How many kWh is a 48V 100Ah battery?
A 48V 100Ah LiFePO4 battery is 51.2 V nominal, so it holds 5,120 Wh — 5.12 kWh — with about 4,096 Wh usable at 80% depth of discharge.
How to work it out
- 100 Ah × 51.2 V = 5,120 Wh (5.12 kWh)
- Usable at 80% depth of discharge: 4,096 Wh (80 Ah)
Forty-eight-volt server-rack and wall batteries are the usual building block for home backup and whole-cabin systems. Crown’s 48 V lithium data sheet, for example, lists a 51.2 V 105 Ah module — sixteen 3.2 V cells in series.
Adjust for your project
More options: DoD
- In kWh
- 5.12 kWh
- Usable energy at your depth of discharge
- 4,096 Wh
- Usable amp-hours
- 80 Ah
Common battery sizes at the voltage above
| Battery capacity | Energy | In kWh | Usable energy at your depth of discharge |
|---|---|---|---|
| 50 | 2,560 Wh | 2.56 kWh | 2,048 Wh |
| 100 | 5,120 Wh | 5.12 kWh | 4,096 Wh |
| 200 | 10,240 Wh | 10.24 kWh | 8,192 Wh |
| 280 | 14,336 Wh | 14.34 kWh | 11,469 Wh |
| 300 | 15,360 Wh | 15.36 kWh | 12,288 Wh |
| 400 | 20,480 Wh | 20.48 kWh | 16,384 Wh |
What to know about 48 V batteries
- Four times the energy of a 12 V 100 Ah. Same amp-hours, four times the voltage — about 5 kWh instead of 1.28 kWh.
- A quarter of the current. A 3,000 W inverter pulls roughly 280 A from 12 V but about 70 A from 48 V, which is the main reason home systems are built at 48 V.
- Labels vary: 48 V or 51.2 V. Lithium packs are often sold as “48 V” but are 51.2 V nominal. Use the nominal figure for watt-hours; a lead-acid 48 V bank really is 48 V.
- Stacking. Several modules in parallel add kWh: three 5.12 kWh modules make about 15.4 kWh. The home backup battery calculator sizes the number for an outage.
For a house in an outage, start with how many kWh it takes to power a house for a day. For a smaller 12 V system, how many watt-hours in a 100Ah battery shows the same arithmetic.
Different size? Use the full Amp-Hours to Watt-Hours Calculator.
What you’ll need
- Battery monitor with shuntMid-range price
Counts amp-hours in and out, so you see true state of charge instead of guessing from voltage — which barely moves on a LiFePO4 battery until it is nearly empty.
See options on Amazon (opens in a new tab) - 12 V 100 Ah LiFePO4 batteryPremium price
About 1.28 kWh rated in a box roughly the size of a group 24–31 lead-acid battery at around half the weight. Check the BMS discharge limit and whether it can charge below freezing.
See options on Amazon (opens in a new tab)
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Frequently asked questions
How many kWh is a 48V lead-acid 100Ah bank?
4.8 kWh, about 2,400 Wh usable at 50%.
How many kWh is a 48V 280Ah battery?
14.34 kWh at 51.2 V, about 11,469 Wh usable at 80%.
Other common sizes
- How many watt-hours in a 100Ah battery — 1,280 Wh (12.8 V LiFePO4) or 1,200 Wh (12 V lead-acid)
- How many watt-hours in a 200Ah battery — 2,560 Wh (12.8 V LiFePO4) or 2,400 Wh (12 V lead-acid)
Sources
- Victron Energy — Lithium Battery Smart manual, technical data (opens in a new tab) — LiFePO4 12.8 V: cycle life 2,500 at 80% DoD, 3,000 at 70%, 5,000 at 50% (to 80% of capacity); 92% round-trip efficiency; 12.8 V 100 Ah: recommended continuous discharge ≤100 A (1C), maximum 200 A; capacity about 20% lower at 0 °C; charge only between +5 °C and +50 °C.
- Trojan Battery — Technical support FAQs (opens in a new tab) — “We generally recommend a discharge of 20 to 50% of the battery’s rated capacity even though the battery is capable of being cycled to 80%”; 20-hour and 100-hour ratings; freezing points by state of charge.
- Trojan Battery — 27TMX data sheet (opens in a new tab) — Group 27 flooded: 85 Ah (5-hr), 97 Ah (10-hr), 105 Ah (20-hr), 117 Ah (100-hr); state of charge vs open-circuit voltage table; charger settings.
- Crown Battery — Deep Cycle Battery Product Specifications (effective Oct 1, 2024) (opens in a new tab) — 20-hour capacities by BCI group for flooded, AGM and lithium 12 V batteries.