OK apologies because this is a bit of a saga, I’ve tried to include all the information I can think of.

Recently I have been having a sporadic pair of warning lights pop up together  for the bulb monitoring (all bulbs are fine) and the immobilizer key (again haven't noticed an issue in this area.) . It happens randomly and they come on together. If it comes on it happens when you depress the brake and after a while it disappears.

Have replaced the brake switch – did not solve the problem. Seems to occur less but still occurs

Recently the battery was draining and not starting when I came to use it. I don’t use the car much, at most once and week but usually once a fortnight or so. Once the battery was charged (or jumped) it would start and drive but would then be flat again a few days later.

So, I decided to replace the battery with a new one assuming it was the problem (haven’t had a new battery in 8 years and  the car doesn’t get used much as mentioned so thought that was best)

Car started and drove fine and all was fine the first use.

A week later I tried to start the car again it and it wouldn’t start. I had been fiddling with some of the inside lights and noticed that two of the car door inside lights were on in the rear. So, I switched them off and charged the battery with a 4 amp trickle charger for about 7 hours. Car started, drove it about 5 miles.

Next day I went to drive it again and it wouldn’t start. (at this point we also had a problem with the brakes – there was a tear in one of the servo pipes. This was sealed up (waiting for a replacement pipe) and the brakes are now fine so I think unrelated…but have mentioned just in case) I bump started the car and left the engine running for about 45 mins to an hour. Turned it off and tried to start it straight away – which it would. Then turned the engine off and tried to start again and it would not start. As if totally flat battery again.

 

If anyone has any thoughts I’d appreciated it. I’ve checked all main fuses which seem ok. I have a multimeter so can test the battery (and the old one) but not sure the best way to test. If anyone has any thoughts?! Thanks!

Start with this free, easy check: https://www.briskoda.net/forums/topic/401778-battery-light-and-associated-problems/

 

Thanks Wino - that looks like a great starting point! Thanks so much. I'll take a look and report back after work. 

@hubsandspokes1987 My immediate thought too. Easiest first check. Does the battery light come on when you switch the ignition on but don't start the engine?

Hi both! Just an update. With the key in the first position the battery light does come on and stays on. Can’t test what happens on starting (yet) as I’m having to charge it in order to start it. 
 

I had  a look at the cables at the alternator end (i think!) see the photo. Seem fine at this point.  But not the other end - I guess I need to root around I’m under the engine to check the other end? 
 

can I put a multi meter at the alternator end and check the reading? And is there any point if the battery light is on in the dash? Lastly would the battery need to be fully charged for that to be relevant? 
 

thanks so much again!

6 minutes ago, hubsandspokes1987 said:

is there any point if the battery light is on in the dash?

Nope. You've just ruled out one common charging system fault.

 

Next thing to do (when you've finished charging the battery) is to measure the voltage across the battery terminals with engine running at idle, with no major current consumers switched on in the cabin.

Ok, thanks! I won't chase that thread any further then. 👍 I'll report back on the voltage once the battery is charged. Probably not today with this miniscule charger I have! 

No rush, long slow charges are best.

 

The test I've just suggested is to establish if the alternator is actually generating, and it should also indicate if there are major voltage drops in the cabling/connections between alternator and battery.

May as well check the voltage with one or two consumers switched on, while you're at it. Say headlights and cabin fan on max.

If your multimeter does current measurements you could check the overall quiescent current too:

 

https://www.briskoda.net/forums/topic/495243-quick-and-dirty-parasitic-current-measurement/

 

Hi Wino! Thanks for the great 'how to' on the amps. Sadly I couldn't get on the forum today (I think it was undergoing maintenance) so I couldn't get to your instructions. I did manage to get some voltage measurements on the battery so I've put these here in case it gives any enlightenment! 

