This is my 2012 Hyundai Sonata. I did not drive it for ten days. When I returned home, the battery was dead. I have never had that experience on any car ever I drove.

This Instructable applies to my car, but with all of the modern electronics running in the background on today's automobiles, your car may have this problem, too. This Instructable tells about the solution to my problem, but may be helpful with a similar problem on your car, too. 

Materials needed for this Instructable--none

  • Multi-meter with an ammeter scale capable of reading up to about three amps.
  • 8 mm socket wrench and ratchet
  • Spring clamp for connecting a small alligator clip to the battery post

Step 1: How much is the current draw?

I disconnected the negative (-) battery cable and connected my multi-meter between the cable and the battery post. (Check to be certain it is safe to do this on your car. I was reading the manual for another new vehicle and it seems some things need to be reset if the battery is ever disconnected.) The meter was set to measure DC amperes. Check the terminals on your meter to be certain you have the leads connected properly for the scale on the dial. The leads plug into the meter at different terminals for a current reading than they do for a voltage or a resistance reading.

With everything "off," the doors closed for a few minutes so all dome lights have gone "off," and the key removed; there is a current draw of 470 milliamps, or nearly half of an amp. At a recent visit to the nearest dealership for routine warranty service I asked about this. I was told that is normal. If I am concerned, I should connect a trickle charger when I will leave the car unattended for more than a week.  See the second photo. This is a battery conditioner we bought a few years ago for another purpose. I could mount it in the engine compartment and connect an extension cord to it when we will be gone for more than a week.

My question of the dealership was, "What do I do if I need to leave the car in an airport parking garage for a couple of weeks?" There are no electrical outlets in the parking stalls at any airport garage I know. 
<p>hey guys need a very big help here.<br>My Hyundai accent also faces the same problem . i leave my car in the parking for 5 days and the battery dies, but when i disconnect the battery from the terminal and later after a week also it starts normally when i connect it back . Is it battery problem or anything drawing battery from the car?? Please help , i could save some money on this </p>
I suggest you download a PDF copy of your car's manual. Then search it for &quot;fuse&quot; or &quot;memory fuse&quot; or &quot;battery.&quot; See if there is a discussion about disconnecting the electronics to avoid running the battery down after a period of non-use. Be sure to read my Instuctable carefully, especially if your car has a memory fuse.
To add to my point, i think there is problem with my head light, the head light indicator in the meter reflects ON when i switch off my car, do you think the small indicator light would be problem to drain my battery?
<p>The next time you take your car in for warranty service, ask for a check of the electrical system. The dealer did one for me at no cost. That is a starting point. Have you tested the current draw on your battery as I showed in this Instructable?</p>
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<p>well done instructable! As always hyundai has some of the overall worst engineering when it comes to vehicles. I've had some challenges with a Trajet and I wonder if those so called engineers had an ounce of common sense.</p>
<p>I use a small solar charger avail for this purpose from Harbor Freight. Sits in the dash &amp; plugs into the cigarette lighter (which depending on the vehicle, may need to be modified at the fusebox as it must remain &quot;hot&quot; with the ignition off or the charger won't work). Cost for the charger was about $15, perhaps less if you sign up for HF's email coupons (which often beat the sale prices in the flyers). Totally solved my battery going dead - also prolongs the battery's life. Had to get another charger recently though, after an extremely hot day on the dash and with the sunshades behind it - the frame melted. I bought my original charger perhaps 10yrs ago, hopefully the ones they are selling now won't melt in extremely hot weather. If the problem happens again, I might just leave the panel propped on the passenger seat where it should remain a bit cooler</p>
<p>Solar cells work great and are very well made. Put one on in your windshield facing th sun for a few hours connected to your battery been working for a long long time. Never a problem.</p>
My car is not exposed to the sun when I leave it.
