Battery Cells in series add voltage. Cells in parallel add capacity. Once you know the voltage your inverter or motor needs, the cell count follows from the table.
| Battery | LiFePO4 cells in series | Nominal / full charge | Lithium-ion cells in series | Nominal / full charge |
|---|---|---|---|---|
| 12V | 4S | 12.8V / 14.6V | 3S | 11.1V / 12.6V |
| 24V | 8S | 25.6V / 29.2V | 7S | 25.9V / 29.4V |
| 36V | 12S | 38.4V / 43.8V | 10S | 37V / 42V |
| 48V | 16S | 51.2V / 58.4V | 13S | 48.1V / 54.6V |
| 60V | 20S | 64V / 73V | 16S | 59.2V / 67.2V |
| 72V | 24S | 76.8V / 87.6V | 20S | 74V / 84V |
Capacity and energy
A series string has the same amp-hours as one cell. Sixteen 100Ah cells in series are still 100Ah, now at 51.2V. Energy is volts × amp-hours:
| Build | Cells | Layout | Energy |
|---|---|---|---|
| 12V 100Ah | 4 × 100Ah | 4S | 1.28 kWh |
| 12V 200Ah | 8 × 100Ah | 4S2P | 2.56 kWh |
| 24V 100Ah | 8 × 100Ah | 8S | 2.56 kWh |
| 48V 100Ah | 16 × 100Ah | 16S | 5.12 kWh |
| 48V 314Ah | 16 × 314Ah | 16S | about 16 kWh |
How long will it run?
Divide the usable energy by your load. Allow about 10% for inverter losses. A 12V 100Ah battery (1.28 kWh) on a 300W load runs for roughly 1280 × 0.9 ÷ 300 = 3.8 hours. The 24V 100Ah build doubles that.
Parts list for one battery
- Cells, all bought together so they match: LiFePO4 cells.
- A BMS with the same string count: JK BMS. See how to choose one.
- A box to hold and protect the pack: metal battery boxes.
- Terminal, display and fiber tape: pack parts and JK displays.
Or buy it as a kit
We sell the three most common builds as complete kits with AJT 100Ah cells, a JK Smart BMS, a JK 3.2-inch display, terminal and metal box:
- 12V 100Ah complete battery kit (4 cells)
- 12V 200Ah complete battery kit (8 cells)
- 24V 100Ah complete battery kit (8 cells)
Lithium cells can deliver very high current. Insulate your tools, never let a spanner bridge two terminals, and connect the BMS before the first charge. If you would like help planning a pack, message us on WhatsApp at 0332 9891510.