Will my car battery charge if I leave the engine running?

Can you charge your car battery leaving the engine running on your driveway? In this video using my 2019 C43 AMG we test if this is possible.
With the current in place many of us are not regularly running our cars so it's important to take care of our batteries and make sure they don't run flat.
Here's my experience charing the battery on my 2019 Mercedes C43 AMG saloon without driving the car with the engine running on idle.

[@TecraX2]

TLDR: Answer is YES!

[@josh-lewis]

I’m so thankful for people like you.

[@plainjaneofalltrades3853]

Thank you! Sheesh!!!

[@OryanMcLean]

Thank you

[@dizzle6709]

Holy frick I’m like skip skip skip wtf!!!

[@papabear5411]

this comment is sigma , no need bla bla bla, Thank you very much

[@darwinismresearch-trolling7271]

Starts after 1:45 get to the point 2:30 and spills the beans at 3:00 recommends 30 minute drive or idle in driveway cautions you can''t lock the car while idling so beware thieves. Once the car is started you don't need the key so that is a good tip if you own a merce. I like the comment by MR DPC. Stay wellmate thanks for the video.Liked

[@AiDHDtv]

TIP: SKIP TO 3:33. YES BUT FASTER IF YOU DRIVE AND MORE SAFE THEN LEAVING UNLOCKED CAR ON DRIVEWAY. No need to watch 325 seconds of footage for 10 seconds of info but thanks for making the video. 🙏🏼

[@pfeamg9658]

Really glad you are well again and fully recovered. Thanks for another great video Adam.

[@Straker1923]

Thanks for the video. My Golf GTi played up recently too. Wasn't sure how long to run the car for, this helped enormously! Glad you are ok now too!

[@albertl2700]

Happy you are recovered now and safe and well, keep up the great work!

[@srgiosim]

Great to see you healthy! Congrats on the video and good work! 💪🏽

[@joeymarcello9267]

2:56 you’re welcome

[@IDABAYAREA650I]

*Thank you! fucking 15 seconds of a video stretched out to a bullshit **5:25** second long video*

[@MelloDeeBeats]

Much appreciated

[@bartzeegers3663]

Good your safe again, the car looks great in that color. I own a c220 avantgarde.

[@mr-dpc-5018]

Your battery will take charge on idle, as long as the alternator is giving out 14 volts plus it will charge the battery. You could check it by putting an amp clamp on the negative lead to see what the battery is accepting if you want. Usually about 45 mins will do if the battery is serviceable. Lock it up manually with the key.

[@tocrob]

The charging amperage is relatively low after ~15 minutes ( 1-3 amps vs 10-30 amps) .Best practice is to use an external charger to top it up ( ac/dc or solar ).

[@Pinkielover]

except lots of cars only put out 13 volts max

[@mr-dpc-5018]

Modern cars with AGM and EFB batteries take lower amps but alternators pump out 14 to 15 volts.

[@sunday6092]

Hey AMG owners. Don’t know if it’s the same for everyone, but my 2019 E53 will not let me start an unlock car utilizing the Mercedes me app. The vehicle has to be secured to start & when opened it will stop the engine. Be safe & enjoy the AMG experience.

[@diademglow3429]

Yes! My 2007 CLK is starting but the battery light is on. Mine sat for very long. Thank you for that caveat about leaving it running. Be well.

[@ESMorg]

Man thanks!! I just got a Mercedes and was freaking out about the battery charge. Very helpful!

[@ABAUTOAMG]

You are welcome! Enjoy your new car :)

[@osloldschoollegend2191]

Thanks for the info which was much needed. Stay safe!

[@ABAUTOAMG]

You are welcome, thanks for tuning in! :)

[@dimeolas777]

Good to see you well. Good video. My brother in Cali hasn't driven his car since the start of covid and is worried about the gas in it. I'll have to tell him he needs to check his battery as well. I dont think he's thought of it. Stay safe.

[@ABAUTOAMG]

Thanks mate, hopefully his battery is ok and it starts up. Will be good to give it a little drive if it's been sitting for a long time too.

[@stevepinder8596]

Wow I received the same message last night re my 2018 C43 Coupe and I did exactly what you suggested, think I will run the car every other day whilst it’s not being driven.

