What backup power do you actually need?
Most people buy a UPS that is too small, or an inverter far bigger than they need. Tick what has to stay on, say how long for, and this works out the size — the same sums we do before quoting an install.
What has to stay on?
Tick what matters. Leave out anything that can wait — every extra watt costs battery.
Home
Fibre router / ONT
10 W
Wi-Fi mesh node
8 W
Laptop (charging)
65 W
Desktop PC + monitor
175 W
Gaming / workstation PC
400 W
TV + decoder
105 W
Business
POS till + slip printer
120 W
Card machine
10 W
CCTV recorder (NVR/DVR)
40 W
IP camera
6 W
Server / NAS
60 W
Alarm panel
15 W
Gate motor
300 W (while running)
Office printer (idle)
20 W
For how long?
Runtime drives battery cost far more than the inverter does.
Your estimate
185 W
Total running load
400 VA
Inverter / UPS size
includes 25% surge headroom
370 Wh
Energy for 2 h
Lead-acid battery
75 Ah @ 12 V
Cheaper up front. Only half the capacity is usable, and it wears faster.
Lithium (LiFePO₄)
45 Ah @ 12 V
Smaller and lasts several times longer. Costs more today, less per year.
An inverter trolley
A wheeled inverter with a built-in battery covers this without any wiring work — plug the equipment straight into it.
These are planning estimates from typical power draws, not a quote or an electrical design. Real equipment varies, and anything wired into your distribution board must be installed by a qualified electrician. We'll confirm the real numbers on site before quoting.
We fit these, not just sell them
Supply, installation and the wiring in between — for homes, shops and offices from Umtentweni right through to Port Edward and the surrounding areas. If you would rather we just checked your setup first, that visit is free.