<p>Solar cells work great and are very well made. Put one on in your windshield facing th sun for a few hours connected to your battery been working for a long long time. Never a problem.</p>
<p>if you have a battery that is dead after such a short time, there is either a MAJOR drain from the car or the battery has been &quot;deep cycled&quot;. If the battery in most any car has been drained to the point of barley turning on a bulb in the car or left dead for a longer time, then it most likely would never hold a charge again. Also, charging in the car by driving for a bit is hardly going to get the charge back to where it should be.</p><p>I would suggest you demand Walmart replace it and demand they perform and show you the results of a Load Test on the battery.</p><p>Another thing to remember is many people and even some mechanics or parts places will replace battery that they believe is the same size, MANY times it may be the same physical size but it also needs to be the same amp hour rating and cranking amp rating or there is no point in buying it. Never skimp on battery size.</p>
<p>I am trying to look thru this thread for an answer but it doesn't help - I have a 2012 chevy suburban. If I dont drive for 1 day, the battery is dead. I recharge and drove to walmart. they say battery and charging system is good. wont replace battery (which is about 8 months old). If I sit in my car with ignition on the setting &quot;on&quot;, (car not running, within one minute, digital thing says &quot;battery low&quot; or something.</p><p>walmart refuses to change battery and says there is a drain but NOTHING is on!! please help me. </p>
Holli, Your problem is more serious and aggravating than mine was. I am not a trained mechanic, but come from the school that tries the cheapest fix first and goes to the more expensive fixes when those do not work. I did a little digging on the Internet. It seems owners in slightly earlier years going back to 2009, even 2006 experienced similar problems. At this <a href="http://www.gminsidenews.com/forums/f31/battery-goes-dead-86315/" rel="nofollow">link</a> I read inquiries from owners. Some found the solution in having an on-board computer reprogrammed with updates, often a BCM (body control module). Sometimes these computers apparently draw current for things that are not even &quot;on,&quot; like the sound system. (I do not know how that works.) Failing all else, you could add a quick disconnect switch to isolate the battery when the vehicle is not in use, but then you will be continually adding your radio presets and resetting your clock. I wish I could give you an exact fix that is easy, inexpensive, quick, and effective.&nbsp;
<p>Thank you Phil for this post. I just found your solution to my problem. My battery dying problem started happening to me about a year ago. Hyundai put a brand new battery in my car and the problem continued. My solution was to pull the positive cable off the battery if I went on a trip or if I wasn't driving my car for more than one day. I always carried jumper cables with me too! I don't know why I didn't google and find an answer sooner. I hope this works, I just pulled the yellow plastic holder out just past the &quot;click&quot;. I will take my car in on Monday and see what the dealer says about this. I don't believe I should have to jump my car all the time or pull fuses with any car to make it run, so unless they fix it, I don't want to drive it. This problem is irritating to say the least.</p>
Thank you for your comment. I am glad it was helpful. A friend has a newer model than my car, and it does not have the same yellow disconnect. I am not sure what that model does to prevent the discharged battery problem. <br><br>It is a shock to have a car that loses its battery charge in a few days, especially after years of driving other cars without this problem. It is frustrating that the company and the dealers do not know about the disconnect and talk down to the customer as if the customer should be content to call and wait for roadside service.
<p>The battery has gone dead on my 2010 Sante Fe on 3 different occasions when I have just sat in it with the engine off and no key in the ignition but I did have the windows down and was using the Bluetooth on my cell phone. Even though the car wouldn't start, I could still close the power windows. It has been fine after being jumped~guess I'll just get a new battery since it is the original battery. I was just curious how there could be a draw of power with no key in the ignition. Thanks, guys.</p>
Current draw while the vehicle is parked and not at all in use is the problem. If you look back through the steps of my Instructable, you will see that my 2012 model has a draw of nearly 1/2 amp. while it is just sitting with no key in the ignition. All sorts of computer circuitry runs in the background. When I found and pulled the special fuse, the computer stuff was largely shut out and current draw dropped to 1/10 of what it would normally be, which is about the amount cars once drew before the advent of cars run by computers. I would encourage you to download an electronic copy of your car's manual in PDF. Then search it for &quot;fuse.&quot; If your car has the same special fuse my car has, you will find the information.
<p>Dear Phil B,<br>Thanks for your info. <br>Personally I think that your car is Azera/Grandeur codename:HG not a Sonata!<br>Please be informed that even if you park your car for 2-3 days(not such a long time like in the airport as you said), this symptom will happens.<br>Yes you are right. that current is so much.<br>But based on my experience, your Instrument Cluster is leaky. Reason is that if you pull out Memory1 fuse(which feed up cluster as well) where is in the passenger compartment fuse box, mentiend dark current would drop to half.<br>So, I recommend you to replace your cluster with a healthy one.<br>And after that tell the dealer to do variant coding for it.(if not, the language will be in Korean not English).<br>Regards,</p>
<p>Thank you for your comment. I can assure you my car is a Sonata. I have left my car unused for a few days and the battery still started the car. I read on a Hyundai owner's forum that owners of some models had problems with a depleted battery that was traced to a design flaw in the car's radio. I did not find anyone complaining of an abnormal electrical drain in the instrument cluster. From what I have read, newer cars have a lot of functions governed by the car's computer that run continuously in the background, even when the car is not running, so that a heavier current drain is normal. The dealership did check my battery and charging system. Those are normal. </p>
2000 Corvette (30mpg BTW) started doing this 2 years ago, never have been able to track down the cause, so I bought a knife switch disconnect to put on the battery, which works great. <br> <br>Google for <br>car battery knife switch disconnect
A knife switch would be a good alternative if some feature like I described is not built into the car. There would be an investment of time and money.