[@stephencooper7514]

Always informative and helpful.

[@ABAUTOAMG]

Thanks Stephen!

[@globetrotter8556]

Thanks for sharing this info as my place is currently in lockdown mode and I haven’t used my car for some time.

[@ABAUTOAMG]

You are welcome. Stay safe! :)

[@alexkr3968]

very helpful video!

[@edwardedward7974]

Thanks for the very useful information Cheers Eddie

[@Drazorig2]

Had this same issue during the first lockdown and now....... The W205 models are known for this battery issue, the most annoying thing is the shift to P message stays on the central screen and you lose access to your menu settings until you resolve the problem.

[@rouf_ff2071]

Thanks for providing such a helpful information

[@ABAUTOAMG]

Glad it was helpful!

[@almina1084]

Very helpful thank you for this video

[@albertocardenas5685]

Awesome and useful video! Gretings from Mexico! Alberto

[@ABAUTOAMG]

Thank you! 👍

[@chrisryan8894]

Great tip. Thank you. I have a 2017 c43 and the Mercedes me app won’t work for it. But I have the light in my dash on that says stop vehicle and leave engine running with a pic of the battery. I never thought of putting into sport + mode. Going to try that now. Thank you

[@WriterandPhotographer]

Usually, if a person is just driving around, the old rule of thumb was that you needed to drive 7 miles for the alternator to charge the battery the equivalent of one start. I know that my C-class sits in my garage so much that right now, the battery is so dead, that I can't even use the key fob to open the doors. (or put up the hood (bonnet)) in order to put a charger on the battery. Manual key will cause the alarm to go off and then I can't start the car to turn it off. Good video........with the cost of gas (petrol) these days, it may be more worthwhile to take a drive. Btw.....color of your car is beautiful. Would trade that for my graphite grey metallic.

[@ahemgee9542]

Trickle charger is a better idea, better for a battery and avoid having the engine idling cold which circulates oil that is less effective.

[@worldofrandometry6912]

I've been getting the battery critical message on mine for about 18 months now. I was told by a garage that this is a known fault caused by resistance in some module attached to the battery terminal. Even though the car has never failed to start I think I might change the battery anyway as it's coming up to 5 years old.

[@hrivers728]

THANK YOU foR THIS INFO !😄

[@iEditProjects]

Going through this now. Started my car with a jumper box after a month with it sitting. The car died ⚠️ around the corner while driving it so it’s just idling in the driveway now.

[@reiannaidoo]

*****MUST READ***** Great video. I do the same. But it's best to leave the ac running on the lowest temperature with the recirculate off "pulling air from outside" This keeps the radiator fans running all the time, keeping the engine compartment cooler and stops the engine heat cycling and helps cool the alternator which is working very hard at this time.This will not affect the charge rate by much and your car will thank you for doing this. I don't want to get into all the benefits of this it will take to long.

[@philipjz]

Is this true? if you wanted to protect any components it would be the engine. Very expensive to replace vs. alternator. Best to go out for a drive so the engine reaches optimal temperature quickly which I believe reduces wear.

[@reiannaidoo]

@@philipjz 90% of engine wear happens on startup. So i rather leave the engine running than stop start all the time. The engine runs up to 15 deg c cooler with the AC on than with it of. So it saves al the seals from cooking and hardening. I have a civic with 300000 plus miles engine runs like a dream i have been soing this for the life of the car. It's 12 years old now.

[@SaD_kNiFeYT]

Top comment and helpful ❤

[@dawnsreviews7205]

If your battery is already a little older ..take it out once a week or use a trickle charger. Mine did not start up after two weeks of being idle.

[@billclarke7893]

good to hear you are feeling better Adam, I was wondering why there had been nothing posted recently. Stay safe

[@ABAUTOAMG]

Thanks mate, good to be back :)

[@johnmachinmegavegan8378]

I retired recently, and stopped using my E-Pace so much. We've three supermarkets within walking distance, so I hardly needed to use it at all. Then, of course, when you finally want to use the car, you soon get the 'Low Battery - Start Engine' warning. To obviate this, I had a brainwave - buy a BEV! ... Then I found out this wouldn't solve the problem, because BEVs use the same kind of12-volt battery to start the engine, and this is NOT charged when the engine's batteries are charged. (I asked a Jag sales bod about this - he didn't know!) Anyway, that saved me spending a bloody fortune pointlessly. I'm now trying to keep the battery charged by driving to an out of town supermarket twice a week (2 x 13 miles round trips). I keep the radio off, and close the rear hatch manually. Working okay so far.

