Brand new battery showing 12.38 at terminals and car trouble

Brand new battery showing 12.38 at terminals and car trouble

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markander46

Original Poster:

5 posts

56 months

Friday 16th August 2019
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Hi Folks,

I'd been having what I presume to be battery trouble with my trusty old yaris. I went to drive it one day last week and the car wouldn't start. All the lights, radio, fan blower etc. worked, but the car wouldn't turn over. There was no clicking noises or even any lazy attempt by the car to turn over.

I imagined it might be the battery as I'd flattened it the week before by leaving an interior light on overnight, and maybe since that occured I hadn't done enough miles to recharge it properly.

A friend was good enough to come down and give me a jump again after I'd previously flattened it, and so this time I gave it a good run for an hour to recharge the battery. The next day the car started no problem. I had a journey of about twenty minutes to do, so off I went, upon returning to the car ten minutes later the car wouldn't start again, silence upon turning the key. I was on a hill, so managed to bump it. As you can imagine by now I'm starting to think the battery is goosed.

I was fortunate enough to get a jump again, but this time the friend brought a voltmeter. Before jumping it he tested the battery at the terminals. It was showing 12.4. After he jumped the car he tested the alternator with the voltmeter as he said maybe the alternator was no longer working. The alternator test showed 14.24 under no load, and about 13.78 if i remember correctly under load. He thought the the battery may have a dead cell so suggested a new battery. One thing that perplexed him, was that after he jumped my battery he restarted my car under it's own power while connectiing the voltmeter and the battery only dropped to about 11.40 or near as.

I took my friends advice and ordered a new battery and my own voltmeter. The battery has turned up along with the voltmeter. I tested it myself at the terminals using the voltmeter and it's was showing 12.38. I thought it should show 12.6 or higher? (it's the correct battery for my car) Anyway i fitted it to the car in hope, but yet again, silence upon turning the key. Lights, radio and blower are all working as normal. So have I ordered a duff battery? or is it maybe an electical problem? Should i also jump this new battery? I know of course you can't diagnose my car at your home, but any help on tests i can do would be welcome.

If you're wondering why I haven't took it to a garage, a recent illness has had me give up my job, and the funds just aren't available like they were previously. So I'll need to start learning myself if I'm to fix this.

jet_noise

5,648 posts

182 months

Friday 16th August 2019
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Anything above 12.2 ignition off is a likely healthy battery. Although under load it may give a very different result.
A charging voltage engine running of 13.5-14.4 is normal.

As your starting issue is occurring with both old and new batteries it may be that the issue lies elsewhere.
Although from your description I can entirely understand why you've tried a new one.

When you attempt to start do the dash lights go dim?

Krikkit

26,527 posts

181 months

Friday 16th August 2019
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I suspect a dodgy starter from the sounds of it. The battery sounds like it was a bit weak, so it's not a total waste getting a new one.

banjowilly

853 posts

58 months

Friday 16th August 2019
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Had very similar problem recently. On mine it was a loose engine ground strap. Check those first - it's cheaper than buying anything.

markander46

Original Poster:

5 posts

56 months

Friday 16th August 2019
quotequote all
Hi all,

Thanks for the replies!

Jet_Noise: thanks for that piece of info, i'll go try that now. I'll not be able to see my front headlights, but I assume by putting the interior lights on, they would dim too upon trying to start as well.

Krikkit: I'm trying to do a bit of reading about this, and I keep seeing starting motor come up too. (that and fuses) I'll go see where to locate the starter motor now as well.

Banjowilly: Loose engine earth strap. as you can probably tell by my intial post i'm a total novice at this, but i'll see if i can go and locate this earth strap too.

Thanks again all for the replies. You can all probably tell by now that engine mechanics and electrics are new to me, but we all gotta learn sometime right smile

Thanks to to whoever moved this to the correct part of the forum.




banjowilly

853 posts

58 months

Friday 16th August 2019
quotequote all
On the ground straps, you're looking for two normally. One will be the thick black wire from the negative battery terminal that will bolt onto the chassis nearby & there will be another somewhere that will bolt from the chassis to somewhere on the engine or gearbox, possibly to an engine mount. It's hard to miss as it will be the thickest wire in the engine bay.

Since you have fans, lights etc. but no cranking AND a brand new battery, it's my strong suspicion you're not earthing but that's not to discount what others are saying, just that it's the logical place to start & is a much better idea than randomly throwing parts at it & hoping for the best.

jet_noise

5,648 posts

182 months

Friday 16th August 2019
quotequote all
If the starter is taking current, the battery is poor and/or there's a general poor connection then the lights'll dim.
If the lights do not dim then the starter is not being asked to turn, there's a local to the starter (e.g. block earth strap as others have suggested) poor connection or the starter itself is bust.
All IMHO

If you can get your meter to the starter motor terminals then some of those things could be eliminated.

