Can I run my aircon on a solar battery?

Yes, with a big enough inverter and battery. A 1 kW aircon uses about 1 kWh an hour, so it shortens backup time a lot.

Does a grid-tie system work in a brownout?

No. A grid-tie inverter shuts down when the grid fails. You need a hybrid or off-grid system with a battery for backup.

Will the battery recharge during a long brownout?

Yes. In a hybrid system the panels keep charging the battery during the day, even while the grid is down.

Battery backup in brownouts

By The Solar Company PH · Updated November 5, 2026 · All solar guides

Short answer

A solar battery powers your chosen circuits when the grid goes down. Backup hours equal the battery’s usable kWh divided by the load in kW. A 16 kWh LiFePO4 battery, about 14 kWh usable, runs a 0.5 kW load of lights, fans, ref and Wi-Fi for about 28 hours.

Typical essential loads during a brownout (estimates)
Appliance	Typical power
LED lights (10 bulbs)	≈ 100 W
Electric fans (2)	≈ 120 W
Refrigerator (average)	≈ 150 W
Wi-Fi router	≈ 15 W
TV	≈ 100 W
Total	≈ 0.5 kW

How battery backup works

In a hybrid system, the inverter watches the grid. When it fails, the inverter switches your backed-up circuits to the battery, usually within a fraction of a second. In the day, the panels keep running those circuits and recharge the battery.

How much energy does a battery store?

Battery energy in kWh = voltage × amp-hours ÷ 1,000. For example, a 51.2 V battery rated 314 Ah stores 51.2 × 314 ÷ 1,000 ≈ 16 kWh. LiFePO4 batteries are normally used to about 90% of that, so about 14 kWh is usable.

How long will it last?

Backup hours = usable kWh ÷ load in kW. With the essentials above, about 0.5 kW: 14 ÷ 0.5 = about 28 hours, before any solar recharging. Add a 1 kW aircon and the load becomes 1.5 kW, about 9 hours.

Why LiFePO4?

Lithium iron phosphate (LiFePO4) batteries handle daily cycling and heat better than lead-acid, can be used to a deeper depth of discharge, and are a stable lithium chemistry. That makes them the usual choice for home solar in the Philippines.

Common questions

Can I run my aircon on a solar battery?: Yes, with a big enough inverter and battery. A 1 kW aircon uses about 1 kWh an hour, so it shortens backup time a lot.
Does a grid-tie system work in a brownout?: No. A grid-tie inverter shuts down when the grid fails. You need a hybrid or off-grid system with a battery for backup.
Will the battery recharge during a long brownout?: Yes. In a hybrid system the panels keep charging the battery during the day, even while the grid is down.