Guide
Charge time is set by the supply, the charger and the battery's C-rate.
Hours to charge ≈ energy to replace (kWh) ÷ charging power (kW), plus a little for losses and the slower final top-off. The charging power is limited by whichever is smallest: the supply, the charger, or the battery's maximum charge rate.
| Energy to replace | Charging power | Approximate time |
|---|---|---|
| 12 kWh | 1.8 kW (15 A, 120 V) | About 7 hours |
| 24 kWh | 3.75 kW (generator input) | About 6 to 7 hours |
| 24 kWh | Solar, 6 kW peak | Most of a sunny day |
| 1 MWh (Leberi) | 0.5C rate | About 2 hours minimum |
Most sites recharge overnight or from solar while the battery works. See charging methods.
Three things set the ceiling. The supply: a 15 A, 120 V outlet can only deliver about 1.8 kW. The charger: the unit's built-in charger and inverter have a maximum input. The battery: every pack has a maximum safe charge rate, and a BMS slows charging as the pack approaches full.
That final slowdown is normal. The last 10 percent or so takes longer than the rest, which is why charge-time estimates should include a margin.
Temperature matters too. Charging LFP cells below freezing is restricted to protect them, so in cold weather the BMS may hold off charging until the pack warms.
Questions answered
Energy to replace divided by charging power; overnight on a standard supply for a trailer.
Charge or discharge power relative to capacity. 0.5C means a full charge takes about two hours.
Yes. With solar or a generator input, the battery can recharge while it supplies the load.
Keep reading
Get in touch
Tell us the site, the load and the runtime you need. Our Austin engineering team comes back with a configuration, a runtime estimate and a price.
+1 512-316-7347
info@pulsar.industries
WhatsApp +1 512-585-8293
