hyundai coupe 2.0 2006.

Battery was fine for few years until it died few months ago. Replaced battery and it died within a month. Replaced that battery with same brand and it died within 2 weeks. Replaced that battery with a more powerful one and that seems to be dying too(im noticing car needs more crank, cabin top lights, dashboard lights, time light flicker on ocassion etc.

everytime i too it to shop they told me the battery was dead but the alternator was fine from their test.

Do you know what might be killing my batteries? I dont have a multimeter at the moment to test but should I take some specific fuses out and see how it runs?

I noticed the stereo(i think its aftermarket with lcd screen) goes off sometimes so i wondered if thats something to do with it. i can see there is a audio fuse which ill try and remove however i also see theres a fuse called 'lp room' i think and it also relates to audio. should i remove that aswell? problem is that i think that fuse is for other things besides audio.

Any other suggestions what I should look at?


  • The first thing that comes to my mind is the voltage regulator which is almost always built in to the alternator today.
    – jwh20
    Commented Oct 7, 2019 at 1:37
  • @jwh20 Does this mean the alternator needs to be replaced? Is it something that the shops alternator tests would miss? How can one diagnose this? Commented Oct 7, 2019 at 1:55
  • If you dont have a multimeter the next best thing is to take your car to your local parts store and ask to borrow theirs, most of the time they'll loan it to you for free if you stay in the parking lot.
    – user38183
    Commented Oct 7, 2019 at 2:17
  • There is a difference between a battery dying and draining. Is the car "killing batteries" or simply not recharging properly? Are you being had over by the battery shop? Commented Oct 7, 2019 at 9:07
  • @hellomoto I've edited your comment for clarity and deleted the extended discussion that didn't add anything to the question.
    – Nick C
    Commented Oct 7, 2019 at 12:02

2 Answers 2


Check things like the glove box light etc...

But even a coil voltmeter can be used to detect a drain - connect it between the battery terminal and the battery cable and it will show voltage. Then disconnect or remove every fuse in turn until the drain stops ie the voltmeter goes to zero. You have then located the circuit that is at fault. Next break the circuit down to find the culprit - it's like a detective story - find and follow the clues... But never easy...


Loose connections can cause batteries to die as well as cause charging problems which in turn cause batteries to die so check for loose connections on battery terminals, fusebox cables, alternator etc.

Like Solar Mike says check for things that maybe draining the battery such as a glove box light.

parasitic draw may be draining your batteries. If you dont have a multimeter go get one as it will be far easier to help diagnose problems then to just remove fuses at random and see what happens. It's very easy to test for parasitic draw. switch engine off. With a multimeter put red prob in amps port as that is what you will be testing for. set dial to 20 amps. Disconnect negative battery terminal. connect red probe from multimeter to negative battery terminal. connect black probe of multimeter to negative battery terminal cable. Multimeter will show how many amps are being drawn from which you can deduce if there is a parasitic draw problem and if so you will have to go about removing fuses to find which one reduces the draw.

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