A new thought on this lost memory fiasco matter.<br> <br> There may be a collusion between&nbsp; Hyundai and the battery mfg to perhaps sell more of something.
My theory is that Hyundai wants to sell its roadside assistance service, which carries a subscription fee after an initial &quot;free&quot; period. My wife signed us up for AAA a couple of years ago. (My preference was always to do preventative maintenance and to carry a few tools. That approach has worked for me over more than four decades, even with some older high-mileage cars.) When the Hyundai salesman asked if I wanted Hyundai's roadside assistance service, I said we already have AAA, a GPS, and we have cell phones. He agreed we were well-covered without Hyundai's service. But, consider the response I got from Hyundai of America. Instead of warning owners about the memory fuse as a preventive measure, they want to talk about enrolling in their roadside assistance service.
Very informative, just another greedy company. <br> <br>The switch idea sounds good too.
sad. this is just really really sad. <br>On my old beater car, I start it up, and run it for a while every MONTH. <br>and not because the battery will go flat, but to keep the moving parts loose and lubed. <br>As for battery drain, once I found the grounded short, and fixed it... the only way the battery is even partially drained(much less dead) after a week is if I left the parking lights on(dead battery in ~22 hours). So... your brand new car drains the battery 7 times slower than my 15 year old car with the lights left on. I think we found a problem <br> <br>and flat in a week? REALLY? The SO's 2010 Ford escape has around a 45mA draw when parked and off. I think there's something fishy at that particular dealer. Or maybe it's just that particular car model? <br> <br> <br>I think, as a stop-gap measure, I would seriously have to consider replacing that fuse with a toggle switch. Seems SO much easier. <br>So weird that for 1 week worth of storage they make you disconnect the audio and lighting, just so you'll be able to start the car when you get back. Is there room under the hood to run a dual-battery set-up?
The rate at which current is drawn from the battery is a surprise that was not mentioned when I was purchasing the car after doing a lot of comparisons with several other models, some of which also had some surprises. For example, I strongly considered a VW Passat TDI, but there were two nasty surprises I discovered on it. The engine requires seven gallons of auto grade urea every 10,000 miles to keep nitrous oxides in the exhaust low, and auto grade urea costs around $7 a gallon or more. The other surprise was the high-tech DSG transmission used in those cars is supposed to have $800 in service every 40,000 miles. If a home mechanic wants to attempt this service, a $125 kit is necessary. The advertising brochures do not mention those things. <br> <br>As much of an unpleasant surprise the potential dead battery is, I am glad to know there is a relatively quick disconnect in the form of this memory fuse. At least there is a way for me to leave the car unattended for several weeks without needing to call for someone with jumper cables or a tow. My main pain now is wondering why the dealer did not seem to know about this. <br> <br>The space under the hood is full. I first looked for a place to mount the battery conditioner pictured in step 1 and struggled with that. There is definitely not enough space for a second battery. As for a toggle switch, I would need to get behind a fuse panel mounted low in the dashboard and then find the right wires. <br> <br>As I mentioned, owners of several makes and models are having problems with batteries that go down in a few days. Not all appear to be design problems, but faulty components. But, a big question for me concerns my friend who has had two of these cars. He says he has left them for more than a week and the battery was fine when he returned. My dealer ran a detailed diagnostic process on the battery and charging system and found everything as it should be. That does not answer the question of a faulty component downstream that is sucking juice. A few years ago the Hyundai Azera had a faulty radio that easily shorted to ground and caused dead batteries. <br> <br>Right now I am assuming I may simply be dealing with a new reality.
One thing that comes to mind as I read this discussion is the delar's experience with cars on his lot. Do they go out and start every car once a week? Maybe- to shuffle them around for display purposes..... <br> <br>At the dealership where I work (non-Hyundai), I know for sure there are cars that sit for more than a week without being started. <br> <br>Not to be panning Hyundai here, I just am a little suprised that the dealerships seem never to have run across this problem in the operation of their car lots. <br> <br>
I had the opportunity to go to The SEMA Show in Las Vegas in early November. There I stopped at the Hyundai booth and talked with a test engineer. He was very sympathetic and did not blow me off as I had expected he might. He did say the dealer have cars on their lots for a time, as well as dealing with cars arriving from a distribution point. The memory fuse is for dealers to use in order to keep fresh batteries in cars on the lot. He also said turnover is a big problem at dealerships and it is difficult to keep the right information in the heads of everyone who should know certain things. I did also talk to a friend who once trained to be a Hyundai salesman, but now works in a Toyota service department. He thought Hyundai's policy on all of this is quite humorous. I do not know what Toyota does, but they apparently do not have these problems. He did say his sales training at Hyundai mentioned nothing about the memory fuse. Thanks for looking and for your comments.