So yesterday I put it on the 4 amp trickle charger as we mentioned. After around 1.5 hours it was saying fully charged. Did not try to start it (not time last night and I wanted to check voltage at full charge before trying to start it)

This evening at around 6pm I read the  voltage  – read at 10.56 V- this was with the engine off as it wasn't starting at this point. When I plugged it back into the charger it was no longer reading fully charged.

Left it to charge again and went back to check and according to the charger it was again fully charged in around 30 minutes. Voltage read 13.10V. The car still would not start. I took the battery out and read the voltage again at 11.49 (after trying and failing to start a couple of times.)

 

For interest I measured the charge on the old battery I still had and it was 12.32. I put it back on charge and after half an hour or so it was reading fully charged. So for interest I put the old battery back in and the car started straight away. Reading across the battery while car was running 14.4v. Turned engine off – waited 5 mins and packed up and checked again and would start…!! So i'm pretty lost. I'll check again in the morning whether the old battery has drained as well. Tomorrow or over the weekend I can try your amp check now I can access the instructions again 🙂

 

 

You're not charging those batteries anywhere near long enough, leave it on charge overnight.

Keep trying to charge the newer battery, maybe after a lot of attempts it'll actually start charging normally, which it doesn't seem to be right now.

 

The old battery certainly seems in better shape, as judged by readings and its ability to start the car.

The alternator seems healthy so it does now look as though a battery drain is likely to be found when you get to that.

Checking the voltage on the installed battery in the morning should tell a tale on its own.

As you have reason to expect a higher-than-normal reading, it's probably prudent to set the meter to whatever its highest range of Amps DC is, in case it is a really high value that might blow the fuse of a lower (milliamps or hundreds of) range. 

5 minutes ago, sepulchrave said:

You're not charging those batteries anywhere near long enough, leave it on charge overnight.

Thanks Sepulchrave - I know it's very short. But have used this charger before during this issue and have been leaving the batteries to charge for 8+ hours and it's never given me a 'full' reading so far. I have only stopped charging after this amount of time in this instance because the charger is reading as fully charged. But if you guys thinks it's ok (and advisable) to leave it to keep charging I'm happy to take your advice and leave it longer 👍

Just now, hubsandspokes1987 said:

Thanks Sepulchrave - I know it's very short. But have used this charger before during this issue and have been leaving the batteries to charge for 8+ hours and it's never given me a 'full' reading so far. I have only stopped charging after this amount of time in this instance because the charger is reading as fully charged. But if you guys thinks it's ok (and advisable) to leave it to keep charging I'm happy to take your advice and leave it longer 👍

no idea why this photo is right in the middle of the comment! Apologies. 

 

7 minutes ago, Wino said:

Keep trying to charge the newer battery, maybe after a lot of attempts it'll actually start charging normally, which it doesn't seem to be right now.

 

The old battery certainly seems in better shape, as judged by readings and its ability to start the car.

The alternator seems healthy so it does now look as though a battery drain is likely to be found when you get to that.

Checking the voltage on the installed battery in the morning should tell a tale on its own.

As you have reason to expect a higher-than-normal reading, it's probably prudent to set the meter to whatever its highest range of Amps DC is, in case it is a really high value that might blow the fuse of a lower (milliamps or hundreds of) range. 

OK good shout I'll try again over the weekend to charge the battery properly  as I've never got to full charge before. Do you think there's  a chance that the 'new' battery is a dud? I'll check the voltage on the old battery tomorrow and report back . 

In terms of finding a drain I would imagine I'd read the amps from the battery with nothing on (after leaving the car to sit) and take fuses out one and a time and see if the amperage drops? 

Thanks again for all the help!

A current drain that takes any battery to a very low voltage will rapidly cause permanent damage unfortunately, so it may not be the battery's fault.

 

Read the how-to I've linked to for overall current drain (and I'll show you another as follow up if you do find a high overall reading).

