Battery Dead from Lights On for 20-30 Minutes

Yesterday my mother took my truck and brought my wife and daughter to the local park. They were there for 20-30 minutes and my mom stayed in the truck. We leave the lights on all the time and rely on the 30 second delay that is based on the driver door opening to shut them off. Since mom didn’t get out, they stayed on. Ambient temperature was low 30s.

For what it’s worth, we take a lot of short trips and my ScanGauge pretty consistently tells me that I’m at 13.8-13.9 volts while driving.

The truck needed a jump start and after driving it for a bit, the truck seems to be fine. Once my health improves a bit I’m going to take the truck to a local auto parts store - dealer is over 200 miles away - and ask them to test the battery.

So, I’m here to ask 2 questions to start out with.

Is it normal for a ~10 month old truck with less than 9000 miles to have lose enough battery charge to start in the scenario above?

If you were to replace your truck’s battery with a new one today, what would you choose and why?

Thanks for your time, folks.

 

Have read about a bunch of 3rd gens having batteries die early (insert 3rd gen joke here), contact your dealer as they have been replacing. I think you may even be able to buy one and send in the receipt and get you money back.

 

Sounds about right. 30~40 mins with headlights on is all it'll take to drain a fully charged battery to the point you can't start the engine. It will take a lot longer to actually drain the battery, but you usually can't start when it's below ~10v

 

Lights would pull close to 10 amps. If the ignition was left on, maybe loser to 15 amps. Car batteries are 40-50 amp-hour, so it was down 20-30% at least. Don't know how much power it takes to start, but at those cold temps, it doesn't surprise me that it wouldn't start.

 

I think twenty minutes with the lights on and you should expect a Group 24 non-marine battery to drop below the point that it will crank the engine.

Measuring your voltage while the charging system is operating will not indicate the condition of the battery. Let it sit for an hour and check it with the engine off. If it's healthy it should read at or greater than 12. 6 volts.

SB

 

I get whatever battery Sams is selling for a replacement and have always had good luck. A quick Google search revealed the following...

Assuming that the other lights are on with the headlights, you're probably drawing around 150 watts (55 watts per headlight, plus all the ancillary and interior bulbs). That's about 12.5 amps. Your average car battery has between 60 and 100 amp-hours of capacity. So, the time until the battery is completely drained is theoretically between 4.8 and 8 hours. Now a battery's amp-hour capacity diminishes as the amperage draw increases, so you're looking at more realistically between 4 and 7 hours.

In terms of how long until you can't start the car, assuming the car battery is fully charged probably 45 to 90 minutes.

 

Don't waste his or the dealers time. He made a mistake, he should learn from it and move on, not place blame elsewhere.

 

I never said place blame. And his mistake was allowing someone to drive his truck. And no way should the battery dropped that low in 20 minutes unless he is lighting up Fenway. And there have been a bunch of folks with battery issues on these third gens.

 

He said 20 to 30, not 20. It is entirely normal for this size battery to drain to the point of nonstart with headlights / taillights etc on for 30 mins.

 

Mine died at about 16k miles. Swapped it with a group 35 (I think) odyssey deep cycle.

 

this is why I always carry jumper cables

 

Toyota does warranty the battery and you can probably get a discount on a new Toyota battery through the dealer. I had two Toyota batteries die w/in two years on my prior 2013 Tacoma. However, I'd probably just buy an Interstate brand battery. I've had great success with Interstate batteries on prior vehicles.

 

A majority of automotive batteries in the US are manufactured by Johnson Controls. Take your pick around town (auto parts stores and big box) and they’re probably the same batteries with different branding (albeit with varying specs). I’m happy with the Interstste battery I got this last summer, mostly for the warranty. They also provide all the batteries to our local Toyota dealer.

 

Seems perfectly normal to me.

 

Another thing to add is was the radio playing, and fan blowing, dome lights on seat heaters on? All will drain a battery pretty fast

 

Were you using a microwave or hair dryer?

 

You know that brings up an important question. With an outlet in the bed, and I'm not positive but I believe it can be used at the lower setting with the truck off, wouldn't this also make one think the battery can handle a reasonable load. Something to check into more I guess.

I carry a jump battery in the truck, and I can charge with a small solar panel when we go camping or in the truck via USB, that with a manual trans, I hope to not have to worry.

 

Are you sure it was really only 20-30 minutes?

Every woman I know has an uhm....somewhat skewed sense of time.

30 minutes almost always means an hour or more.

 

Thanks to everyone for the feedback. I’ll reply to some of the specifics below, but I appreciate all of the insight. Even from the smartasses

I’ll break out the multimeter tomorrow and check it. My remote start reads 12.1V with the engine off and has since it was new, but there’s always a chance that is wrong.

I’m not too sure we could call it a mistake, but you are right that I’m trying to learn from it, move on, and not place blame.

We are a one vehicle family in the winter. In the summer, it’s the truck and my motorcycle, so letting my family drive my truck is not a mistake. That said, I made this thread because 20-30 minutes seems awfully quick to drain a battery with just the exterior lights on, and I had read about others with battery issues on the forum in the past. I’m just looking for ideas on what to check out and maybe to learn from others so that I don’t have to do everything the hard way.

Same here, my friend. They’re in the truck at all times and while they’ve been used before, this is the first time they’ve been used to start my truck.

No, it was just the exterior lights with ignition off. I know this because the 2-way remote on my remote start was going crazy telling me this. There just wasn’t anything I could do about it from a mile away laying in a hospital bed and I didn’t think to call because I didn’t think the battery would discharge so quickly.

I was using a hairdryer inside of a microwave, but neither was plugged into the truck. Smartass!

Good point about the bed outlet. We’ve never used it but there’s always a chance that there’s a ghost load if the switch got flipped even while the truck is off. I’ll check tomorrow.

I’m pretty certain, yes. I noted the time when the ladies left and my wife had to be to work at a specified time later, so it was no more than 30 minutes and probably closer to 20 considering travel time. As stated above, my 2-way remote also reminded me that time was passing so I’m pretty sure I didn’t take a nap and screw up the timeline.

 

Oh, and one more question: I’ve read on the forum here but I can’t get a clear answer: What size battery is in the V6/AT with the Tow Package? From what I’ve gathered, with tow package has a different size battery than without and the I4/V6 may even have different sizes.

Thanks again to everyone trying to help!