Load shedding has made one thing very clear to South African households: a fast fibre line is only as useful as the power feeding the equipment attached to it. The moment the lights go out, so does the router, and the connection that felt rock solid a second earlier simply vanishes.
A backup battery seems like the obvious fix, but there is more to it than plugging something in and hoping for the best. Below we look at why your connection drops during an outage, what a battery backup unit actually does for your home network, how to choose the right size for your equipment and what these devices cannot solve on their own.
Why the Power Going Out Takes Your Internet With It
The fibre itself does not need electricity. Light travels down the glass strand without any powered components in the cable, which is why the line running to your home is unaffected by a municipal outage. The problem sits entirely with the hardware on either end of that strand.
Inside your home you have two powered devices in most cases: the ONT, which converts the light signal into something your equipment understands, and the router that shares that connection around the house. Both run off wall sockets, so both switch off the instant the supply is cut.
The same logic applies further up the chain. Aggregation points, exchange equipment and network cabinets all need power too, although these are usually backed up by batteries or generators. That means the weakest link in the chain is very often the small stack of devices sitting in your own home.
What a Battery Backup Unit Does and How Long It Lasts
An uninterruptible power supply sits between the wall socket and your equipment, holding a charge and switching over the instant the mains supply fails. Good units make the handover fast enough that the router never registers a loss, so there is no reboot cycle and no waiting for the line to re-establish itself.
Runtime is where people are often surprised, usually pleasantly. A typical ONT and router combination draws somewhere between 15 and 30 watts in total, which is tiny compared to a fridge or a kettle. Even a modest unit can keep that load running for several hours, and larger models comfortably cover a full load shedding slot.
There are two broad categories worth knowing about. Standard AC units are the familiar tower style boxes that also handle desktops and monitors. Mini DC units are smaller, cheaper and designed specifically for networking gear, feeding the 12 volt supply your equipment already uses without wasting energy on conversion.
Choosing the Right Unit for Your Setup
Start by adding up the wattage printed on the power adapters of every device you want to keep alive. Include the ONT, the router and any mesh nodes or switches that matter to you. Once you know the total draw, you can work out roughly how long a given battery capacity will last.
Resist the temptation to run everything off one unit. Adding a television, a decoder and a gaming console will drain the battery in minutes rather than hours, and it defeats the purpose of a backup power solution for your networking equipment. Keep the load small and focused.
Battery type matters over the long run as well. Lead acid units are cheaper up front but tend to need replacement batteries every two to three years, especially with frequent cycling. Lithium models cost more initially and generally last considerably longer, which often works out better in areas with regular outages.
The Limits Worth Knowing About Before You Buy
A backup unit keeps your equipment powered, but it cannot power the rest of the network. If a fibre node or a nearby cabinet loses power for longer than its own reserves last, your connection will drop regardless of what you have installed at home. This is less common than it used to be, though it does happen during extended outages.
Extended outages also expose the limits of battery capacity itself. Batteries need time to recharge between cycles, and repeated back to back outages will leave a unit only partially topped up. Choosing extra capacity beyond what you think you need is usually money well spent.
Finally, keeping your fibre router running does not help if the devices using the connection are also flat. Laptops and phones hold their own charge, but desktops, televisions and mesh nodes in other rooms will not. Plan the whole picture rather than just the one corner of it.
In Summary
For most households, a small battery backup unit is one of the cheapest and most effective upgrades available. Networking equipment draws very little power, runtimes are generous and the difference between a dead line and a working one during an outage is genuinely significant.
If you are looking for a connection worth protecting in the first place, our fibre and wireless packages are built around speed, low contention and support that answers any hour of the day or night. Get in touch with the team at ON Fibre and we will help you find the right fit for your home.
