3600Wh to Ah — 300 Ah at 12V
3600 Wh is 300 Ah at 12V, 150 Ah at 24V, and 75 Ah at 48V. Below: usable energy per chemistry, what it runs, and which module count gets you there.
3600 Wh at 12V is 300 Ah of battery capacity.
Formula: Ah = Wh ÷ V. Divide by the nominal battery voltage of the bank, not by the charger voltage.
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 | 300 Ah | 3,600 Wh | 3.6 |
| 24 V | 150 Ah | 3,600 Wh | 3.6 |
| 48 V | 75 Ah | 3,600 Wh | 3.6 |
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 % | 2,880 Wh | 240 Ah | ~3,500 |
| AGM | 50 % | 1,800 Wh | 150 Ah | ~600 |
| Gel | 50 % | 1,800 Wh | 150 Ah | ~800 |
| Flooded lead-acid | 50 % | 1,800 Wh | 150 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 | 192 h |
| 12V compressor fridge (average) | 45 W | 64 h |
| Diesel heater (fan and glow plug average) | 30 W | 96 h |
| Water pump (while running) | 65 W | 44.3 h |
| Laptop plus router | 75 W | 38.4 h |
| Kettle through an inverter | 1200 W | 2.4 h |
What this size is in practice
3600Wh is the large power-station and small off-grid class: 3.6kWh, or a 281Ah bank at 12.8V. At this energy level 12V becomes the limiting factor - the same 3.6kWh at 48V pulls a quarter of the current.
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 | 300 Ah | 3 x 100Ah / 12V |
| 24 V | 150 Ah | 3 x 100Ah / 12V |
| 48 V | 75 Ah | 3 x 100Ah / 12V |
Other energy values (Wh)
Other capacities (Ah)
FAQ
How many Ah is 3600 Wh?
3600 Wh is 300 Ah at 12V, 150 Ah at 24V, and 75 Ah at 48V. Divide the watt-hours by the nominal battery voltage: Ah = Wh ÷ V.
How much of that 3,600 Wh can I use?
On LiFePO4 at 80% depth of discharge you get 2,880 Wh (240 Ah at 12V). On AGM or gel at 50% you get 1,800 Wh (150 Ah). Same nameplate, very different usable energy.
How long does that run a 12V fridge?
A compressor fridge averaging 45 W runs about 64 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.
What capacity is 3600 Wh on a real LiFePO4 module?
At the true LiFePO4 nominal voltage of 12.8V, 3600 Wh corresponds to 281.3 Ah. At a round 12V it is 300 Ah. Datasheets use 12.8V, most calculators use 12V.
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