My 2002 battery had been quite flat just over a week ago, started with booster pack took it a drive and it was fine for a few days. Left it a day without using and completely flat this time, no display and wouldn't unlook even.

Fitted a new battery (the old one was at least 10yr old as it's been in it as long as I've had the car) on Monday and used for work for the rest of the week and all grand again.

I didn't use it yesterday and when I came out this morning it was totally flat again......no dash display etc.

Something is obviously draining it, are there any common faults go tos?

Thanks in advance.

Had to boost again today totally flat. Mate checked with multimeter, reading 13.8 then when put lights and blower on drops to 12.9, plugged in and showing a charging fault too, reckons alternator the issue, but battery light not coming on, anyone experienced a similar issue?

Edited 8 May8 May by 02VRS

Does the red alternator charge (battery) light illuminate when the ignition is first switched on - then extinguish as soon as the engine starts?

As far as I remember yeah, it definitely doesn’t stay on. That was puzzling mate as would expect to be on if alternator dodgy, or does it not to be totally bingod?

15 hours ago, 02VRS said:

Had to boost again today totally flat. Mate checked with multimeter, reading 13.8 then when put lights and blower on drops to 12.9, plugged in and showing a charging fault too, reckons alternator the issue, but battery light not coming on, anyone experienced a similar issue?

13.8 volts, dropping to 12.9 volts on load appears to be a reasonable output for the alternator - what indication was given for assuming a charging fault?

Just now, Warrior193 said:

13.8 volts, dropping to 12.9 volts on load appears to be a reasonable output for the alternator - what indication was given for assuming a charging fault?

Recheck that the alternator (battery) indicator light operates correctly - on with ignition, extinguishes immediately on engine start.

4 hours ago, Warrior193 said:

13.8 volts, dropping to 12.9 volts on load appears to be a reasonable output for the alternator - what indication was given for assuming a charging fault?

Was plugged into wee computer 👍

4 hours ago, Warrior193 said:

Recheck that the alternator (battery) indicator light operates correctly - on with ignition, extinguishes immediately on engine start.

Yep double checked it’s on with ignition and off when starts

14 minutes ago, 02VRS said:

Was plugged into wee computer 👍

Could you be more specific - was this a dedicated alternator output test device?

Sorry was a snap on computer plugged into the port on dash

Is the infotainment system in the centre of the dash panel the original, factory-fitted system? I have seen reports from a number of owners who have experienced parasitic battery drain issues when after market systems had been installed.

Was totally flat yesterday, jumped it and drove around 20-30mins. Started no worry’s after. Disconnected overnight and started no issues this morning, sat outside work for over 6hours connected and was grand when I was leaving. I’ve not been using aircon or radio past couple days though.

Just now, Warrior193 said:

Is the infotainment system in the centre of the dash panel the original, factory-fitted system? I have seen reports from a number of owners who have experienced parasitic battery drain issues when after market systems had been installed.

It’s all standard. The multi-changer doesn’t work so I disconnected that a few days ago

Latest installment: battery flat Thursday, jumped and took a good drive for 25mins. I’ve used for work and moved about over weekend but disconnected battery at night and it’s been grand. Used aircon on way to work today just to see if it made a difference and when I came out after work (sat for 7hours) it hadn’t enough to turn engine so had to jump it. Wasn’t complete flat.

Couple of thoughts…,

• Would the alt not functioning properly and aircon being on for 10min or so be enough to drain battery a fair bit?

• Would the aircon maybe not be shutting off properly and draining it?

Ignore - misread the post!

Edited 13 May13 May by tetley

24 minutes ago, 02VRS said:

aircon being on for 10min

Air con only works when the engine is working.

Is the new battery the correct one for the car?

Have you bench/mains charged the new battery since it became flat?

Is the new battery faulty?

Alternator / battery warning light ( with the engine running ) won't light up until the volts are very low.

Thanks. AG Falco

Yeah I’d charged the battery, new battery is grand, I’d say the old one is grand too have been charging it as a back up. New one is the exact same as the old one.

If battery light doesn’t come on until really low then alt could be my issue then 👍 charging battery enough until it’s under load then zapping it.

Haven’t had chance to get this looked at again, been disconnecting the battery if parking for more than a few hours and had no issues for around 4weeks! Just an absolute pain .

Regulator on alternator was knackered, £20 odd for a new one, now charging the battery at 14.4 on idle and only drops to 14 under load of heater lights etc. Hopefully be able to test over next few days and see if it helps the drain or if something else behind that!!

Battery connected for 48hours now and it’s still starting fine so 🤞 that’s it sorted!

Excellent news!!