How big a solar panel and battery for a piso Wi-Fi?
A piso Wi-Fi box draws about 0.4 A at 12 V (a router and a coin acceptor), 10 Ah a day. A 100 W panel makes 300–400 Wh on a Cebu day, three times what the box uses; a 12 V 30 Ah LiFePO4 carries two cloudy days. A 12 Ah battery is off before the second morning.
Gaano kalaki ang solar panel at battery para sa piso wifi?
Ang piso wifi box ay kumukuha ng mga 0.4 A sa 12 V (router at coin acceptor), mga 10 Ah bawat araw. Ang 100 W na panel ay gumagawa ng 300 hanggang 400 Wh sa isang araw sa Cebu, tatlong beses ng kailangan; ang 12 V 30 Ah LiFePO4 ay kaya ang dalawang maulap na araw. Ang 12 Ah ay patay na bago ang pangalawang umaga.
See it run
Piso Wi-Fi on solar: how big a panel and battery for a router and coin boxA build with a test sheet: every number on this page is a test you can run.
The numbers
| Router 5 W + coin acceptor 0.5 W | 0.4–0.5 A at 12 V |
| Per day | about 10 Ah (120 Wh) |
| 100 W panel, 4 peak-sun hours | 300–400 Wh: charges the day’s use by noon |
| 12 V 30 Ah LiFePO4 | about 60 h with no sun |
| 12 V 12 Ah SLA (use 50 %) | about 15 h |
| Charge controller | 10 A PWM is enough; MPPT gains 10–20 % on a 100 W panel |
Questions
PWM or MPPT for one 100 W panel?
PWM works and costs a third. MPPT gains 10–20 %, more on cold mornings. For one small panel it is a convenience, not a necessity.
Can I run the box straight from the panel without a battery?
No: the router reboots at every cloud. The battery is the point.
What about a grid charger as backup?
A 12 V 5 A charger on the battery through a diode or a DC UPS module makes the box grid-first with solar topping up, or solar-first with grid fallback. The Router DC UPS build has the changeover.
Is this the whole vending design?
No, only the sizing. Coin handling, the captive portal and the hardware around the box are the business’s own design.
More questions
- Will my solar run the aircon at night?
- Why does my aircon trip the inverter when it starts?
- Does grid-tie solar work in a brownout?
- What keeps the Wi-Fi router up in a brownout?
- What breaker and wire size for an aircon?
- What breaker and wire size for a water heater?
Brownout backup · Piso Wi-Fi on solar · Solar PV simulator · House wiring simulator