200Ah to Wh — 2,400 Wh at 12V
200Ah stores 2,400 Wh at 12V, 4,800 Wh at 24V, and 9,600 Wh at 48V. Below: usable energy per chemistry, what it runs, and how the same energy is built from standard modules.
200Ah at 12V is 2,400 Wh — that is 2.4 kWh of nameplate energy.
Formula: Wh = Ah × V. The voltage is the nominal battery voltage, not the charging voltage.
A real LiFePO4 module of 200Ah is usually labelled 2,560 Wh, because its nominal voltage is 12.8V rather than a round 12V. Both 2,400 Wh and 2,560 Wh describe the same battery.
Result
Energy in Wh equals capacity in Ah multiplied by battery voltage. 1000 Wh equals 1 kWh.
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Design Your SystemAt every system voltage
The same capacity stores four times the energy at 48V that it does at 12V, and draws a quarter of the current for the same load.
| System voltage | Capacity | Energy | kWh |
|---|---|---|---|
| 12 V | 200 Ah | 2,400 Wh | 2.4 |
| 24 V | 200 Ah | 4,800 Wh | 4.8 |
| 48 V | 200 Ah | 9,600 Wh | 9.6 |
How much of it you can actually use
Nameplate energy is not usable energy. Depth of discharge caps what you may take out before you damage the battery, and it differs by chemistry.
| Chemistry | Depth of discharge | Usable energy | Usable capacity | Cycles at that DoD |
|---|---|---|---|---|
| LiFePO4 | 80 % | 1,920 Wh | 160 Ah | ~3,500 |
| AGM | 50 % | 1,200 Wh | 100 Ah | ~600 |
| Gel | 50 % | 1,200 Wh | 100 Ah | ~800 |
| Flooded lead-acid | 50 % | 1,200 Wh | 100 Ah | ~400 |
What that runs
Runtime from the usable LiFePO4 energy at 12V (80% depth of discharge), one load at a time, no inverter losses on the DC rows.
| Load | Power | Runtime |
|---|---|---|
| LED lighting | 15 W | 128 h |
| 12V compressor fridge (average) | 45 W | 42.7 h |
| Diesel heater (fan and glow plug average) | 30 W | 64 h |
| Water pump (while running) | 65 W | 29.5 h |
| Laptop plus router | 75 W | 25.6 h |
| Kettle through an inverter | 1200 W | 1.6 h |
What this size is in practice
200Ah is the target most van builds land on, reached either as two 100Ah modules in parallel or as one slimline 200Ah case. At 12V that is 2.4kWh nameplate and roughly 1.9kWh usable on LiFePO4 - about one to two days of autonomy for a typical camper.
Building the same energy from standard modules
How many standard 100Ah 12V modules add up to this energy, and what capacity that becomes at each system voltage.
| System voltage | Capacity | Standard modules |
|---|---|---|
| 12 V | 200 Ah | 2 x 100Ah / 12V |
| 24 V | 100 Ah | 2 x 100Ah / 12V |
| 48 V | 50 Ah | 2 x 100Ah / 12V |
Other capacities (Ah)
Other energy values (Wh)
FAQ
How many Wh is 200Ah?
200Ah is 2,400 Wh at 12V, 4,800 Wh at 24V, and 9,600 Wh at 48V. Multiply the amp-hours by the nominal battery voltage: Wh = Ah × V.
How much of that 2,400 Wh can I use?
On LiFePO4 at 80% depth of discharge you get 1,920 Wh (160 Ah at 12V). On AGM or gel at 50% you get 1,200 Wh (100 Ah). Same nameplate, very different usable energy.
How long does that run a 12V fridge?
A compressor fridge averaging 45 W runs about 42.7 hours on the usable LiFePO4 energy at 12V. Cycling depends on ambient temperature, so treat this as the upper bound for a well-insulated unit.
Why does the datasheet say 2,560 Wh instead of 2,400 Wh?
Because LiFePO4 has a nominal voltage of 12.8V per 12V module, not exactly 12V. 200Ah × 12.8V = 2,560 Wh. The 12V figure of 2,400 Wh is the conservative system-voltage calculation. Both describe the same battery.
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