Purpose
Brownouts are a real problem working from home. I wanted a system that keeps my PC, monitor, and router running without interruption — and ideally at zero running cost on sunny days. The build also needed to handle essential house loads: lights, fans, TV, and the fridge (~90W rated).
The result: a 12V hybrid solar system with automatic grid fallback, bridged by a UPS to handle the inverter's ~200ms switchover gap so the PC never sees a power cut.
Components & Pricing
Main Components
| # | Component | Item | Store | Price (₱) |
|---|---|---|---|---|
| 1 | Hybrid Inverter | PowMr 1kW 12V, Built-in 80A MPPT, PV 20–150Vdc, Pure Sine Wave | PowMr LazMall | ₱6,330 |
| 2 | Battery | PowMr 12V 100Ah LiFePO4, Built-in BMS, 10-year lifespan | PowMr LazMall | ₱7,750 |
| 3 | Solar Panel | Hantech 550W Monocrystalline, Single crystal double-sided | Lemon Silk Road (Lazada) | ₱5,499 |
| 4 | UPS Buffer | Prolink 650VA / 390W, Line Interactive, 4 sockets | Prolink LazMall | ₱1,457 |
| Subtotal | ₱21,036 | |||
Mounting Hardware (BuildIt brand — Shopee)
| # | Item | Qty | Price (₱) |
|---|---|---|---|
| 5 | Aluminum Rail 2.2m | 2 | ₱1,038 |
| 6 | End Clamps | 4 | ₱136 |
| 7 | L-Foot GI Roof Brackets | 8 | ₱466 |
| 8 | Mid Clamps (for future 2nd panel) | 2 | ₱68 |
| 9 | Tek screws + rubber washers (16 pcs) | 1 set | ~₱100 |
| 10 | Silicone sealant | 1 tube | ~₱100 |
| Subtotal | ~₱1,908 | ||
Cables & Electrical Accessories
| # | Item | Est. Price (₱) |
|---|---|---|
| 11 | Solar cable 6mm² with MC4 connectors (~10m) | ~₱800 |
| 12 | Battery cables 16mm² thick gauge (keep under 1m) | ~₱500 |
| 13 | DC breaker — between panel and inverter | ~₱350 |
| 14 | DC fuse 100A — between battery and inverter | ~₱350 |
| 15 | AC breaker — on inverter output side | ~₱200 |
| 16 | Grounding kit — ground rod + wire | ~₱300 |
| Subtotal | ~₱2,500 | |
Safety Gear
| Item | What For | Est. Price (₱) |
|---|---|---|
| Insulated gloves (1000V rated) | Protects from electrocution | ~₱200–500 |
| Voltage tester pen | Quick check if wire is live | ~₱50–150 |
| Digital multimeter | Accurate voltage readings, solar DC testing | ~₱300–500 |
| Insulated screwdrivers | Safe terminal work | ~₱150–300 |
| Rubber slippers/shoes | Ground insulation | ~₱0 (already owned) |
| Subtotal | ~₱700–1,450 | |
Hand Tools
| Item | What For | Est. Price (₱) |
|---|---|---|
| Wire stripper | Stripping wire insulation cleanly | ~₱150–300 |
| Wire cutter / pliers | Cutting wires, bending, holding | ~₱100–200 |
| Long nose pliers | Tight spaces, bending wire ends | ~₱100–200 |
| MC4 crimping tool | Crimping MC4 connectors | ~₱200–400 |
| MC4 spanner / wrench | Tightening MC4 connectors | ~₱50–100 |
| Electrical tape | Insulating connections | ~₱30–50 |
| Cable ties (zip ties) | Organizing and securing cables | ~₱50 |
| Hex / Allen key set | Inverter/battery hex bolt terminals | ~₱100–150 |
| Adjustable wrench | Battery terminals, mounting bolts | ~₱150–250 |
| Heat shrink tubing (optional) | Cleaner insulation than tape | ~₱50–100 |
| Cable lugs + crimper (optional) | Proper battery cable termination | ~₱200–400 |
| Labeling tape / marker | Label wires for future reference | ~₱30 |
| Subtotal | ~₱1,100–2,000 | |
Grand Total
| Category | Cost (₱) |
|---|---|
| Main components | ₱21,036 |
| Mounting hardware | ~₱1,908 |
| Cables & electrical | ~₱2,500 |
| Safety gear | ~₱700–1,450 |
| Hand tools | ~₱1,100–2,000 |
| Grand Total | ~₱27,244–28,894 |
Battery was ₱5,800 on sale. Non-sale price of ₱7,750 used above. On sale, total drops by ~₱1,950.