So, I gather the intelligent dome light + control is always sucking 470ma...<br> <br> What an outlandish design fiasco ##!!@@??..................<br> <br> Most EEs can design a&nbsp; self turn-off that draws No further power and<br> a restart magnetic reed switch that needs no power to activate a uP...<br> <br> A
The yellow plastic fuse holder encases a 10 A and a 15 A fuse. The 10 A fuse is marked &quot;Room&quot; on the fuse identification chart and seems to control the dome lights and dashboard lights plus whatever else. The 15 A fuse is identified as the &quot;Audio&quot; fuse. I removed the 10 A fuse from the yellow holder and inserted it alone into its socket. The current draw was 330 milliamps. So, I figure the audio circuitry draws 140 milliamps when in a state of rest. When I open and close the door so that the dome lights are on, as well as the dashboard lighting, the current draw shoots up to 2.99 amps. until the dome lights, etc. shut off in a couple of minutes. 470 milliamps is the constant draw with both fuses in place. The dealer claims the computer circuitry draws the nearly half of an amp. in current.
OMG ( Oh My Goodness ) That suggests that at the airport parking lot<br> your car alarm will be non-operative !<br> <br> A
I am not sure about the alarm. It could be inactive. I am more concerned about not being able to start the car. I tend to buy and drive cars that are seldom stolen, and I do not leave valuables in plain view.
As a brainstorming idea- you could leave a charged jump pack in the trunk for when you return....
That certainly is an option. I think a jump pack is about $100. I expect it would become one of those things like a spare tire. Everyone knows they need to be kept aired, or, in the case of the jump pack, charged; but, no one gives it much thought until it is needed in full working order. Since posting this I have left the car twice for ten days or slightly more each time. I pulled the memory fuse each time and the car started just fine when I returned. <br> <br>Also, I talked with a neighbor who drives a Mercedes station wagon. He has the same battery drain on his car.
That's 6 watts draw with the car off which is astonishing. If you wanted to keep the battery topped up with a solar charger, you'd need 6 watts * 24 hours = 144 watt-hours of energy each day, and if you get an average of 4 hours of noon-power sun (the low-side of average for northern climates). That means you'd need a 36-watt solar panel which would cost close to $150. Yeesh. <br> <br>I once had a problem with my old Buick Roadmaster wagon where the battery would get low fast. One of the interior lights was left on: there was the door switch and the dome-switch which would turn all of them on, but also 2 map lights, 2 rear-passenger lights, and 2 cargo lights each with individual switches at the light. It was the dim one behind the driver seat which I never happened to see. Too bad it's not as simple as one of those!
In the last few days I have been doing a few Internet searches with a string like &quot;car battery goes dead in a few days.&quot; From the hits I am seeing, it appears automotive electronics industry wide are moving toward on-board computer systems that draw more current than we were raised to think a car should. Certainly, some of those who post are looking for help identifying and fixing a defect, like a bad battery cell or an unexpected short or a faulty diode in the charging system. But, many are simply running into the reality that some cars draw up to 600 milliamps when everything is thought to be &quot;off.&quot; For example, Ford now has a &quot;keep alive&quot; fuse comparable to Hyundai's &quot;memory fuse.&quot; <br> <br>By the way, I did pull down the back seats so I could see if the trunk light was &quot;on&quot; and I opened the glove compartment a crack to make sure its light was not &quot;on.&quot; Neither was malfunctioning. <br> <br>About four years ago I read &quot;Physics for Future Presidents&quot; by Richard Muller and recommend it highly. Solar cells are expensive and not very efficient. A rider in good condition puts out energy comparable to a solar cell array powering an experimental electric vehicle. You might do as well by driving a small alternator from a stationary bicycle. <br> <br>Thank you for looking and for commenting.
