Combine charging sources, subtract ongoing house loads, and estimate the time required to reach a target state of charge.
Using a generator? Check generator and charger power limits first, then use its battery-side current here.
Only add sources that can realistically operate at the same time and sustain the entered output.
Ah needed = bank Ah × (target SOC% − starting SOC%) ÷ 100net amps = source amps × efficiency − live loadshours = Ah needed ÷ net ampsThe result is an idealized estimate. Lead-acid absorption and charger taper commonly extend the final portion of charging.
High-output alternators and lithium batteries can stress alternators and cabling. Verify regulation, temperature protection, BMS disconnect behavior, source isolation, and overcurrent protection.
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A 200 Ah bank going from 30% to 90% needs 120 Ah. If simultaneous sources supply 40 A, charging efficiency is 90%, and live loads consume 5 A, net charging is 31 A. Estimated recovery is 120 ÷ 31 = 3.9 hours before taper.
No. Use the battery-side DC output of a compatible charger powered by the generator. Generator AC watts and battery DC amps are different quantities. Check generator continuous capacity, charger input demand, and other AC loads.
No. It assumes sustained battery-side current. Lead-acid absorption, lithium balancing, thermal reduction, solar variation, and BMS limits can extend elapsed time, particularly near 100% state of charge.
Set other source currents to zero and enter realistic average solar charging current during productive sun hours. The answer represents productive charging hours, not clock hours across night and cloud cover.