Where to Buy
- Inverter — PowMr 1KW 12V Hybrid Solar Inverter 230Vac Built-In 80A MPPT Pure Sine Wave (LazMall)
- Battery — PowMr 12V 100AH LiFePo4 Battery With Built-in BMS, 10-Year Lifespan (LazMall)
- Solar Panel — Hantech 550W Monocrystalline Solar Panel (Lazada) — select 550W variant
- UPS — Prolink 650VA 390W Line Interactive UPS 4 sockets (LazMall)
- Mounting — BuildIt brand from Aluminum Power store on Shopee: Rails 2.2m, End Clamps, L-Feet, Mid Clamps
System Specifications
| Spec | Value |
|---|---|
| System voltage | 12V |
| Battery capacity | 12.8V × 100Ah = 1,280Wh |
| Usable capacity | ~1,000–1,100Wh (after inverter losses & BMS cutoff) |
| Max solar input (MPPT) | 80A × 12V = 960W |
| Panel output (usable) | ~550W (within 960W MPPT limit) |
| Inverter max output | 1,000W continuous |
| UPS pass-through | 390W (for PC setup) |
| PV input voltage range | 20–150Vdc |
What I Can Run
Daily Solar Harvest (Estimated)
| Condition | Peak Sun Hours | Harvest (after 20% losses) |
|---|---|---|
| ☀️ Sunny day | 5 hrs | ~2,200Wh |
| 🌤️ Average day | 4 hrs | ~1,760Wh |
| ☁️ Cloudy day | 2.5 hrs | ~1,100Wh |
Runtime on Battery Alone
| Load | Watts | Runtime |
|---|---|---|
| PC + Monitor + Router | ~200–300W | 3.5–5.5 hours |
| Essential house (lights, fan, TV, router) | ~250W | ~4 hours |
| Light load (router only) | ~15W | 60+ hours |
With solar supplementing during daytime, runtime extends significantly.
Wiring Diagram
12V Solar Backup System — Wiring Diagram
PowMr 1kW Hybrid Inverter · 12V 100Ah LiFePO4 · 550W Panel · Prolink UPS
Wire Color Legend
Mounting Layout
Landscape orientation on GI roof. One 550W panel across two 2.2m aluminum rails, secured with 8 L-foot brackets into the purlins.
←──────── 2.2m ────────→
[EC]══ Rail 1 (2.2m) ══[EC] ↑
│ │ │ │ │ │ │ │ │
LF LF LF LF LF LF LF LF 1.1m
│ │ │ │ │ │ │ │ │
[EC]══ Rail 2 (2.2m) ══[EC] ↓
╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲ ← GI sheet roof
EC = End clamp (4 total)
LF = L-Foot bracket (8 total, screwed into purlins)Wiring Order
Follow this sequence exactly. Connecting in the wrong order risks short circuits.
Inverter Settings
- Battery type: LiFePO4
- Charge priority: Solar first, grid second
- Charge voltage: 14.2V–14.6V (verify against your battery's spec sheet)
Power On / Off Sequence
Safety
Electrical Safety Rules
- ⚡Test TWICE, touch ONCE — always verify wires are dead before touching
- ⚡Work with one hand only when possible near live terminals
- ⚡Work in dry conditions — no wet hands, no wet floor
- ⚡Tape the breaker with "DO NOT TURN ON" when working on circuits
- ⚡Tell someone you're working on the electrical system
- ⚡Never rush — most accidents happen when skipping safety steps
Wire Identification (Philippine Standard)
| Wire | Color | Role |
|---|---|---|
| Line (Live/Hot) | Red or Black | ⚡ Dangerous |
| Neutral | White or Blue | Treat with caution |
| Ground | Green or Yellow-Green | Earth connection |
Never rely on color alone — always verify with a tester or multimeter before touching.
Upgrade Path
The system is designed to grow. Here's where it can go from here.
🔋 Battery Expansion
Add a second 12V 100Ah in parallel for 2,560Wh total. Same model recommended. Up to 4 units supported by the battery spec.
☀️ Solar Panel Expansion
Inverter MPPT handles up to 960W. A ~400W second panel is ideal. Mid clamps already purchased. Alternatively, wire two panels in series (stay under 150Vdc).
📡 Standalone MPPT
The built-in 80A MPPT can't be swapped, but you can add a separate MPPT controller alongside it to connect more panels beyond the 960W limit.
⚡ Inverter Upgrade
Swap to a 2kW or 3kW 12V hybrid later — or jump to 24V/48V for 3–6kW+ systems. Panels and accessories carry over; batteries need reconfiguring for higher voltages.
🏠 Full House Power
Current 1kW inverter handles essentials (~600–700W). For AC units and whole-house: 5kW+ hybrid inverter + more batteries + more panels. Estimated: ₱80,000–150,000+.
🔄 Grid-Tie (Future)
Current setup is off-grid only. Grid-tie requires a separate grid-tie inverter + net metering agreement with Meralco + bidirectional meter. Both systems can coexist side by side.
Running cost on a sunny day: ₱0. Grid backup days: ~₱100–300/month. For a WFH setup that survives brownouts and pays for itself over time, this build hits the sweet spot.