Question 1

What causes a car battery to go flat overnight in Walthamstow?

Accepted Answer

The most common cause is a parasitic draw — something is draining power from the battery when the car is parked. Typical culprits include an ECU or body control module that fails to go into sleep mode, a poorly installed aftermarket accessory such as a dashcam or stereo, a sticking relay, or a failing alternator diode that allows current to flow backwards. MnF Motors uses an amp-clamp and fuse-pull diagnostic method to locate the exact circuit responsible.

Question 2

How long does a parasitic drain diagnosis take at MnF Motors?

Accepted Answer

In most cases our technicians can identify the offending circuit within one to two hours. Some drain faults caused by modules that take a long time to enter sleep mode can require the vehicle to be left overnight, but we will always advise you upfront.

Question 3

How much does parasitic battery drain diagnosis cost near Walthamstow?

Accepted Answer

Our diagnostic labour is charged transparently with no hidden extras. We will quote you a fixed price before any work begins. Unlike national chains, we do not charge for a generic code-read and call it a diagnosis — our amp-clamp and fuse-pull process is a true electrical investigation.

Question 4

Will I need a new battery if my car keeps going flat overnight?

Accepted Answer

Not necessarily. If the battery has been repeatedly drained it may have suffered sulphation damage and could need replacement, but the priority is always to find and fix the drain source first. Fitting a new battery without resolving the underlying fault means it will simply go flat again.

Question 5

Do MnF Motors offer a warranty on electrical repairs?

Accepted Answer

Yes. All repairs carried out at MnF Motors come with a parts and labour warranty. Full details are on our Warranty Claims page. We have honoured warranties without argument for over 25 years — our 4.9★ Google rating reflects that commitment.