150Ah to Wh — 1,800 Wh at 12V
150Ah stores 1,800 Wh at 12V, 3,600 Wh at 24V, and 7,200 Wh at 48V. Below: usable energy per chemistry, what it runs, and how the same energy is built from standard modules.
150Ah at 12V is 1,800 Wh — that is 1.8 kWh of nameplate energy.
Formula: Wh = Ah × V. The voltage is the nominal battery voltage, not the charging voltage.
A real LiFePO4 module of 150Ah is usually labelled 1,920 Wh, because its nominal voltage is 12.8V rather than a round 12V. Both 1,800 Wh and 1,920 Wh describe the same battery.
Result
Energy in Wh equals capacity in Ah multiplied by battery voltage. 1000 Wh equals 1 kWh.
Need a complete wiring diagram?
VoltPlan designs full electrical systems for campers, boats, and off-grid setups with automatic wire sizing, fuse placement, and battery configurations.
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 | 150 Ah | 1,800 Wh | 1.8 |
| 24 V | 150 Ah | 3,600 Wh | 3.6 |
| 48 V | 150 Ah | 7,200 Wh | 7.2 |
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 % | 1,440 Wh | 120 Ah | ~3,500 |
| AGM | 50 % | 900 Wh | 75 Ah | ~600 |
| Gel | 50 % | 900 Wh | 75 Ah | ~800 |
| Flooded lead-acid | 50 % | 900 Wh | 75 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 | 96 h |
| 12V compressor fridge (average) | 45 W | 32 h |
| Diesel heater (fan and glow plug average) | 30 W | 48 h |
| Water pump (while running) | 65 W | 22.2 h |
| Laptop plus router | 75 W | 19.2 h |
| Kettle through an inverter | 1200 W | 1.2 h |
What this size is in practice
150Ah is the single-module upgrade for full-time use: enough for a compressor fridge plus heater and pump over a cloudy day, still one battery, one fuse, one set of cables. It is also where 12V cabling starts to demand real cross-sections on the inverter side.
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 | 150 Ah | 2 x 100Ah / 12V |
| 24 V | 75 Ah | 2 x 100Ah / 12V |
| 48 V | 37.5 Ah | 2 x 100Ah / 12V |
Other capacities (Ah)
Other energy values (Wh)
FAQ
How many Wh is 150Ah?
150Ah is 1,800 Wh at 12V, 3,600 Wh at 24V, and 7,200 Wh at 48V. Multiply the amp-hours by the nominal battery voltage: Wh = Ah × V.
How much of that 1,800 Wh can I use?
On LiFePO4 at 80% depth of discharge you get 1,440 Wh (120 Ah at 12V). On AGM or gel at 50% you get 900 Wh (75 Ah). Same nameplate, very different usable energy.
How long does that run a 12V fridge?
A compressor fridge averaging 45 W runs about 32 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 1,920 Wh instead of 1,800 Wh?
Because LiFePO4 has a nominal voltage of 12.8V per 12V module, not exactly 12V. 150Ah × 12.8V = 1,920 Wh. The 12V figure of 1,800 Wh is the conservative system-voltage calculation. Both describe the same battery.
Related Calculators
Battery Bank Sizer
From daily Wh to required Ah, with chemistry-aware DoD and series/parallel layout.
Battery Runtime Calculator
How long this capacity runs your actual load list before hitting the DoD limit.
Charge Time Calculator
How long solar, alternator, or a mains charger needs to refill this bank.
Ah to Wh Guide
Why Wh is the only fair way to compare batteries, with worked camper examples.