Battery Drain Diagnosis page

Battery Drain Diagnosis & Parasitic Drain Testing

If your vehicle battery is repeatedly going flat, there is usually an underlying electrical fault causing excessive battery drain. Modern vehicles contain many control modules and electrical systems which can remain active after the vehicle is switched off, and faults within these systems can cause unwanted battery drain.

Logic Auto Electrical provides specialist battery drain diagnosis using professional diagnostic equipment and proven testing methods to accurately identify the cause of parasitic battery drain.

Rather than replacing parts unnecessarily, faults are diagnosed methodically to locate the root cause of the issue.

Battery Drain Issues

Battery drain problems can be caused by a variety of faults, including:

Control modules failing to enter sleep mode
Faulty wiring or poor connections
Interior lights staying on
Faulty alternators
Aftermarket accessories (dash cams, trackers, stereos)
Faulty relays
CAN bus communication faults
Faulty sensors or modules
Boot, bonnet or door switch faults

These issues can often be intermittent and difficult to diagnose without specialist equipment.

Professional Battery Drain Testing

Battery drain diagnosis involves more than simply checking the battery. I use specialist equipment to:

Measure parasitic drain accurately
Monitor current draw over time
Identify modules that remain active
Perform electrical fault tracing
Analyse live data where required

This allows faults to be diagnosed accurately and avoids unnecessary parts replacement.

Symptoms of Battery Drain

You may have a battery drain issue if you notice:

Battery going flat overnight or after a few days
Vehicle struggles to start after being parked
New battery going flat quickly
Electrical systems behaving unexpectedly
Warning lights appearing intermittently

If you’re experiencing any of these symptoms, professional diagnosis is recommended.

Mobile Battery Drain Diagnosis

Logic Auto Electrical offers a mobile service, meaning diagnostics can often be carried out at your home or workplace.

This is particularly useful for:

Vehicles that won’t start
Intermittent battery drain issues
Convenience and time saving

Get in Touch

If your vehicle battery is repeatedly going flat, get in touch to arrange battery drain diagnosis and fault finding.

Fill in this form to contact us about a battery drain issue.
We will respond quickly to your query.