Does anybody else have the problem that the battery is slowly emptying and needs to be topped up using a battery charger every few months? Is the generator generally too weak, or is there something wrong with my car. Already at the first service (around 27k km) the shop told me that they had hooked up a battery charger since the power level was on the low side. After that I have checked the battery level every now and then, and it has always needed recharging.

 

The car does mostly do short runs (5 min) 2-4 times a day, but at least once a week I run drive a little longer (2x ~30mins) A-road stretch as well. I have even tried to run on lower gears to get higher RPMs, but it seems that it is still not enough to charge the battery. The car will turn 3 years by end April, so is this something I should take up with the dealer as I plan to keep the car for at least another year.

Is it possible the lamp in the glovebox is not switching off and discharging the battery?  (A known problem)

 

Check the glovebox is not hot from the heat of the lamp.

Hmm... I think I have replaced the bulb in the glove box with a LED, but I will check this. Thanks for the tip

That shouldn't be happening.

 

I have the glovebox light problem.  It definitely goes out when the car is locked.  I checked by putting a video camera in the glovebox!  I took the bulb out anyway until I can get it fixed.

 

Take it to a vehicle electrician to do a battery drainage check.  They will shut everything down and check the current being drawn from the battery - it should be no more than a few 10's of milli-amps being drawn by the clock, anti-theft alarm and other bits of electronics.

 

Maybe you have a bad battery that just doesn't hold its charge.  They normally last 5 yrs or more but some do fail earlier.

I am leaning towards faulty battery as well. Not least since I charged it yesterday for over 3 hours, and the charge level is still alarmingly low...

 

On the other hand, it can't be that faulty, because the car has worked properly for 3 years now.

The story continues. I am now able to monitor the current from inside the car using a BT OBD-II dongle and Torque app on android, and this is what I get:

 

When I crank the starter engine, the current drops as low as 8,5 V (I think this is low, but  I am not sure), and with the engine shut of the battery has less 12 V of current. This reading was taken right after  ~20 mins of driving at 80-100 kph.

When the engine is running I see between 13,8 and 14,5 volts, and it is fluctuating quite a lot, even with cruise control enabled on flat A-roads at 100 kph.

Today I will recharge the battery all day using an external battery charger that outputs 5,5 A, and I will check again what the battery says in the coming days. That should help me find out if the battery is bad (the battery does not hold charge) of if the generator is bad (battery show higher voltage first, but then drops with time).

I think you have already gathered enough information to be able to convince your dealer there is a problem.

You originally reported the problem at the car's first service, but your dealer failed to find the cause of the problem.

Your car is less than three years old and still under warranty, and it is up to your dealer to put it right.

Hope it all gets sorted.

The first things I would check are the battery, the battery cables and the control wires that go to the small plug on the alternator.

The battery seems to be dead. 6 hours of charging has brought the current up to just under 12 V. New battery (and installation) ordered from dealer, and then we will discuss who will pay... Installation after one week, hopefully the battery lifes on so long.

 

Robjon: actually it was the other way around; the service guy had noticed that the battery charge was low, and they had charged the battery during the day and informed me about this when I picked up the car. I do not think they did any other investigations though.

Case closed; battery replaced at dealers'.

I ended up paying the full sum myself - I had no proof that the battery had been faulty, and it turned out that it is very common that batteries are not fully charged (and therefore degrade faster) in the area I live in with many fairly short runs or mostly standing in traffic. Nearly all serviced cars have their batteries recharged during the service,