You need ≈ 13.8 kWh nominal (288 Ah at 48 V). With 12.8 V 100 Ah units: 4 in series × 3 in parallel = 12 units, 15.36 kWh.
Configuration
4S3P
12 × 12.8 V 100 Ah
Required capacity
13.8kWh
288 Ah at 48 V
Installed bank
15.36kWh
300 Ah at 51.2 V
Usable energy (new)
11.2kWh
80% DoD, temp. 94%
Actual autonomy (end of life)
1.7days
target 1.5 days
Peak discharge current
63A
0.21C · bank limit 300 A
Units in series
4
12.8 V × 4 = 51.2 V
Parallel strings
3
fuse each string
Same requirement at other system voltages
| System | Layout | Units | kWh | Ah needed | Peak A | Status |
|---|---|---|---|---|---|---|
| 12 V | 1S11P | 11 | 14.08 | 1,152 | 252 | OK |
| 24 V | 2S6P | 12 | 15.36 | 576 | 126 | OK |
| 48 V | 4S3P | 12 | 15.36 | 288 | 63 | OK |
Sizing steps
| Step | Wh |
|---|---|
| Daily energy at battery terminals | 5,376 |
| × days of autonomy | 8,065 |
| ÷ discharge efficiency | 8,314 |
| ÷ depth of discharge | 10,392 |
| ÷ temperature factor | 11,056 |
| ÷ end-of-life capacity | 13,820 |
- Series: voltages add, Ah stay the same. Parallel: Ah add, voltage stays the same. Always use identical units of the same age; connect parallel strings with equal cable lengths (diagonal or busbar wiring) and fuse each string.
- Lithium banks need a BMS per series string; DIY cell packs need a balancer and cell-level fusing.