Car Battery Dead – Help!!!

Last weekend got back after a week away, tried to start second car and “click, click, click”, no start. It’s been in there for a few years so I swapped it out for a new one. All good.

Drove round for a few days, parked up on Thursday night. Tried to open the door with the remote, nothing. Used the key to manually unlock. Put the keys in the ignition, nothing. No dash lights, nothing. Check the battery, green light off, completely dead. Seems like something has completely drained it. What could do this or am I looking at a faulty battery?

I’d check the alternator first, it’s easy if you have a multimeter (and if you don’t have one then get a cheap one)

There could be something draining the battery. It’s often lights from a dodgy door switch but this is usually fairly obvious. Modern cars have loads of stuff that stays on making it harder to track faults

Check interior lights, then alternator, then ICE by pulling fuses and checking the voltage draw with a multimeter.

glove box light, boot light etc.

It could be a failed battery too Mate of mine had this a few years ago. Worth checking after the other easy stuff.

How old is it?

In process of diagnosing a battery issue too…. Drove to work and battery light came on and amp dial showed decreasing. Could be battery, alternator, or just the alternator regulator apparently. I’m booked in tomorrow morning to get it sorted. Hopefully not too costly as the car was in the shop last week getting a new steering rack and CV replaced. SWMBO not too chuffed…. “more car cost, I thought you said Landcruisers were solid??”

Oops. Best not mention the aircon has stopped, will be a stealth fix before summer gets here. Can’t have no aircon in 40c!!!

The battery should be 12.? with the engine off, and 14.? with the engine on. If it’s the same with the engine on and off it’ll be the alternator (and/or connections to it), easy thing to check.

I’ve got a gadget which you plug into the fuse box, take a fuse out plug it into that hole, then try the next, etc, etc, this tells you if a circuit is drawing current when you think nothing is on. A cheap and very useful tool, but I can’t remember what it’s called. Also, on my van, I don’t know about other cars, there is a special ‘hidden’ fuse box, there’s one in the engine bay, one behind the glove box and one behind the one behind the glove box, took me ages to find that, and that’s of course where the blown fuse was, everything else was good.

It’s one of those. Well, different make, but similar thing

Can’t see the link @andrewh but the widget sounds very useful.

I’m having as much luck with links as I do with pictures

Same thing, different shop

https://www.sealey.co.uk/product/5637203095/automotive-current-tester-standard-blade-fuse-20a

I’ve just found a Gunson 77068 which is the wiring part to plug into a multimeter for £10.18 – same thing. Never knew they existed – now I need one!

Thanks :)

Car is a 2009 Hyundai. Battery was fitted brand new last Sunday. Since then it’s had a few trips the last one being Thursday evening. Car was locked up and left till Saturday morning, so about 36 hours.  Just seems really weird that it has drained completely to the point that none of the dashboard lights even come on

Not if the alternator is borked.  The new battery won’t last long if it’s getting little to no re-charge.

Is the auxiliary belt still there?

Is the auxiliary belt still there?

Also a good suggestion, but tends to light up the battery lamp on the dashboard when it snaps.

glove box light, boot light etc.

Certain cars have an issue with the interior boot light, Kia Venga in particular. They were a real problem after being parked in storage for even a fairly short period, it’s down to the little micro switch that should turn the light off when the hatch is closed, but if the hatch isn’t slammed shut, the switch doesn’t get enough pressure to turn off. Sticking several layers of tape, or a small piece of an ice lolly stick to the contact point will help if that’s likely to be the cause.
It might be a glovebox light, a door switch… problems like this are a nightmare sometimes to pin down, so good luck!

@aphex_2k

Check/change the alternator brushes – it seems to be a ‘LC thing’, I watch Uncle Pooley and TJ&Mac (Oz 4×4 channels) and they’ve all had recent LC alternator brush issues.

@rusty

Cheers dude, just dropped car off. Weirdly no battery light and v @ just under 14 on way in. They’re gonna have a look and call me back. Unfortunately looking through the pile of receipts and invoices I can’t see the alternator has ever been replaced. Can’t imagine its still the original one. But will see what they find and hopefully not too spendy.

Was battery for me. 53% health. Alt is a fraction low but not a fix that needs urgency.

I’ve had a new battery be DoA before, but it was from ECPs and I didn’t check it before fitting etc. If your new battery was fitting by a garage (Halfords may not count here) they should have tested the new battery before fitting it.

Well… wasn’t “just” the battery. Light was still coming on intermittently. Turns out a loose connection on the alternator post so it was arcing and had melted the nut. All fixed albeit with $180 for an hour of workshop time. Cheaper than a new alternator though.

It’s plausible that the battery was fine when fitted, then a deep discharge from the faulty alternator damaged it.  If they’ve replaced the replacement battery without fuss I wouldn’t be complaining too loudly.

Good to hear it’s solved, for future possible battery issues, the connection to the starter motor can also be a cause of high resistance and battery trouble.