# What happened to my car? Battery went flat after I returned from a 5-day holiday. **URL:** \ **Category:** Factual Questions\ **Created:** [February 17, 2013, 5:17pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603 "2013-02-17T17:17:03Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![teddybound](https://avatars.discourse-cdn.com/v4/letter/t/8e7dd6/32.png) [@teddybound](https://boards.straightdope.com/u/teddybound)\ **Post date:** [February 18, 2013, 5:36pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/21 "2013-02-18T17:36:53Z")
I left my phone charger in the socket actually, so that might be the reason… hmm… But there was no light indicating that it was drawing any power? Well, I’ll just learn to pull the plug out next time. > [@LH75](#): > > Not long ago, I let my truck sit for twelve days without being started. When I tried to start it, the battery was completely discharged. It turned out to be the phone charger that I had left plugged into the accessory socket. ---
**Author:** ![TurboNuke](https://avatars.discourse-cdn.com/v4/letter/t/f19dbf/32.png) [@TurboNuke](https://boards.straightdope.com/u/TurboNuke)\ **Post date:** [February 18, 2013, 8:40pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/22 "2013-02-18T20:40:42Z")
> [@teddybound](#): > > This isn’t a thread about guessing my nationality, but you guys are right I am in the other side of the world, somewhere in South East Asia. > > I think I might had said it wrong that it is a ‘dry’ cell but I’m not sure. > > Here’s the website of the battery: > [Amaron - India's Top Selling Automotive Batteries](http://www.amaron.in/index.php) > > Most cars in my region uses this type of battery now.. no more managing battery fluid. Looks like a regular no maintenance lead acid battery to me, although the website has little technical info. There is a picture that looks like a lead acid battery. Also, why did you replace the battery? Did your mechanic recommend it? A fairly new battery can usually handle being completely discharged, older batteries might give up the ghost. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 18, 2013, 9:36pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/23 "2013-02-18T21:36:05Z")
Concur on all who say to replace the battery regardless. I learned the long, hard way that any battery over about two years old that goes flat by itself, or even is run dead flat by leaving a light or accessory on, is no longer reliable. You can recharge it, but it’s “broken” and certain to let you down again and again. Replace it and move on. ---
**Author:** ![Stormcrow](https://avatars.discourse-cdn.com/v4/letter/s/0ea827/32.png) [@Stormcrow](https://boards.straightdope.com/u/Stormcrow)\ **Post date:** [February 18, 2013, 9:45pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/24 "2013-02-18T21:45:31Z")
It’s got to be the cellphone charger. I live in Chicago and only really drive on weekends - I leave my car sitting from Sunday to Saturday morning practically every week, and haven’t run into any issues. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 18, 2013, 10:22pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/25 "2013-02-18T22:22:00Z")
Most cars should be able to sit for a month without noticeable battery discharge. Two weeks, certainly. A week, absolutely. I have a summer car that sometimes sits for the better part of five months without being started. I have yet to have it fail to start right up, as long as I pump the throttle and give it a little shot of starting fluid - but the battery is only a bit down even after that long. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [February 18, 2013, 10:52pm UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/26 "2013-02-18T22:52:27Z")
I’m now puzzled. Why would a cell phone charger draw any juice from the battery if the cell phone is not attached to it? Are you suggesting that the little LED that shows it’s plugged in is enough to discharge a 12 v battery in 5 days? ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 19, 2013, 3:07am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/27 "2013-02-19T03:07:49Z")
> [@CC](#): > > I’m now puzzled. Why would a cell phone charger draw any juice from the battery if the cell phone is not attached to it? Are you suggesting that the little LED that shows it’s plugged in is enough to discharge a 12 v battery in 5 days? A normally operating cell phone charger would not. However I have seen cheap cell phone chargers that draw massive amounts of current at all times. It has gotten to the point that if a customer comes in with a blown fuse for the power socket we ask if they bought their charger at a swap meet or car wash. I have seen 20A draws on these cheap knock offs. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [February 19, 2013, 3:23am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/28 "2013-02-19T03:23:40Z")
[QUOTE=Rick;16021715 It has gotten to the point that if a customer comes in with a blown fuse for the power socket we ask if they bought their charger at a swap meet or car wash. I have seen 20A draws on these cheap knock offs.[/QUOTE] Ah ha!!! Well that solves that mystery. My wife and I have had our cigarette lighter fuse blown in each car within a couple weeks of each other. Actually, three times all together. It never occurred to me that the problem might be the cheap eBay cell phone charger (which now just seems absurdly obvious. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 19, 2013, 4:19am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/29 "2013-02-19T04:19:16Z")
> [@pulykamell](#): > > Ah ha!!! Well that solves that mystery. My wife and I have had our cigarette lighter fuse blown in each car within a couple weeks of each other. Actually, three times all together. It never occurred to me that the problem might be the cheap eBay cell phone charger (which now just seems absurdly obvious. 😃 Glad I could help solve that mystery. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [February 19, 2013, 4:38am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/30 "2013-02-19T04:38:01Z")
those are hand warmers. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [February 19, 2013, 6:50am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/31 "2013-02-19T06:50:00Z")
> [@AaronX](#): > > Is it normal to change the battery just because it runs empty? depends on the battery. A lithium-ion would take a hit. A lead acid battery would not. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [February 19, 2013, 6:55am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/32 "2013-02-19T06:55:51Z")
> [@CC](#): > > I’m now puzzled. Why would a cell phone charger draw any juice from the battery if the cell phone is not attached to it? Are you suggesting that the little LED that shows it’s plugged in is enough to discharge a 12 v battery in 5 days? I had an inverter take out the power plug circuit once. It was at 3 am on a highway. The engine management computer was on the same circuit. fortunately the dash lights were on the same circuit so I knew it was a fuse when the engine died. 15 minutes with a flashlight and some rearranging of fuses and I was back on the road. It’s now marked as “evil” with a fuse marked “spare” next to it. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [February 22, 2013, 1:55am UTC](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603/33 "2013-02-22T01:55:38Z")
> [@TurboNuke](#): > > Looks like a regular no maintenance lead acid battery to me, although the website has little technical info. There is a picture that looks like a lead acid battery. > > Also, why did you replace the battery? Did your mechanic recommend it? A fairly new battery can usually handle being completely discharged, older batteries might give up the ghost. I vacation in the American Southwest (Arizona) and [these Optima batteries](http://www.optimabatteries.com/us/en/technology/) are very popular there and are usually called ‘dry cells’. Although from their website’s description they’re just sealed lead-acid. They’re popular in off-road vehicles because they (supposedly) can be mounted in any position (sideways, even upside down!) [Previous page](https://boards.straightdope.com/t/what-happened-to-my-car-battery-went-flat-after-i-returned-from-a-5-day-holiday/650603.md?page=1)