How long does a gate motor battery last?

Centurion says its maintenance-free batteries should give at least three years of normal service. Some last longer; many last less, and the reasons are nearly always the same:

• Deep discharges. Every power cut that runs a battery right down takes something out of it. Long, frequent outages age a battery more than anything else.
• Heat. A motor housing in full afternoon sun gets hot, and heat shortens a lead-acid battery's life.
• A tired charger. A battery that's never quite fully charged sulphates and loses capacity.

Motors try to protect their batteries. Centurion's D5-Evo shuts down below 10.5 V, and the D10 below 21 V, to stop the battery being run completely flat. Even then, the controller, beams and other devices keep drawing current, more slowly. For the D5-Evo, Centurion offers an optional low cut-out switch that disconnects the battery altogether before it's fully discharged.

The makers give the number of openings a battery should manage when the mains fails, usually over half a day and over a full day of outage, since the electronics draw current even while the gate is still. Centurion's tables for its SMART motors show just how much the gate matters, by the force needed to push it (in kilograms-force) and the speed it's set to:

Read across the D5-Evo SMART rows: the same battery gives about twice as many openings on a gate that slides easily as on a stiff one. And the D6's power-saving mode, at half the speed, doubles the count again.

• Centurion D10: 87 openings over half a day and 69 over a full day on 7 Ah batteries, and 507 and 489 on a 35 Ah battery.
• ET Drive 1000: about 100 on its standard 5 Ah battery, or 150 with two 3.5 Ah batteries, on a 5 m gate needing under 15 kgf. ET adds that it depends on the battery's health and charge when the power fails.
• Centurion Vantage V400 and V500 (swing): 70 over half a day and 58 over a full day on a double kit's 7 Ah battery.
• Centurion SDO4 (garage): 12 to 30 operations, depending on the door's size, weight and height, the length of the outage and the batteries' condition.

The figures for the D5-Evo, ET Drive 500 and 600 and Gemini motors are on our gate motor batteries page.

• Keep the gate running freely. It's the biggest single factor in the tables above: clean the rail, and have worn wheels, guide rollers and a dropped gate seen to.
• A bigger battery or more batteries, where the motor allows it. Centurion notes that a larger battery gives longer standby, and ET's Drive 1000 takes a second battery.
• A slower or power-saving setting, on motors that have one.
• Fewer accessories on the battery. Beams, keypads, lights and receivers all draw current, day and night.
• A charged battery when the power goes, which means a healthy charger and a battery given time to recover between outages.

After a low-battery warning, ET advises at least 8 to 10 hours of uninterrupted charging before checking the battery again. The motor's charger refills the battery slowly and carefully, to protect it, so a battery that ran flat in the evening is usually ready by morning. Back-to-back outages that never allow that time are what catch people out: each one starts with less in the battery than the last.

If the low-battery warning is still on after a full night with the power on, see battery not charging.

The makers in our sources don't publish a life for remote batteries, and it varies with how often the remote is used. The sign that it's going is the same on every remote: shorter range, so you have to be closer to the gate before it opens. Keep a spare battery of the right type at home. If a new one doesn't help, see gate remote not working.

Replace the battery (here's how it's done) when it no longer gets you through a typical outage, when the low-battery warning comes on soon after the power fails, or when the battery is swollen, leaking or badly corroded. We test it in place first, with the charger, so you only pay for a battery when the battery is what's failing. All our spare parts are genuine, and every repair comes with our six-month guarantee on our repairs. No call-out fee when we do the work. If no work is done, a R650 call-out fee applies.