South Africans who cannot afford a fully-fledged backup power system have a range of cheaper options available that can keep certain key appliances powered during load-shedding.
Eskom has warned that load-shedding will likely be necessary throughout winter and recently implemented stage 4 load-shedding yesterday evening.
This comes as the utility is faced with severe supply shortages due to breakdowns, and is also undertaking planned maintenance of its ageing infrastructure.
A battery backup system that can charge when power is available and then provide electricity during an outage is one of the best solutions to fight load-shedding.
However, the batteries and inverters required for these systems are still too expensive for the average household.
Even a small load-shedding kit with a 3kW inverter and 2.4kWh storage will cost you more than R20,000.
If you simply want to keep your Internet working while connecting via battery-powered devices such as a laptop or smartphone, then your best option is a small uninterruptible power supply (UPS) or power bank with a DC port.
The power consumption of your Wi-Fi router will be the important factor to consider, and in the case of fibre connections, the optical network terminal (ONT) as well.
According to Energy Use Calculator, the average router uses about 6 watts (W) of electricity. For two and a half hours of load-shedding, you will therefore need a system that can provide at least 15 watt hours (Wh).
Note that certain fibre providers don’t have backup power for their networks before they reach the home, so it advisable to check with your provider first before purchasing backup power for your router.
Below are several smaller UPS devices capable of providing power to a typical Wi-Fi router for a single session of load-shedding.
Generic 8,800mAh Mini UPS (33Wh) – R545
Generic 12,000mAh Backup Battery Power Bank (44Wh) – R626
Gizzu 8,800mAh Mini Dual DC UPS (32Wh) – R999
UltraLAN 16,700mAh Micro UPS (65Wh) – R1,185
Vizia UPS for Wi-Fi router (28Wh) – R1,199
Just your computer or TV
Being able to use your computer or TV will allow you to keep working or stay entertained to pass the time until the power returns.
The average desktop computer, with peripherals, draws around 200W of power and consumes approximately 500Wh in two and a half hours of load-shedding.
The average 55-inch TV with LED backlight has a power output of less than 60W, which means would use around 150Wh of electricity in the same time.
The cheapest option for running your TV or computer for a short duration without power would therefore be a UPS.
It’s important to note, however, that most UPSs use lead-acid batteries, which are not designed to be discharged beyond 50% without significant losses in capacity.
The watt-hour capacity of your UPS should therefore be at least double that of the total consumption of your computers during load-shedding.
Deep cycle batteries can be used to improve this performance somewhat, but at a greater cost.
The preferable option for running over a long time would require adding more batteries or rather using a power trolley, which combines an inverter and high-capacity battery capable of deeper discharge.
Laptops generally draw less than desktops and with newer models supporting USB-C power delivery, you might be able to power it with a large power bank.
While a laptop can be charged and would likely last for two hours of load-shedding, more power-hungry models won’t be able to run at full capacity without being plugged in.
Below are some of the best power trolleys. UPSs and battery banks to power a computer or TV during load-shedding.
It is important not to confuse the wattage with watt-hour capacity, as this is only the measure of momentary power the UPS can deliver at any given time.
The UPS units below typically come with 12V batteries ranging between 84Wh and 108Wh in capacity.
GiCOM 3,000VA online UPS (2,700W) – R4,599
Mecer Winner Pro ME-2000-WPTU (1,600W) – R4,463
RCT 2,000VA Online Tower UPS (1,600W) – R4,719
Mecer 1,200VA Inverter + 1,400Wh Battery (720W) – R4,996
RCT MegaPower 54,000mAh Power Bank (200W) – R3,283
Vizia AC 40,000mAh Power Bank for Laptops (150W) – R3,499
Yoobao 80,000mAh Quick Charging Power Station (300W) – R4,399
RCT MegaPower 80,000mAh Power Bank (200W) – R4,727
Loud but cheap
Backup power for your whole house at R5,000 or less is not feasible, but there are several small petrol generators on the market that can provide adequate power to keep at least a few appliances running.
While you may not be able to use multiple demanding appliances like heaters, stoves, ovens, geysers or any that use elements, a 1,200W unit can at least keep your refrigerator, lights, TV, and a few computers running.
Just keep in mind that generators are generally very loud, so a sound-proofing solution will go a long way to keeping the neighbours happy.
In addition, they require topping up every so often, so remember to take fuel costs into account.
Mac Afric 0.8kVA petrol generator (650W) – R1,895
Mac Afric 1.25kVA petrol generator (1,000W) – R2,999
Ryobi 1.2kVA generator with AVR (1,000W) – R3,599
Mac Afric 2.8kVA generator (2,000W) – R3,995