Hey, I just bought a used black 2011 Elantra Limited. It's beautiful. Bought it July 26th (just a mere 9 days ago). I love this car BUT, it's pissing me off big time! First few days were fine. Then last Sunday, went to start the car for the first time at about 5 p.m., only to find it was dead. Not even a little flicker of life anywhere. Roadside service jumped it, tested the charging system, said replace battery. Put a brand new battery in it that night and here it is Thursday, 4 days later, I go out to the car around noon, and sure enough, it won't start again! Barely any life....like the battery is dying. Once again got it jump started and was talked into buying a different battery. So, I fully anticipate in about 3-4 days, I'm going to go out to start the car, and the battery will again be dead, or close to it. There are no modifications to the vehicle. It has the OEM non-navigation head unit, etc. Nothing plugged in except a car usb charger, which I actually unplugged when I parked it for the night. No lights are being left on...all power cuts off when you take the key out anyway. So, I don't get it. What the heck could this be? Oh ya, the same day this started, Sunday, the low tire pressure light (TPMS) started flashing, then going solid, and then randomly going off, and of course, back on again. Had tires checked and they're fine. Once all sensors tested fie, a couple minutes later, only one was giving a reading. Could this all be related? It seems to coincidental for both problems to rear their ugly head on the same day. So, I'm in for some fun with this darn car. It's so beautiful but it's swiftly turning very, very ugly. Anyone else have the same issue? I see a lot of posts about people having power but the car doesn't start....this is a different issue. I have no power - the battery is dead/dying. I am open to any and all theories and ideas. I'm at a loss. Looked it up, have more questions than before. lol HELP, I WANT TO LOVE THIS CAR SO BAD!!!

 

The tire pressure monitoring system has probably very little to do with the battery dying.
But, not certain. check out youtube videos on "parasitic drain"
Will give you a better understanding of the battery problem

 

Thank you - watching it now. I think it's a bit more than I can handle though.

 

Use a clamp on ammeter hooked up to the negative cable of the battery to monitor the drain
Go to the fuse box and remove one fuse at a time and watch for change in meter reading.
When it drops, that is probably the problem area
Look at schematics (can be found in Haynes manual) trace lines to units
Dis connect units that maybe the problem to see if the drain goes away

Too much??
Then guess you will have to pay someone to fix it??