Does A Motorcycle Alarm Drain The Battery?

A motorcycle alarm is one of the best ways to protect your bike from theft. However, many people are under the impression that installing an alarm will drain your battery and leave you stranded when you’re out and about! So does a motorcycle alarm really drain your battery? Let’s find out.

Yes, it can. If the alarm is faulty, it will drain your battery. Also, if your alarm is wired into your ECU and you leave your motorcycle for long periods between using it, it will drain the battery.

Does an alarm drain the battery?

If you have a poorly wired alarm system, it can drain your battery overnight. If you are not riding your motorcycle frequently, your alarm will drain your battery.

If the dealership or the manufacturer has fitted your alarm, you can guarantee the alarm is connected to the ECU.

This, under normal circumstances, would be the perfect deterrent for any would-be thieve with plans for your motorcycle.

But to the disgruntlement of some motorcycle owners having your alarm system connected to the ECU is less than satisfactory.

If your alarm is connected to the ECU, you can not disarm it without leaving your motorcycle vulnerable, like leaving the keys in the ignition!

The problem arises if you use your motorcycle as a secondary means of transport and not your daily commute.

The slight power draw for your alarm over a few weeks could be sufficient to drain your battery, and when you expect to ride your bike, you can’t.

Aftermarket alarms can be disarmed, and there will be no power drain. It kind of defeats the purpose of the alarm, but at least you can ride your motorcycle without charging your battery.

What drains the battery on a motorcycle?

Bad terminal connections

If you have a bad connection, your battery can drain. If your terminals are corroded, you can expect your battery to drain.

Your alternator may be working perfectly, but it will be impossible for your battery to charge with a poor battery connection.


Most of you add a phone charger and other accessories like heated handlebar grips.

If there is faulty wiring or a dodgy earth lead, this will cause your battery to drain.

Bad battery

Your problems may be with the battery. Depending on the climate, your battery has a finite life. It’s impossible to say how long your battery will last because it depends on many factors like your riding style and frequency of riding.

Should I put an alarm on my motorcycle?

It could be a requirement from your insurance company to have an alarm fitted, so check your policy to make sure you comply with the terms and conditions.

With approximately 21,000 bikes being stolen in the UK every year, you can consider your motorcycle is at risk from theft.

It’s a good idea to protect your assets with alarm systems. If your motorcycle is stolen, then you can expect your insurance premiums to rise the following year regardless of whether your motorcycle was returned.

An alarm will deter the opportunist thief and could give you enough time to contact the police if the thief is more determined to steal your motorcycle.