Storm Season and Your Automatic Gate: Battery Backup, Surges and Flooding

Spring and summer in South East Queensland bring afternoon storms that can drop hail, flatten trees and knock the power out across whole suburbs. Storm season is generally described as running from around October to April, and the Bureau of Meteorology issues severe thunderstorm warnings when it expects storms to produce large hail or damaging wind gusts. For anyone with an automatic gate, those warnings are a good prompt to think about what happens when the power goes off.

What happens to your gate in a blackout

Most residential gate motors in Brisbane run on low-voltage DC power with a backup battery. Mains power charges the battery, and the battery runs the motor. When the power drops, the gate keeps working from the battery for a limited number of cycles.

How many cycles depends on:

• The size and age of the battery
• The weight of the gate and how freely it moves
• Accessories that draw power around the clock, such as safety beams, intercoms and keypads

A healthy battery on a light aluminium gate might get a household through a short outage comfortably. An old battery on a heavy gate might manage only a few cycles. Ask your installer what to expect from your setup.

Batteries wear out

Backup batteries are consumables. Heat, age and repeated deep discharge all shorten their life. A common pattern is a gate that seems fine for years, then fails during the first long outage of the season because the battery had quietly lost most of its capacity. A battery test during regular servicing catches this before it matters.

Know your manual release

Every automatic gate should have a manual release, usually a key or lever on the motor that disengages the gearbox so the gate can be pushed by hand. Before storm season:

• Find the release key and keep it somewhere you can reach without opening the gate
• Practise using it once, in daylight, so you know how
• Re-engage the motor afterwards, or the gate will not move under power

Never force a gate while the motor is engaged. You can strip the gearbox or damage the rack.

Surges and lightning

Storms do not just cut power. When it comes back, or when lightning strikes nearby, the voltage spike can damage the gate's control board. A gate that is dead the morning after a storm, even though the house power is back, often has a damaged board.

Earthing and surge protection reduce the risk. Ask your installer how the controller is earthed and whether surge protection is included. Any work on the mains supply side must be done by a licensed electrician in Queensland.

Hail and wind

Hail can dent aluminium slats and damage solar panels on solar-powered gates. Strong gusts put real load on solid gates, which act like a sail. If you are choosing a new gate in an exposed spot, a slatted design with small gaps lets wind through and reduces strain on the motor and track. You can compare styles in the online gate designer.

Falling branches are the other risk. If a large tree overhangs the gate or the motor, it is worth having it assessed.

Water and flooding

Heavy rain and overland flow can reach gate motors on low driveways and fill the pits that underground swing gate motors sit in. Brisbane City Council's Flood Awareness Map shows the likelihood of river, creek, storm tide and overland flow flooding for addresses in Brisbane, and its FloodWise Property Report gives more detail. Logan, Ipswich, Redland and City of Moreton Bay councils have their own flood information.

If you are in a mapped area or a known low spot:

• Mount the motor and controller as high as practical
• Avoid underground motors unless drainage is excellent
• Keep sliding gate tracks clear so water drains rather than pools

If your gate motor has been under water, do not run it. Have a technician check it first.

Solar gates in storm season

Solar gate kits keep working when the grid goes down, which is a real advantage in an outage. The trade-off is that a run of cloudy, rainy days reduces charging. A well-sized system has enough battery reserve to ride through that. Our solar gate automation page explains how that sizing works.

A pre-season checklist

• Test the gate on battery by switching off its power at the switchboard for a few cycles
• Find and test the manual release
• Clear the track, beams and motor housing of leaves, webs and nests
• Check overhanging branches
• Book a service if the gate has been slow or the battery is a few years old

After the storm

If the gate does nothing once power is back, check the switchboard and any safety switch first. If those are fine, use the manual release and get a technician to diagnose it. Tell us what the gate is doing and we will connect you with a local technician through our gate repairs service.