How do you convert Wh to Ah?
Divide watt-hours by the battery's nominal voltage: Ah = Wh ÷ V. 2,000 Wh at 12.8 V is about 156 Ah.
Battery energy
Wh to Ah
To turn an energy target in watt-hours into the amp-hours you'd order, divide by the pack voltage — 2,000 Wh is 156 Ah on a 12.8 V LiFePO₄ pack but only 42 Ah on 48 V. Set your chemistry or voltage below.
Formula
Ah = Wh ÷ V (amp-hours = watt-hours ÷ pack voltage)
Wh
=
Charge
312.5 Ah
V
Tip: use the nominal voltage of one cell for a single cell, or the whole pack voltage for a battery bank.
1000 Wh ÷ 3.2 V = 312.5 Ah
Reference table
Change the voltage in the calculator aboveWatt-hours to Amp-hours at 3.2 V
| Watt-hours (Wh) | Amp-hours (Ah) |
|---|---|
| 1 Wh | 0.3125 Ah |
| 5 Wh | 1.5625 Ah |
| 10 Wh | 3.125 Ah |
| 50 Wh | 15.625 Ah |
| 100 Wh | 31.25 Ah |
| 500 Wh | 156.25 Ah |
| 1000 Wh | 312.5 Ah |
Why it matters
Why this conversion needs a voltage
Batteries are usually sold in amp-hours, but you plan loads in watt-hours — so converting Wh back to Ah at your real voltage is how you actually spec what to buy. Higher-voltage packs need far fewer amp-hours for the same energy, which is why 48 V systems use thinner cabling.
Real-world use
Where you'll use it
Turn a daily Wh energy budget into the Ah capacity you need to order.
Compare how many amp-hours a target energy needs at 12 V vs 24 V vs 48 V.
Right-size a lithium replacement for a lead-acid bank by matching usable Wh.
Plan series/parallel packs by working back from energy to amp-hours per string.
FAQ
Common questions about wh to ah
Why do higher-voltage packs need fewer amp-hours?
Because Ah = Wh ÷ V. For the same energy, raising the voltage lowers the amp-hours (and the current), which is why 48 V systems use smaller cables than 12 V ones.
Which voltage do I enter?
Use your pack's nominal voltage — tap a chemistry preset above (LiFePO₄, Li-ion, lead-acid, LTO, NiMH) or type the exact pack voltage if you know it.
Should I add margin for usable capacity?
Yes. Lead-acid is usually limited to about 50% depth of discharge and lithium to roughly 80–90%, so size the amp-hours above your raw requirement accordingly.
Related routes
Keep going
Unitly.fyi · results update live — set your own voltage or battery chemistry above.