[@ep91monster]

The app is only reporting the battery voltage to you as the car is running and actively charging via the alternator. Once you shut the engine off the battery will slowly drop voltage to its actual charged voltage state. So you cant really use that as a method to tell charge state lol

[@naeliv6099]

I Love My 2013 Honda Accord EX-L Coupe I have it for 6 months and a half, and i'm so soft, and careful on driving it, and I love it's driving, also I respect the speed limits while I drive it, also When I Start it up i leave it couple of minutes until it charge it until the courser moves up and I Move It, but i'm in it, So My 2013 Honda Accord EX-L Coupe Car I used, and still use to switch it on, and i'm in it, and I leave it charging with hand brake up, and on park, so does it affect the car?

[@Xanthopteryx]

Modern cars charge just fine. No need to turn off things. The load the generator can easily handle, and if the car needs more power it will increase the RPM automatically. Older cars, there you might need to rev the engine first to trigger the generator so it starts charging. It depends on what type of generator you have. A normal generator can put out up to 150+A in todays cars (depending on the car of course). Around 100A is not that uncommon. At Idle it will give tenths of amps, could be 40-60A. The biggest stopper here is the battery that can only handle around 10-20% of nominal capacity, so if you have 80Ah it can take up to 8A-16A (roughly) - AGM batteries are rated to around 30-40A normally, but to preserve battery you really want lower than that.. That is maximum and already at around 80% charge, that will go down more and more the more charged the battery is. So it can go pretty fast to get to 80% charge but the last 20% can take hours without problem. When you are at 90% you might be charging an 80A battery with just a few A.

[@gehacktetYKzZY]

Thanks mate, very informative. I am about to have a 37-day Business trip without my car and unfortunately I do not know anybody who could from time to time start my car. So, I smell some issues on my return. And I am totally ignorant regard to this type of situation.

[@mereobserver1727]

Greetings from Kazakhstan! Out on a one month rotation too, with no one to drive it. Hope your car will be okay. Worst case, battery runs low and tyres develop temporary flat spots - both of which tend to fix themselves after a little driving. The higher the pressure, the better tyre preserves its shape - so long as you don't go overboard (eg 45-50 psi and above). In my case, tyres are pumped to 40 psi each (225/45 R17). Got relatives to auto start the engine once a week for 15 mins, but even without this procedure, there are reports of cars left in cold storage for 3, 4, even 6 months - with no major issues. Fuel additives are definitely needed for long term / seasonal storage, with one month being a soft threshold - exceeding which by a week or two should be just fine.

[@babagandu]

You can disconnect the battery or remove one cable, I forgot the method

[@alexkierontylernathanmitch5111]

Cheers!

[@transit921]

exact question I had

[@TheCoomer]

Car chargers are £15, may take an evening though to charge

[@Rhaman68]

A portable battery charger or trickle battery charger will do the job w/o running the engine and causing exhaust pollution. Thanks

[@Sambam1981]

Your car is clean

[@bakervinci163]

Great video. Would have been better had it been one minute

[@jdb6284]

Cap'n here: Car battery should charge to max if leaving it running for 30 minutes; according to my roadside assistance contact. You can lock you car potentially with your spare car key.

[@Dtigernumber1]

i need advice please. i have Kia Ceed petrol 2008. not been driven for a month as I'm sick and not able to drive. can someone advice how long it takes to charge a battery while idling? or have to drive? or it can be started without any problems?

[@mzhou05]

2010A4, now after about 20min idling it's 30%, so definitely don't need to drive around. 1hr idle should give me 60-70% and should be good for another 2-3months no driving.

[@drellaveli3313]

Benz need to make us lock doors while quick store run or leave in driveay

[@GeneralKato]

Yes. Let it idle for 30 mins. Stay in the car to be safe.

