I put in a new battery around May this year. Although I got a cheaper one, the battery specs seemed sufficient for the car. I've been driving it every month or so, and the battery often dies and needs jumping. After driving it, it starts once or twice, but then dies again a few days later.

Most recently, I drove it to my garage to do some maintenance. It seemed to start fine on its own, but the next day the battery was dead showing only 10.3V. While doing the maintenance I turned on headlights for about 3 min, but nothing else and didn't start engine.

I bought a supercapacitor jumper which is supposed to use the low voltage in the battery to jump it, but it failed to do so on mine. I then charged the jumper from the plug and jumped the car that way, drove it around for ~30 min, then parked.

On the same occasion I also checked the charging current (14.3V) and fuses (all showed no voltage with car off).

About a week later the battery is once again dead, with 3V. The temperature did drop from about 60F to 30F during this week, although my other car had no issues.

What should I do here?

  • Is the battery just bad and I should replace it (with the same model)?
  • Is the battery model too weak and I need to buy a better battery?
  • Is the fuse method insufficient and I need to look harder for a leak?
  • Is this expected behavior because I drive the car too rarely? Other cars seem to start even after 3 months of not being driven

I initially thought that my car is leaking current when off, but since the fuses showed nothing I assumed that's not the case. I haven't tried putting an ammeter in series with the battery. My next thought is perhaps something is wrong with the battery, and it's only holding a superficial current. But it's suspicious that the old battery was also dying.

1 Answer 1


About a week later the battery is once again dead, with 3V. The temperature did drop from about 60F to 30F during this week, although my other car had no issues.

If this is accurate with just having 3V, the battery is bad and it needs to be replaced. Even if it as you stated at first (10.3vdc), that's not good either. This is usually a sign to me the there may be a dead cell.

Here is my suggestion. This battery should be under warranty seeing as how it is only a few months old. Even el-cheapo batteries should have a free replacement warranty for a certain amount of time. I don't think I've ever seen them less than one year, but who knows. If the warranty exists, get it replaced. I would do this first because it shouldn't cost you any money to do so and you may have just gotten a bad battery. It does happen.

If once replaced it fails again, then I'd go with a main brand replacement. 615CCA should be more than enough for your vehicle. As long as the battery is in the same group size, it's going to be right around this CCA anyways.

Your charging system being at 14.3vdc while running is a good indication it is working as designed.

  • To be clear, both the most recent 3V and the previous 10.3V measurements were done after the car would refuse to start. If I check immediately after the car has been driven for a while and turned off, I tend to see ~12.3V or so.
    – Morce1946
    Commented Nov 6, 2022 at 18:33
  • 1
    @Morce1946 - Which tells me it seems like the battery is bad and is having (as you said) a superficial current. I call this a surface charge. Take it to where you bought it and have them load test it. I'll bet they'll replace it straight out. Commented Nov 6, 2022 at 18:38
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    Thank you! I was also planning to replace it first. The warranty indeed covers it, I've just been procrastinating because it's tedious to take the battery out on this model. I'll try replacing and see how that goes.
    – Morce1946
    Commented Nov 6, 2022 at 18:38

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