Reader Question: Intermittently Dead Battery?

Here’s the latest reader question, along with my reply! 

Mike asks: Hi Eric, I listen to you Wednesdays on Bill Meyer’s show and I read the review you did on the Kia Sedona circa 2015 model. I liked that article. When it comes to cars I am a real non mechanic type and know very little. I own a 2016 Sedona and really like it. (I’m driving a hot rod!) Not quite 19k miles on it mainly around town (Grants Pass) – I am retired; sometimes I won’t drive it for a week or so. I was wondering if you may have heard anything about a dead battery problem in this car?

It’s been dead a few times since replacing the battery last July. A local mechanic troubleshooted the system but no cause found. I trust him, he is very good. There aren’t any aftermarket, modifications or add ons to this car. All scheduled maintenance done on or before due. The alternator is ok, battery too. Kia wants $140 bucks an hour to figure it out. I can only guess that possibly was it because of recall work related to sliding door or passenger seat wiring harness both performed by KIA service? Something changed afterwards? Also, what if I tried to turn it off when I was driving it by unintentionally pushing the on/off button? Or turning off in gear? Fried something? Duh. Any ideas would be appreciated. I bought a battery tender and that is really doing the trick but I am wondering what the root cause may be. I used to leave the Auto setting for lights on but no more, I always shut everything off (radio, heater, etc.) before turning off. Nothing using auxiliary. When it does a system check at starting up it is ok. UVO system check is ok too. PS: Why don’t they have a battery level indicator any more in vehicles? It would be helpful in my case. Thanks!

My reply: A slight draw (with the engine off and thus the alternator not charging) will drain the battery over time; this can be frustrating to trace. The first and obvious thing is to be absolutely sure – double check! – that the ignition is off (accessories off, too) and that the interior dome lights are not manually on – I have drained the battery in my truck this way! Check that nothing is plugged into a 12V power point, too – as in some vehicles, these remain “hot” even when the ignition is off.

Be sure that all doors are fully closed.

If these all check out – and the battery still drains – the easiest and cheapest thing to do is keep it plugged in to a tender will maintain the battery’s charge.

Another thing I’d do is install a cut-off switch on the battery for those times when you have to park the vehicle for an extended period away from access to the tender. This will, of course, cut power to the audio system and thus all your presets will be lost – but it’s a failsafe that will prevent you from returning to your vehicle after a few days and it not starting up.

Hoping it’s just the dome light!

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