Do I Need a New Car Battery?

Ljanetfond on 29/04/2020 - 15:24
Last edited 29/04/2020 - 15:31 by 2 other users

Hi I don’t know much about cars please help!

My battery died two weeks ago, as in the car would click not start. I charged it and took for a drive and it was fine. I haven’t driven it again for about 4 days and even then was a short trip thanks to lockdown! Now it’s gone again.

With a multimeter it tests 12.6V before charging. I’ve put it on the charger again now. Is this a sign I need a new battery or is it just from not starting/driving enough? If it was the alternator it wouldn’t start up after charging- correct??? Because it seems to start up fine once I’ve charged it.

Would appreciate any advice thanks so much! It’s a Mitsubishi ASX and I can’t recall how old the battery is and can’t find any kind of date stamp? I have a feeling it’s about 3 years old but I do very little driving usually as in less than 7,000km a year - not sure if that makes a difference.

Automotive Car Battery Rechargeable Battery

Comments

  • Nugs on 29/04/2020 - 15:27

    Once running again, put multimeter across battery terminals. It should read around 14v if alternater is working.

    • janetfond on 29/04/2020 - 15:31

      Thanks :) so if it does and the alternator is ok does it mean everything is probably ok and it is just from lack of driving ?

      • Nugs on 29/04/2020 - 17:14

        a battery shouldn't lose charge in 3 or 4 weeks, let alone 2.
        if alternator is functioning OK (at around 14v charging), then battery is likely culprit.
        May also have a parasitic drain where there is 'something' slowly draining the battery i.e. aftermarket immobiliser or other always on device that is slowly draining the battery.
        does the battery have a health indicator on it? there will be a sticker that shows green OK, and a combination of red/black/clear if otherwise.
        an example
        https://www.bing.com/images/search?view=detailV2&id=7C1AE649…

  • janetfond on 29/04/2020 - 15:29

    PS have cleaned terminals no corrosion

  • Mrbean007 on 29/04/2020 - 15:29
    -7

    Or just disconnect negative while car is running if it stalls alternater needs replacing.

    • janetfond on 29/04/2020 - 15:32

      Oh ok will do that too :)

      • Euphemistic on 29/04/2020 - 17:28

        I’d you have a volt meter, indicated by already knowing the resting voltage of the battery, a better way to check is to test the voltage at the battery while the car is running. While unlikely, disconnecting the negative while running might mess with electronics in the car.

      • Hithere on 29/04/2020 - 17:57
        +1

        disconnect negative while car is running

        PLEASE! don't attempt this OP.

        You'll stand a good chance of frying some of the vehicle's major electronics.

        It was OK to do this in the old generator days but not with modern vehicles.

  • Caped Baldy on 29/04/2020 - 15:34
    -2

    Alternator probably needs replacement. You may have something running which is draining it.

  • rompastompa on 29/04/2020 - 15:37

    Batteries generally last 3-5 years, so likely culprit.

    You may also find that there's something drawing power when the car is off, which you haven't noticed before. Some after market stereo head units can still be powered (keeping settings etc).

    • janetfond on 29/04/2020 - 15:42

      Thanks I only have the stereo that came with the car and nothing else is attached. If something was draining the battery would it still test 12.6V at rest ?

      • ssquid on 29/04/2020 - 19:09

        The resting voltage doesn't mean much, it has to be really flat to drop below 12V.

        There's a bunch of "ordinary" stuff in a modern car that can malfunction and drain a battery like power windows, door locks, courtesy lights… there's even a relay whose purpose is to disable the heater fan while the car is attempting to start, so if it gets stuck on somehow it can be pretty hard to detect.

  • apsilon on 29/04/2020 - 15:47

    If the battery is at 12.6 and stays around that while cranking and the car won't start, you've got a problem other than the battery. 12.6v is plenty to start a car. On the other hand if it's 12.6 and drops when you try and start then yeah, battery.

    What happens when you try and start? Does it turn over, nothing?

    • janetfond on 29/04/2020 - 16:25

      Yeh it tries to start like a tiny motor attempt and clicking sound but doesn’t start - I have it on the charger now

  • aoeueoa on 29/04/2020 - 15:49
    +2

    Your battery can show 12.6 but still won't be able to deliver the cranking amps which diminish over time. Having the battery tested for cranking amps is the best way to know.

    Are you in Sydney by chance?

  • quog on 29/04/2020 - 16:25
    +1

    Sounds like a cell has collapsed.

    If you are in NRMA / RACV /RACQ etc etc, call them out (their battery people) and get them to do their test as their mutltimeter tells you the alternator levels. You are under no obligation to buy their battery, but the convenience is a plus.

  • janetfond on 29/04/2020 - 16:30

    I’d be quite surprised if it was my alternator as the car has only done 47,000 km!

    • Mechz on 29/04/2020 - 22:02

      You never know, parts can fail early.

  • brendanm on 29/04/2020 - 16:53

    Put multimeter on battery terminals. Attempt to crank motor, note voltage. If it drops below 10 or so, battery is gone. When you get a new battery, put multimeter on battery terminals with car running to check alternator, should be 14ish volts.