Granny egg sucking tutorial:
Be careful as these have a lot of oomph and can be permanently powered. Also make sure your test leads, you and your clothing avoid anything which is or will rotate.
Other usual precautions apply - out of gear (obvs!), handbrake on, chock wheels if you can't. Axle stands (or similar) as well as jack especially if it's a hydraulic one if getting underneath.



paintman

7,687 posts

190 months

Friday 16th August 2019
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If you had flattened the battery a run of an hour or another 20 minute run will make little difference to the charge.
You should have fully charged the battery with a battery charger.
Alternators are not designed to recharge flat batteries: https://www.optimabatteries.com/en-us/experience/2...

Assuming your new battery is good AND fully charged you MAY have an earthing issue OR a faulty starter motor - amongst other possibles. One way of ruling out the earth issue is to connect a good quality jump lead from the battery earth terminal to a good clean metal point on the engine & try starting to see it if makes any difference.
Worth cleaning the battery terminals & making sure the leads are tight.

GTVOX

66 posts

62 months

Sunday 18th August 2019
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Also you can check the car's earths and grounding by running a jump lead from the earth terminal to the engine block or gearbox. Sometimes earth straps can corrode internally.

E-bmw

9,217 posts

152 months

Sunday 18th August 2019
quotequote all
GTVOX said:
Also you can check the car's earths and grounding by running a jump lead from the earth terminal to the engine block or gearbox. Sometimes earth straps can corrode internally.
I think you will find that is what the poster immediately above you suggested. wink

markander46

Original Poster:

5 posts

56 months

Sunday 18th August 2019
quotequote all
Hi all,

Thanks very much for the replies, and sorry for my late reply.

I'll try to answer questions asked and what I've managed to check.

So upon turning the key the lights don't dim, so one of the replies mentioned the starter may not being asked to turn. I found the starter motor at the back of the engine, unfortunately it is a complete nightmare to get to. I can barely see it, but managed to get a small look at it by using my phones light and recording, it doesn't look to be in great shape, in fact there appears to be a lot of rust about.

I did mange to do a ground test someone showed on youtube by connectiong the black probe of my multilmeter to the megative battery terminal, and the red probe to the starter motor body. I got the continuity beeping noise from the multimeter, but not at all points I put it on, but there was loads of heavy dust on the starter. I can't actually see the power feed to the starter as it's obscured.

Ive also tested all the fuses in the box in the bonnet, three that I read are responsible for starting, I visually inspected. The rest I used the continuity function on the multimeter and they all appear to be fine.

I got a shot of a battery charger from a friend and the orignal battery charged up no problem and appears to be good. That and having a new battery that's better than my old one, I think I ca rule out a battery problem now.

My friend also tried to jump my car with his jeep, but it wouldn't jump. I also noticed after my friend left and it was a bit quieter that I think my fuel pump is primimg..There's a noise coming from the back seats. I also noticed a noise under the bonnet, like whirring noise coming from either the back of where my ignition key goes or maybe a bit to the rright of it.

What I'll try now:

I'll try the jump lead from the negative to an area on the engine.

I've found another batch of fuses under the glove compartment, i'll test them for continuity.

I'll try get better access to the starter and find out how I can do more tests on that. Thanks for the saftey tips by the way smile

I'll try find out what this whirring noise is responsible for, or what it should be doing.

And, can someone please tell me how to test the grounds around the engine using a multimeter Should I be on ohms or volts? black probe to ground point and red probe on battery terminal or other way around?

Thanks again for the replies, it's appreciated smile

Edited to say I'll make sure the connectors are spotless too.

E-bmw

9,217 posts

152 months

Sunday 18th August 2019
quotequote all
markander46 said:
And, can someone please tell me how to test the grounds around the engine using a multimeter Should I be on ohms or volts? black probe to ground point and red probe on battery terminal or other way around?

.
The best way is to just bypass the whole issue (if it is one you will know with this simple test) Get a jump lead and connect 1 end to the battery black terminal if it is in the engine bay (a main bare metal chassis bolt if not) and the other end to bare metal on the engine.

If that makes a difference then you have likely found that your engine/chassis earth is stuffed.

Penelope Stopit

11,209 posts

109 months

Sunday 18th August 2019
quotequote all
Ok, in reading through this topic I have come to the conclusion that you do have access to a multimeter, are new to electrical fault finding and your head is now spinning due to so much help that differs a touch here and there

E-bmw has posted you good info about proving if the battery to engine earth is good or not......but there is a catch........

Most DIY jump leads are not good enough (garbage really) for jump starting a car never mind using them for testing things out

If you have very good thick cabled jump leads you can go ahead and follow the above post from E-bmw

If you are not sure about how good the jump leads are you can.......................

