Modern batteries, fitted to cars with stop/start systems and loads of other electronics, can be quite temperamental. I'd suggest doing a full trickle charge, as suggested.

A friend of mine has a van, he'd been away for 4 weeks. Battery was dead. He tried charging it up with a (probably) 20 year old charger, and got nowhere. My modern 'pulsing' charger, on the other hand, got it back to top condition when it was left charging over a weekend.

Mine is a CTEK smart charger (can't remember the exact model, but I seem to recall it cost in the region of £50). It's regularly used for a classic car (Morris 1000) and a modern quad bike. Auto-switching, it's literally a case of attach terminals, switch on, and leave it to do the job.

Get your multimeter out and test your battery yourself

https://youtu.be/AT_XmlwMVz4?list=PLOaePmzqZNJ24dTPG6x570Pze_D4Cxy6F

Those capacitive testers dealers use are unreliable, a proper load test is the way to go. They probably don't get paid to do a proper load test even if they replace the battery and Hyundai (like others) are probably clamping down on battery changes in warranty due to too many doing it willy nilly.

"The car charging system apparently will only charge it up 'so far'"

This is quite true - watch my video and you'll see I address this point at around 6:18

Get the battery hooked up to a charger before you test it.

" Perhaps the climate control draw was high?"

Not a chance. The compressor is engine driven, so even with ignition on and engine off there would be little draw - most cars will only run the interior fan with engine running these days.

"Hyundai are not recommeding that it needs changing"

You'd think they'd jump at the chance to sell you a battery! So, what else is going on?

22k a year - I guess that's not all city driving? As mentioned above check voltage drop across cables. Check all cables for security and connection quality (including earths). Check the charging system.

Thanks all.

Although my driving pattern has changed in the last 6 months, with more short(er) journeys (20 mile round trips more frequent now) - I still do a good deal of longer journeys.

The battery was trickle charged by me after the 2nd event, so I thought that should be the end of it. The fact it re-accured so quickly worried me.

I'd expect Hyundai to recommend a battery change, just for the revenue, especially as it is out of warranty.The fact they haven't is comforting, but on the other hand leaves me worrying aboiut being stranded somewhere without a friendly motorist whose car I can use to jump start!

The 3rd and 4th times were relatively short periods with only the radio one (and volume low) and still the car didn't have enough juice to turn over. This seems to indocate something deeper and that the dealer (who has serviced it throughout it's life, one owner from new) should be trynig a little harder to understand the underlying issue.