  • Adz81 on 29/04/2020 - 17:07

    Less than 7,000km's per year… I'm a little envious of that… My average for the last 5 years has been something like 35,000kms per year 😳

    • Adz81 on 29/04/2020 - 17:12

      Also, if you have a key fob (ie: not a key as such, you just keep it in your pocket and press a button to start), be wary of where you keep your fob in relation to the vehicle when not being used. I was told that if the key is within range of the vehicle, the vehicle remains in a "ready state" to start and that can drain the battery a little quicker. I may have been led up the garden path on that, but in a different time, when I wasn't driving the car as much, I kept the key up the other end of the house from where the car was parked and had no dramas leaving the car parked for two weeks at a time.

  • Euphemistic on 29/04/2020 - 17:32

    Given the car doesn’t do many kms I wouldn’t be surprised if the battery is kaput. Short trips, irregular charging are not ideal for a car battery.

    Charge the battery, go for a drive, 10-15mins should do (but don’t stop until you get home) and try to restart the car a couple of minutes after stopping.

    Alternatively, drive to a battery shop and ask them to test the battery. If dud, buy a new one.

    Test thw voltage while the car is running. If it is higher than the voltage of the battery before you started the car the alternator is fine.

  • Cluster on 29/04/2020 - 17:52

    There should be a date code on your battery to let you know when it was manufactured. The codes vary by manufacturer, so try searching your battery brand and "how to read date code". Car batteries age and deteriorate, including when they're not used. As a rule of thumb car batteries should be replaced every 5 years.

  • [Deactivated] on 29/04/2020 - 22:42
    +1

    Take it to super cheap and ask for a load test. Voltage isn’t what you want when starting, cold cranking amps is the key. Originally the battery might have 600CCA, but through degradation and inactivity it might be down to 200 and unable to turn the engine over.

    • slick7 on 01/05/2020 - 10:08

      My NRMA replacement battery on one of my cars died almost exactly on 3 year mark and the voltage was showing fine. I actually have a plugin USB charger/adapter with voltage display in the cabin from an older car I rarely used. Took it to Battery World and the CCA reading came up as 55% of the original capacity. The guy there was surprised I managed to start it with such low CCA (diesels tend to need a little more)

  • duluxe2000 on 30/04/2020 - 14:06

    Just buy a new one or wait for the next deal on batteries.

    You can use your old one until it dies completely but it's not worth the trouble (e.g. it dies when you're outside).

    I used to call roadside assistance 3-4 times because of my old battery. Then I decided that was enough and bought a new one, worth every cent although I bought it at full price (should have bought one when there is a deal)

  • brad1-8tsi on 30/04/2020 - 16:02

    Where in Sydney are you. If near Erskineville I can have a look and also throw a charger on the battery to give it a proper charge.

  • janetfond on 30/04/2020 - 17:10

    Wow thanks everyone for all the feedback I really wasn’t expecting so much help and it’s great to know there are still good people in their world!! It is actually looking like it’s the spark plugs and I remember now a mechanic told me two years ago that one of them was on its last legs. I could actually do this myself but it may have worn the battery down and that may need replacing too so I’ll leave it all to the experts. The stubborn single mum DIY’er in me had me believing I could sort it out - but I have learnt a lot so that’s a good thing. So many women don’t know the first thing about cars.
    Anyone had experience with the mobile mechanics? Or maybe Kmart ryde and auto..

    • ssquid on 30/04/2020 - 19:58

      Bad spark plug(s) wouldn't run the battery down. They could make the car difficult to start, but not in the way you describe (the light ticking sound).

      • janetfond on 07/05/2020 - 14:39

        Thanks yep you’re right but the sparks plug are bad and I read that if they’re gone or almost gone this can be the cause of the battery wearing down over time so likely the spark plugs need replacing but also I’ll probably need a new battery too.
        With plenty of time on my hands I stupidly and stubbornly decided to do the spark plugs myself in the first instance. I really just wanted to challenge myself. Ugh! Never again. I bought the spark plugs, a nice new socket set with ratchet (I needed this anyway), I managed to get the coils disconnected and out. So far I’ve managed to get two of the spark plugs out (definitely well and truly had it) but the last two just won’t budge.
        I even got the socket stuck in the hole and it took me an entire day to get it out. I’ve tried pulling the spark plugs out with thin pliers but I gather they are still screwed in to the boot even though they feel loose. I’ve tried getting them out with a hose (read online) but the hose is too narrow. I can’t get the ratchet to budge even 1/4 inch either way and the extension wobbles so much it’s hard to know what angle to hold it. Anyway I’ve sprayed some liquid lanolin in overnight and about to try again. I saw a video where a guy hammered the extension bar in and then used the ratchet but this didn’t help me as everything is probably a bit greasy/slippery by now.
        Would love any tips but no criticism! This is a good learning experience lol

        • janetfond on 07/05/2020 - 14:41

          Oh and I also taped the spark plug socket into the extension bar using electrical tape (another YouTube tip!) so I don’t lose the socket in the hole again!

  • StonedWizard on 01/05/2020 - 15:52

    My car all week has struggled to crank but today finally died.

    Any deals out there on batteries at the moment?

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