 kWh | 1,024 Wh |
| 200 | 2,560 Wh | 2.56 kWh | 2,048 Wh |
| 280 | 3,584 Wh | 3.58 kWh | 2,867 Wh |
| 300 | 3,840 Wh | 3.84 kWh | 3,072 Wh |
| 400 | 5,120 Wh | 5.12 kWh | 4,096 Wh |
What to know about a 200Ah bank
- One battery or two. A single 200 Ah battery and two 100 Ah batteries in parallel hold the same energy. Two batteries spread the discharge current, which matters for big inverters; Victron recommends no more than 100 A continuous from each of its 12.8 V 100 Ah batteries.
- In series it becomes 24 V. Two 100 Ah 12 V batteries in series make 24 V 100 Ah — still about 2,560 Wh, with half the current for the same load.
- Usable energy covers about a day of a modest van. Around 2,000 Wh usable runs a 12 V fridge, lights, fans, laptop and a few minutes of microwave a day — the solar load calculator tells you if yours fits.
- Charging takes real solar. Refilling about 2,000 Wh takes roughly 650 W of panels on a 4-sun-hour day; how long to charge a 200Ah battery works it through.
How long it lasts under a heavy load is on how long a 200Ah battery lasts with a 2000W inverter. The single-battery version is how many watt-hours in a 100Ah battery.
Different size? Use the full Amp-Hours to Watt-Hours Calculator.
What you’ll need
- 12 V 100 Ah LiFePO4 batteryPremium price
About 1.28 kWh rated in a box roughly the size of a group 24–31 lead-acid battery at around half the weight. Check the BMS discharge limit and whether it can charge below freezing.
See options on Amazon (opens in a new tab) - Battery monitor with shuntMid-range price
Counts amp-hours in and out, so you see true state of charge instead of guessing from voltage — which barely moves on a LiFePO4 battery until it is nearly empty.
See options on Amazon (opens in a new tab) - Smart battery charger (lithium-compatible)Mid-range price
A mains or generator-powered charger with a LiFePO4 profile tops up a bank when the sun doesn’t. Match its charge voltage to the battery data sheet.
See options on Amazon (opens in a new tab)
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Frequently asked questions
How many watt-hours is a 200Ah lead-acid battery bank?
2,400 Wh rated, about 1,200 Wh usable at 50%.
How many kWh is a 48V 200Ah battery?
10.24 kWh for a 51.2 V LiFePO4, about 8,192 Wh usable at 80%.
Other common sizes
- How many watt-hours in a 100Ah battery — 1,280 Wh (12.8 V LiFePO4) or 1,200 Wh (12 V lead-acid)
- A 48V 100Ah battery in kWh — 5.12 kWh (about 4.1 kWh usable)
Sources
- Victron Energy — Lithium Battery Smart manual, technical data (opens in a new tab) — LiFePO4 12.8 V: cycle life 2,500 at 80% DoD, 3,000 at 70%, 5,000 at 50% (to 80% of capacity); 92% round-trip efficiency; 12.8 V 100 Ah: recommended continuous discharge ≤100 A (1C), maximum 200 A; capacity about 20% lower at 0 °C; charge only between +5 °C and +50 °C.
- Trojan Battery — Technical support FAQs (opens in a new tab) — “We generally recommend a discharge of 20 to 50% of the battery’s rated capacity even though the battery is capable of being cycled to 80%”; 20-hour and 100-hour ratings; freezing points by state of charge.
- Trojan Battery — 27TMX data sheet (opens in a new tab) — Group 27 flooded: 85 Ah (5-hr), 97 Ah (10-hr), 105 Ah (20-hr), 117 Ah (100-hr); state of charge vs open-circuit voltage table; charger settings.
- Crown Battery — Deep Cycle Battery Product Specifications (effective Oct 1, 2024) (opens in a new tab) — 20-hour capacities by BCI group for flooded, AGM and lithium 12 V batteries.