To go on a tangent about solar ... <br> <br>I installed a system on my roof&nbsp;&mdash;&nbsp;4KW &mdash; which had a real cost of US$23,000 but I got a New York State credit and had to pay $16,000 out of pocket, and I will be getting $9,000 in tax credits, so my cost was more like $7,000. It's estimated to produce about 4,000 KWH per year for 25 years. <br> <br>One thing to consider is the actual cost of electricity. I'm paying about $0.08/KWH, so the solar system produces $320 in electricity each year ($8,000 in 25 years). But I also pay $25/month just to be &quot;on the grid&quot; &mdash;&nbsp;the connection fees and such. In 25 years, that works out to $7,500. So if I were to go off-grid with this system (not a totally fair comparison), I'm up to saving $15,500. In remote locations, it often makes sense to go solar before you even hook to the grid: purchasing and installing the cable to connect to the grid is often many thousands of dollars. <br> <br>The other thing that changes the game is independent electricity production. If everyone could produce their own electricity, there wouldn't be a need for centralized power plants and the massive distribution network that entails &mdash;&nbsp;mostly all that copper, telephone poles, and long-distance transmission lines. It's easy to nitpick the details (would a maintenance vehicle really be removed from service if individuals would require it anyway) but I think you can see how it would be radically different. <br> <br>I don't know if it works out dollar-for-dollar or pollution-for-pollution or material-for-material, but it's certainly something that is a plausible alternative.
Government subsidies mean other taxpayers who do not benefit from someone's solar installation must pick up the expense. Alternative power sources need to work on their own as a thoroughly practical solution without subsidy by other taxpayers who derive no benefit themselves and without ideological commitments to an environmental philosophy to prop them up.
Solyndra any one!
This would be a good time for me to explain a little about Richard Muller's book &quot;Physics for Future Presidents&quot; and why I recommended it in a response to a comment. Muller is a very popular physics lecturer at UC Berkely. The book was written before the 2008 elections in the USA as an open letter of sorts to whomever would become the President, because he would be called upon to make weighty decisions on numerous matters from energy to environment to defense, all of which would be aided by a sound basic scientific knowledge. The problem is that all of us think we know things we really do not know. Because we have wrong information we make wrong choices. Muller's book explains how things really work, what is true and not true, in several important fields. The book is apolitical completely.
Alas, all things [in the U.S.] work on government subsidies. <br> <br>E.g. do you think the grid is self-sustaining?
&quot;Solar cells are expensive and not very efficient&quot;. <br> <br>Boy, isn't that the truth! Have to be better ways of capturing solar energy. <br> <br>Solar PV cells are 10% - 15% efficient. But if you just want to heat water directly from solar energy, effiency is easily 50%. <br> <br>
Thanks, Bill. I marvel at all of the things transistors do, and yet, they are basically made from sand. It makes me wonder what else is under our feet that could do similar wonders, if only we knew what to do with it.
I made this update to the text of the Instructable on a car battery going dead or flat in a little over a week. I am posting it as a comment, too, so those who have already seen the Instructable and commented on it will be aware of the update information. <br> <br>UPDATE: October 9, 2012-- A friend who owns a 2013 Sonata spoke with his dealer in a different state and city. He did not let the dealer know he is aware of the memory fuse. He asked about the battery going down in a short time. The dealer said new cars of all makes and models have so many electronics items running in the background, even when everything is &quot;off,&quot; that the battery on newer cars will go down fairly quickly. When my friend asked what to do, the dealer advised buying a trickle charger. Then my friend asked what he should do if he needs to leave his car at an airport lot for a few weeks. He got only a blank stare from the dealer and no answer. Then my friend led the dealer a bit and asked if there would be any kind of fuse that could be pulled to reduce the current draw. The dealer said he did not know of any!
Nice job! <br>This made me think, that the maker of the car should have maybe hidden a (vacation) switch....
Thanks Phil. Good info.
Thank you. Thanks for looking.
My wife's 2008 Santa Fe has the same issue. Her previous car was a 2001 Santa Fe. It could be left off weeks at a time with no battery drain issues. Some time in between appears to be when Hyundai made some electrical changes. <br>Good info about the fuses.
Ray, <br> <br>I feel guilty doing an Instructable on information that is in the owner's manual, but I would wager most owners are not aware of that memory fuse disconnect. It seems good to do an Instructable that will later show up in an Internet search by frustrated owners who are trying to figure out what in the world is happening with their vehicle. I have to say I very much like the car and have no intention of trading it. (I recently brought two pieces of concrete reinforcement bar home from Lowe's inside the car and each was ten feet long.) I assume you will check your wife's car to see if it has one of these disconnect fuses. I would be curious to know what you find. If you get the chance, ask some questions of your dealer and let us know what you were told about this fuse disconnect.

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