[Ajcar]

My son has just bought a 2014 Ford ka which is his first car. He has had it for 6 months and during that time, the car has had 3 new batteries installed. Something is obviously draining the battery but we've been to 2 separate garages and each time they've just said it is a battery issue and replaced. It has now got to the point that he has to drive the car every day or the battery will be flat on day 2. Anyone any ideas?

Thanks

[Lily]

@Ajcar welcome to the RAC Forum. 😎

Well, it sounds like something is slowly draining the battery when the car is off.

Maybe the alarm system, some interior light staying on or a dashcam wired incorrectly. Also, it could be the alternator or faulty wiring, hard to tell without having a look.

My recommendation would be to check the following things before going back to (another) garage:

• Are any lights staying on? (especially boot)
• Any aftermarket tech installed?
• Does the battery warning light ever come on?
• Any unusual noises/electrical behaviour?
  
  

We have some great car experts here in the Community, hopefully they will be able to suggest more causes and possible solutions.

We also have an excellent article about batteries here. Please take a look, there are other things there you might find useful.

[olduser]

It looks as though you are unable to to check for parasitic drain (un expected power loss while car is not running) on the battery.
In view of that, take it to an Auto Electrician, tell him the history and they should sort the problem out, garages are not good with electrical faults.
You should find one in Yellow pages or Google it.

If the car is doing short runs all the time, Invest in a Smart Battery charger, and use it about once a month.

[NMNeil]

Buy a cheap multimeter.
Check the battery resting voltage with the engine off and nothing electrical switched on, 12.6 is fully charged, 12.2 it's partially discharged and anything below 10 volts it's probably dead.
Start the engine and rev it to about 1200 rpm with nothing switched on. If the voltage is below 13.5 or so, it's not charging properly, if it's over 15 volts it's being overcharged and it has a faulty regulator.
Put the meter onto AC volts and set the engine to around 2000 rpm with everything switched on; lights, wipers, blower motor, heated screen etc. Measure across the battery terminals and if you get a reading of 0.5 volts or more (AC setting remember), the alternator has bad diode(s) and will slowly drain the battery as you describe.
Don't guess, diagnose step by step.

[Lily]

@Ajcar hey any luck with the Ford Ka? Have you guys found the reason behind some many drained batteries?