Set meter to 20 volts DC or the closest you can get to above 13 volts

Don't be concerned about which way to connect your voltmeter leads as a multimeter will give a reading of + or - depending upon which way it's connected

With the car in neutral and someone assisting you...........connect the voltmeter/multimeter black cable to the battery negative and the red cable to a cleaned area of the engine block (it doesn't matter if you connect black and red the other way around)

Now ask your assistant to turn the key into the crank position, while in the crank position the voltmeter/multimeter should not read more than 0.25 volts

You can carry out the same test on the main positive cable from battery to starter motor and the voltmeter/multimeter should not read more than 0.75 volts

You can check the voltage at the thin cable that operates the starter solenoid if you can get to it.........Connect black cable of voltmeter/multimeter to battery negative and the red voltmeter/multimeter cable to the thinner cable at the starter solenoid that connects to a spade or eyelet terminal (this is the cable that comes from the ignition switch to operate the starter solenoid), the meter reading should be approximately 11.8 volts or above when the key is turned to the start position

Have fun, good luck in finding the fault

  • Keep hands well clear of the engine**
Edited by Penelope Stopit on Sunday 18th August 21:37

GTVOX

66 posts

62 months

Monday 19th August 2019
quotequote all
E-bmw said:
The best way is to just bypass the whole issue (if it is one you will know with this simple test) Get a jump lead and connect 1 end to the battery black terminal if it is in the engine bay (a main bare metal chassis bolt if not) and the other end to bare metal on the engine.

If that makes a difference then you have likely found that your engine/chassis earth is stuffed.
I think that exactly what I said

E-bmw

9,217 posts

152 months

Monday 19th August 2019
quotequote all
Correct, I only reiterated it for the OP as he seemed to have missed what you were telling him how to prove. wink

markander46

Original Poster:

5 posts

56 months

Tuesday 20th August 2019
quotequote all
Thanks for the advice on the jumplead to a clean position on the battery.

This didn't make a difference when trying to crank. I found a clean spot on the engine, and also a bracket on the alternator to try from, but alas. However, as mentioned by penelope my jump leads might be a bit on the poor side.

Screenshot_2019-08-20-01-31-04-538_com.miui.gallery by Mark Anders, on Flickr

I also had a pal coming to help whilst I tested the battery and possibly the starter (though it's a nightmare to get to, can't even see it properly) but he has phoned to say he can't make it now, and he says "it's raining" So that'll need to be tomorrow now.

Access to starter, the video below doesn't show the difficulty getting to it, that was me with arm in back of engine. I may have to get it on stands from underneath.

access to starter by Mark Anders, on Flickr

Also I mentioned the whirring noise after trying to crank,maybe from ignition? That's where it sounds like it's coming from when you're near it. Hopefully someone may recognize this noise.


whirring noise from ignition sytem by Mark Anders, on Flickr

I was also surprised to see the new battery down at 12.19 volts as I was about to lock the car, maybe from me trying to crank and capture that noise? The car hasn't started the car, so the battery has done pretty much nothing, it was only fitted a few days ago.

IMG_20190820_170903[1] by Mark Anders, on Flickr

Thanks for all the replies again! I thought I'd try add a few pictures and videos rather than descriptions this time, so hopefully these embeds work smile

Edited by markander46 on Tuesday 20th August 19:38

GTVOX

66 posts

62 months

Wednesday 21st August 2019
quotequote all
You"ve eliminated the easier/cheaper stuff so as posted right at the beginning by others it's pointing to the starter. You need to take it off and test it. The whirring noise (which I couldn't hear) is that it's probably not engaging.

E-bmw

9,217 posts

152 months

Wednesday 21st August 2019
quotequote all
1. That jump lead should have been engine to car chassis/body, not starter to engine, they are already bolted together.

2. The leads you show are fine to test with for now.

3. 12.19 volts is flat. A car battery is actually 6 x 2.1 volt cells, and should measure 12.6 volts fully charged, for every 0.1 volt down a rule of thumb is it has lost 20% of its charge, so yours is around 20% charged.

markander46

Original Poster:

5 posts

56 months

Wednesday 21st August 2019
quotequote all
Hi,

GTVOX, yes I'll try get the starter off today. I have a halfords ratchet set with extensions, so that should give me more reach, thanks.

E-bmw, Sorry I probably didn't word my reply right in the previous post. I actually did connect one end of the jump lead to the negative battery terminal, and the other end to a clean bit of metal on the engine as helpfully suggested by you in a previous post, thanks.

Yeah, the bit about the battery voltage was just an observation by me. It's a new battery (exide 50 amp, 450cc, stronger than my old battery) only three days fitted and already it's flat. I couldn't see how it was flat. as it's literally done nothing, but then again I don't know a lot about batteries.

I put back in my orginal battery to do tests to after I trickle charged it, as i now know there was nothing wrong with my orignal battery (Bosch silver) my problem lies elsewhere. Thanks again.

E-bmw

9,217 posts

152 months

Wednesday 21st August 2019
quotequote all
markander46 said:
E-bmw, Sorry I probably didn't word my reply right in the previous post. I actually did connect one end of the jump lead to the negative battery terminal, and the other end to a clean bit of metal on the engine as helpfully suggested by you in a previous post, thanks.

Yeah, the bit about the battery voltage was just an observation by me. It's a new battery (exide 50 amp, 450cc, stronger than my old battery) only three days fitted and already it's flat. I couldn't see how it was flat. as it's literally done nothing, but then again I don't know a lot about batteries.
I did wonder if that was what you actually meant, just thought to mention it.

On the battery point, a few cranks without a good charge will take a lot out of a battery, as you have found out.

No probs.