Gate motor battery not charging: battery or charger?

Your gate motor runs from its battery all the time, and a charger inside the motor keeps that battery topped up from the mains or from a low-voltage supply. When the battery stays flat, one of three things is happening:

1. The charger has no power to work with. The supply to the motor is off, or a transformer feeding it has been unplugged.
2. The charger has failed, so power arrives but doesn't reach the battery.
3. The battery is worn out, so it accepts current but can't store it.

The first you can usually check yourself. The second and third need a meter and a technician, but the signs below help tell them apart.

• The low-battery signal stays on with the mains on: three flashes on a Centurion D5-Evo or D10, four on an ET Drive, three beeps on a Gemini.
• The mains-failure signal comes on while the rest of the property has power, which points to the supply to the motor, not the battery.
• The gate dies within minutes of a power cut, or manages only a few openings.
• The gate slows down or stops part-way even when the power is on.

If the mains-failure signal is showing, start with the supply. If only the low-battery signal shows, the battery or the charger is the likelier cause.

• The motor's plug or isolator. It sits near the motor or in the house. It may have been switched off, or a breaker may have tripped in a storm. Look at it, and switch it back on if it's simply off; if a breaker trips again, stop and call us.
• A plug-in transformer in the house. Some motors don't take mains at the gate at all. Centurion's D5-Evo Low-Voltage runs from 15 to 19 V AC supplied by a plug-in step-down transformer, typically installed in the house, and ET's Drive 500 can run from a 16 V AC plug-in transformer on quieter sites. If someone has unplugged it to free a socket, or it's on a switched-off plug, the motor runs on its battery until the battery is flat. It's one of the commonest causes we find, and one of the easiest to fix.
• A solar panel. Centurion notes that a solar supply can charge the battery instead of the mains. A panel that's dusty, shaded by a growing tree, or getting less winter sun charges less, and the battery slowly runs down.

Anything on the mains side, such as wiring or a socket, is a job for a registered electrician.

A battery that has been run right down after a long power cut needs hours to recover, not minutes. ET advises at least 8 to 10 hours of uninterrupted charging after a low-battery warning before you check it again. ET's charger also pauses while the gate is moving, so a busy gate straight after an outage charges more slowly still. If the warning is gone the next morning, the battery and charger are probably fine and the battery simply ran flat.

ET's Drive 500 and 600 have a diagnostics screen on the control card that reports exactly what the charger is doing. It's how we tell the two halves apart on an ET in a minute:

On a transformer supply, the same screen should show the AC input at 16 to 19 V; much less, and the transformer or its cable is the fault. A charger reading Turned off isn't always a mistake: ET allows the built-in charger to be switched off where a bigger external charger looks after larger batteries, and then it's that external charger to check.

A battery reaches the end of its life whatever the charger does. Centurion expects at least three years of normal service from a maintenance-free battery, and frequent deep discharges in long outages, heat inside the housing, and months on a weak charger all shorten that. A battery that's swollen, leaking or corroded at the terminals is finished.

The test is simple: once it's fully charged, a good battery holds its voltage under load; a worn one collapses as soon as the motor starts. We test it in place before replacing anything, so you only pay for a battery when the battery is at fault.

Check the plug, the isolator and any plug-in transformer, give the battery a night on the mains, and clean a solar panel if you have one. Leave the rest to us: opening the motor exposes the charger and, on many models, mains connections, and both the battery and the charger need testing with a meter. More on batteries, sizes and prices is on gate motor batteries, and on a gate that won't move at all, see gate motor not working.

On the job card, give the motor's make, what the status light shows, and whether the motor has its own plug at the gate or a transformer in the house. All our spare parts are genuine, every repair comes with our six-month guarantee on our repairs, and same-day repairs are offered when the day allows. No call-out fee when we do the work. If no work is done, a R650 call-out fee applies.