 

Newer cars with lots of electronic modules need different, more patient approaches than older simpler cars, to effectively pin down the real problem areas.  Just pulling fuses can cause things which should be asleep to wake up due to communications interconnection, giving confusing results.

Edited 23 September, 20214 yr by Wino

10 minutes ago, Wino said:

A current drain that takes any battery to a very low voltage will rapidly cause permanent damage unfortunately, so it may not be the battery's fault.

 

Read the how-to I've linked to for overall current drain (and I'll show you another as follow up if you do find a high overall reading).

 

Newer cars with lots of electronic modules need different, more patient approaches than older simpler cars, to effectively pin down the real problem areas.  Just pulling fuses can cause things which should be asleep to wake up due to communications interconnection, giving confusing results.

Thanks I'll read the current drain 'how to' and try and investigate that over the weekend!

1 hour ago, hubsandspokes1987 said:

I read the  voltage  – read at 10.56 V

This has me wondering if this battery has a bad cell. Is there any sign of one of the cells "boiling" when it's on charge?

17 minutes ago, KenONeill said:

This has me wondering if this battery has a bad cell. Is there any sign of one of the cells "boiling" when it's on charge?

Ok interesting. I haven't noticed anything but I also haven't been especially looking for that - I guess I'm listening for bubbling or other noise..? Now I've removed the battery from the car this will be easier to check so I'll try charging it tomorrow and listen for any sign of boiling cells. Thanks!

12 hours ago, hubsandspokes1987 said:

I guess I'm listening for bubbling or other noise

That should do it; the one time I saw this the battery was clear-sided and you could both see and hear the gas being evolved when we applied current from a 3AH trickle charger.

Little update. Checked the battery (without the engine running) this morning at it was down slightly at 12.21V. Checked again after work and it was steady at about 12.20.

 

@Wino I tried your parasitic current measurement but not sure I did it right. Locked up the car and locked down the bonnet with a screwdriver and left it for an hour and a half, then read. But the reading when detached was quite hard to work out as it was jumping all over the place. Not sure I did it correctly. It read 0.02mA before disconnection. See attached video!  If it looks unsuccessful I'll try again tomorrow for a smoother technique. 

 

@KenONeillplugged the new battery into the charger today for half an hour or so - couldn't hear it bubbling or fizzing but perhaps it needs to be on longer for that to happen. Plan to try again tomorrow but was off out tonight and didn't want to leave it plugged in unattended. 

4 minutes ago, hubsandspokes1987 said:

couldn't hear it bubbling or fizzing but perhaps it needs to be on longer

No; this is pretty much instantaneous when you turn the charger on. It is a chemical reaction after all.

2 minutes ago, KenONeill said:

No; this is pretty much instantaneous when you turn the charger on. It is a chemical reaction after all.

Ok thanks. Yea that makes sense. Wasn’t sure it it was when it warmed up or something but thank you for confirming! 👍

Your meter's saying mA AC, you need it set to DC. Yellow button?

Have an assistant hold one of the probes, maybe the one straight down on the battery post, then you can focus on keeping the other one on the negative clamp as you lift it away.

43 minutes ago, Wino said:

Your meter's saying mA AC, you need it set to DC. Yellow button?

Have an assistant hold one of the probes, maybe the one straight down on the battery post, then you can focus on keeping the other one on the negative clamp as you lift it away.

Ah what a numpty I am. Will report back again on attempt two. 

Ok update. I think I’m still not getting the amp reading quite right. Probably slipping off the terminal( even with an assistant. ) as it reads 0.00 amps throughout and when I put the negative terminal back down the alarm goes off. I guess I’ll have one more go tomorrow. 
 

as for the ‘new’ battery I thought I’d do some testing out of the car. I charged it up this morning until the charger read full and read the voltage which was 13.12. Then measured it a few times throughout the day obviously got a quick drop after removing the charger as it settled down. And then by 10 hours later.l it had dropped to 10.68. Is that normally with nothing attached to the battery?