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1280Wh to Ah — 106.7 Ah at 12V

1280 Wh is 106.7 Ah at 12V, 53.3 Ah at 24V, and 26.7 Ah at 48V. Below: usable energy per chemistry, what it runs, and which module count gets you there.

1280 Wh at 12V is 106.7 Ah of battery capacity.

Formula: Ah = Wh ÷ V. Divide by the nominal battery voltage of the bank, not by the charger voltage.

V
1V60V
Wh
0Wh50kWh

Result

Capacity (Ah)
106.7 Ah
@ 12V
In Kilowatt-Hours
1.28 kWh
Ah = Wh ÷ V = 1280 ÷ 12 = 106.7 Ah

Energy in Wh equals capacity in Ah multiplied by battery voltage. 1000 Wh equals 1 kWh.

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Design Your System
V
12V
Input
1280Wh
Output
106.7Ah
kWh
1.28kWh

At 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 voltageCapacityEnergykWh
12 V106.7 Ah1,280 Wh1.28
24 V53.3 Ah1,280 Wh1.28
48 V26.7 Ah1,280 Wh1.28

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.

ChemistryDepth of dischargeUsable energyUsable capacityCycles at that DoD
LiFePO480 %1,024 Wh85.3 Ah~3,500
AGM50 %640 Wh53.3 Ah~600
Gel50 %640 Wh53.3 Ah~800
Flooded lead-acid50 %640 Wh53.3 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.

LoadPowerRuntime
LED lighting15 W68.3 h
12V compressor fridge (average)45 W22.8 h
Diesel heater (fan and glow plug average)30 W34.1 h
Water pump (while running)65 W15.8 h
Laptop plus router75 W13.7 h
Kettle through an inverter1200 W0.9 h

What this size is in practice

1280Wh is the most common real nameplate in the 12V world: 12.8V x 100Ah LiFePO4. If a datasheet says 1280Wh and a calculator says 1200Wh, both are right - they use a different nominal voltage for the same battery.

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 voltageCapacityStandard modules
12 V106.7 Ah1 x 100Ah / 12V
24 V53.3 Ah1 x 100Ah / 12V
48 V26.7 Ah1 x 100Ah / 12V

Other energy values (Wh)

Other capacities (Ah)

FAQ

How many Ah is 1280 Wh?

1280 Wh is 106.7 Ah at 12V, 53.3 Ah at 24V, and 26.7 Ah at 48V. Divide the watt-hours by the nominal battery voltage: Ah = Wh ÷ V.

How much of that 1,280 Wh can I use?

On LiFePO4 at 80% depth of discharge you get 1,024 Wh (85.3 Ah at 12V). On AGM or gel at 50% you get 640 Wh (53.3 Ah). Same nameplate, very different usable energy.

How long does that run a 12V fridge?

A compressor fridge averaging 45 W runs about 22.8 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 1280 Wh on a real LiFePO4 module?

At the true LiFePO4 nominal voltage of 12.8V, 1280 Wh corresponds to 100 Ah. At a round 12V it is 106.7 Ah. Datasheets use 12.8V, most calculators use 12V.

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