Battery Backup for Your Vallarta Home: What Do You Need to Power?
By the Vallarta Solar Guide editorial team · Published November 1, 2026 · Updated November 1, 2026 · Not technically reviewed yet
Short answer
Size a battery from the appliances you actually need during an outage. Two numbers matter: output power in watts (W), which limits what can run at the same time, and stored energy in watt-hours (Wh or kWh), which limits for how long. Surge loads and conversion losses mean real runtime is lower than simple maths suggests.
W versus Wh — the two numbers to compare
| Spec | Unit | What it tells you |
|---|---|---|
| Continuous output | W (watts) | The maximum load the unit can supply at once. |
| Surge / peak output | W | Short bursts for motors starting (fridges, pumps). |
| Capacity | Wh or kWh | How much energy is stored. |
| Usable capacity | Wh or kWh | What you can actually draw; may be less than nominal. |
A battery with a big capacity but small output can run a fridge for a long time but not a mini-split. One with high output but small capacity can run a mini-split — briefly.
List your essential loads
Check the label (placa) on each appliance for watts, or volts × amps. Typical essentials: refrigerator, lights, internet router, phone charging, fans, and perhaps a water pump or one mini-split.
A hypothetical runtime calculation
- Loads: fridge averaging 100 W, router 15 W, LED lights 40 W, two fans 100 W → about 255 W average.
- Battery: 2,000 Wh nominal; assume 90% usable and 85% inverter efficiency → about 1,530 Wh available.
- Estimated runtime: 1,530 ÷ 255 ≈ 6 hours. Real results depend on temperature, battery age and how often the fridge compressor cycles.
Why mini-splits and pumps need care
Air conditioners and water pumps (bombas para tinaco or hydropneumatic systems) are motor loads. They can draw several times their running power for a moment on start-up and may consume a lot of energy over hours. Inverter-type mini-splits start more gently, but still draw significant power. Before promising yourself “AC during outages”, have a qualified professional measure or calculate these loads.
Portable station or installed home battery?
| Portable power station | Installed home battery | |
|---|---|---|
| Connection | Plug appliances into it | Wired into a backup sub-panel |
| Installation | None for plug-in use | Qualified electrician / installer |
| Typical use | Fridge, router, lights, devices | Selected household circuits |
| Recharging | Wall outlet, solar panels, car | Home solar and/or grid |
Related questions
Can I recharge a portable station with solar during an outage?
Many models accept solar input. Check the input limits (voltage and watts) in the manufacturer’s documentation and use compatible panels.
Sources
This guide explains general principles; check your equipment’s official manufacturer documentation for specific limits.
Official sources are listed as references for rules that can change. Always confirm current requirements with the authority directly. Spotted an error? Send a correction.
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