Back-Up Home Power True Sine Wave Battery Backup Systems

How to Choose the Right Inverter for Load Shedding in South Africa

Load shedding has become part of daily South African life. Whether you're on Stage 2 or Stage 6, finding yourself in the dark for 2–4 hours at a stretch is frustrating — and for many households, genuinely damaging to food, work, and security. A well-chosen home inverter system solves this problem permanently.

But walk into any electrical shop or browse online and you'll face a wall of options: pure sine wave vs modified sine wave, 1kVA vs 5kVA, lead-acid vs lithium, hybrid vs standalone. This guide cuts through the confusion and gives you the straight South African picture on what to buy, what to spend, and what to avoid.

Step 1: Calculate Your Load (What Do You Actually Need to Run?)

The single most important step is knowing how much power you need. List every appliance you want to run during load shedding and note its wattage. Here are typical South African household loads:

ApplianceTypical WattagePriority
LED lights (x6)60WEssential
Wi-Fi router15WEssential
Laptop/PC60–150WHigh
LED TV (55")80–120WMedium
DStv decoder30WMedium
Fridge (medium)150–200W running / 600W startupHigh
Microwave900–1200WLow (brief use)
Kettle / toaster1500–2200WAvoid on inverter

Pro tip: Kettles and geysers are power-hungry. Unless you have a large battery bank and a big inverter, leave those on grid power and focus your inverter on essentials.

Rule of thumb: Add up the wattage of everything you want to run at the same time. Choose an inverter rated at least 20–25% higher than that total to handle startup surges and leave headroom.

Step 2: Pure Sine Wave vs Modified Sine Wave — There Is Only One Answer

You'll see modified sine wave inverters at lower prices and it's tempting. Don't do it for a home setup. Here's why:

For a home backup power system, always choose a true sine wave inverter. The price difference is modest and the protection it offers your appliances is worth every rand.

Step 3: Choosing the Right Inverter Size (kVA)

Inverters are rated in VA (volt-amps) or kVA. For practical purposes, treat 1kVA as roughly equal to 800W of usable power (accounting for inefficiency).

System SizeWhat It RunsBest For
1kVA – 1.5kVALights, router, TV, phones, laptopApartment, small home
2kVA – 3kVAAbove + fridge, ceiling fanMedium family home
4kVA – 5kVAAbove + additional appliances, small washing machineLarge home, home office
8kVA+Near full-house coverageLarge property, business

If you're primarily protecting essentials — lights, internet, TV, laptops, phone chargers — a 2kVA system is the sweet spot for most South African family homes. Add the fridge and you may want to step up to 3kVA.

Step 4: Standalone Inverter vs Hybrid Inverter

This is a crucial decision that affects your upgrade path:

Standalone / UPS Inverter

Connects to your battery bank and switches to battery when grid power fails. Charges batteries from grid power when Eskom is on. Cannot accept solar panels. Lower cost upfront, but a dead-end if you later want to add solar.

Hybrid / Solar Inverter with MPPT

Does everything a standalone does, but also accepts solar panel input via a built-in MPPT (Maximum Power Point Tracking) charge controller. During daylight hours your solar panels charge batteries and offset grid draw — even when Eskom is on. This is the smart long-term choice.

Recommendation: If you can stretch the budget, buy a hybrid inverter now. Even if you can't afford solar panels immediately, you'll be able to add them later without replacing your inverter. Think of it as future-proofing your investment.

Step 5: Battery Type — Lead-Acid vs Lithium

Your battery bank is where most of your money goes. You have two main choices:

Sealed Lead-Acid (AGM/Gel)

Lithium Iron Phosphate (LiFePO4)

When you calculate cost over time, lithium often wins. Read our detailed comparison in Lithium vs Lead-Acid Batteries for Home Backup Power for the full breakdown.

Step 6: How Much Battery Capacity Do You Need?

Battery capacity is measured in amp-hours (Ah). To calculate how long your system will last:

  1. Determine your total load in watts (e.g., 400W)
  2. Decide how many hours you need (e.g., 4 hours for a Stage 4 double slot)
  3. Energy needed: 400W × 4h = 1,600Wh = 1.6kWh
  4. For lead-acid (50% usable): you need 3.2kWh of rated capacity
  5. For lithium (85% usable): you need 1.9kWh of rated capacity

This is why lithium gives you so much more real-world runtime for the same rated capacity — and why the price premium is often justified.

Installation and Safety

A properly installed inverter system should be wired by a qualified electrician and connected to a dedicated DB board circuit. Key points:

Ready to get a professional assessment? Contact us or use our Home Backup Systems request form for a free quote.

Estimated Costs for a South African Home (2026)

SystemApproximate Installed Cost
1.5kVA + 100Ah AGM (essentials only)R10,000 – R15,000
3kVA + 200Ah AGM (fridge + essentials)R22,000 – R32,000
3kVA Hybrid + 100Ah LithiumR28,000 – R40,000
5kVA Hybrid + 200Ah Lithium + 2kWp SolarR55,000 – R85,000

Frequently Asked Questions

What size inverter do I need for load shedding at home?

For a typical South African home running lights, TV, router and phone chargers, a 1kVA to 2kVA inverter is sufficient. If you also need to run a fridge, bump up to 3kVA–5kVA. Always add up the wattage of every device you want to run simultaneously and choose an inverter rated at least 20% above that figure.

How long will an inverter last during load shedding?

Runtime depends entirely on your battery bank capacity and your load. A 100Ah 12V lead-acid battery powering a 200W load will last roughly 4–5 hours. Lithium batteries (same Ah) deliver closer to 6–7 hours because you can safely discharge them deeper.

What is the difference between a pure sine wave and modified sine wave inverter?

A pure sine wave inverter produces clean AC power identical to Eskom supply — safe for all appliances including sensitive electronics, motors and compressors. Modified sine wave inverters are cheaper but can damage some appliances and cause humming in audio equipment. For home use, always choose pure sine wave.

How much does a home inverter setup cost in South Africa?

A basic 1kVA pure sine wave inverter with a 100Ah sealed battery starts around R8,000–R12,000 installed. A 3kVA system with lithium batteries capable of running your home through a 4-hour load shedding slot typically costs R25,000–R45,000.

Can I add solar panels to my inverter system later?

Yes — if you purchase a hybrid inverter (also called a solar inverter or inverter-charger with MPPT input), you can add solar panels at any time. Make sure your inverter has a built-in MPPT charge controller. This is the most future-proof option for South African homes.