[@conned]

Reason you can't lock while engine is running is a safety feature,due CO poisoning. But yes, security is a risk. Can't win them all

[@coindigger5392]

When you want to toot your own horn having a Mercedes and a battery topic is the answer..

[@AllanDMartins]

Yes it works with most of the cars, one tip when it comes to FORD models, particularly the modern ones, if you leave it idleing itself will do the job, perhaps, the alternator on these models are equipped with a inteligence wich only charges 14,5 Volts if you turn on radio, low beam, fog lights and that radio. It may sound crazy, but if you have a multimeter at home, and a 2018 Ford focus (example) you should see that the alternator charges 12,5 volts when idleing with every thing turned off, and it actually starts to charge the battery up to 14,5 volts when the system understands it´s required to do so.

[@tocrob]

Most vehicles on the road are like that. The initial charge voltage may go up to 14.8-15v especially in freezing temperatures ( PCM controlled charging can also use intake temperature as a variable ). And the charging amperage may stay high ( 20-30 amps) for a few minutes while idling ( depending on the battery's charge status ). The main reason you might want to drive is because just idling is not healthy for the engine/combustion system.

[@yankeydoodoodoo]

Long as the Alternator is working..You don't need to drive it.. The Alt is what charges it!

[@vincehenriquez680]

So if the car battery is completely dead how long should I let it run for in the driveway? I let my 2005 Volvo XC90 charge for 40 minutes and then I turned it off and waited ten minutes and it wouldn't turn back on. It died again. Does that mean my battery is just totally screwed or do I have to let it run and charge for longer since battery was so dead ?

[@ItsBboyty1223]

@@vincehenriquez680 What people don't understand is it all depends how dead the battery is. To startup the car the battery must be at least 12 volts or higher. If below then chances are you'll need a jump. If the battery is around 1 - 2 volts (leaving lights on or door ajar overnight) then you'll have to leave it on much longer or best is to drive it on the freeway for a good hour or two. I do batteries for AAA tech and I had many members called back for service because the 30 - 40 minute runtime wasn't enough. The guy's video battery doesn't seem to be dead at all so 30 minutes is more than enough to recharge it.

[@EpicsodeOne]

The car starts eventually but the video doesn't start.

[@pandamant666]

I have my GLC parked for 3-4 months, and of course the battery dead, I jump start it yesterday and let the engine on for about 30mins, and once I turned off the car, the battery still dead, I tried jump start again today, and I drives it for about 30mins and also let it parked with engine on for 30mins, and when I turned it off and the battery still dead. Not sure if the battery can’t recharge anymore cuz it been parked for 4months

[@ItsBboyty1223]

How old was your battery when it happened? The older the battery, the older the cells and their lifespan depends on being fully charged. Let's say leaving 5 year old battery dead for months can weaken it and it may not hold a charge anymore. What people don't understand is it all depends how dead the battery is. To startup the car the battery must be at least 12 volts or higher. If below then chances are you'll need a jump. If the battery is around 1 - 2 volts (leaving lights on or door ajar overnight) then you'll have to leave it on much longer or best is to drive it on the freeway for a good hour or two. I do batteries for AAA tech and I had many members called back for service because the 30 - 40 minute runtime wasn't enough. The guy's video battery doesn't seem to be dead at all so 30 minutes is more than enough to recharge it.

[@mzhou05]

3 week the battery went to critical? My 2010 stay in my garage for over 3months (since early April), the batter is 10% only but can start the car with out issue. Idling for 15min now is 20% :)

[@ABAUTOAMG]

My dash cam has a parking record feature that records till the battery hits 40% then cuts out. Very handy to have when in public car parks. But not ideal during the lockdown :)

[@shaunmorris8176]

I just realised my car went flat after not running it for 7 days.

[@ABAUTOAMG]

Sorry to hear Shaun. It shouldn’t go flat that quickly! Sounds like you may need to swap to a new battery unfortunately.

[@tajdidajman4889]

didnt start it in more like 3 months lol

[@Musicmanrobert]

Ok I do not drive my car due to not passing inspection. It has a new battery. I start it 2 times a week for 15 mins. I forgot to do so recently and it was dead after a week. I have a Chevy not a high in car like yours.

[@frankmontez6853]

Charging Walmart valuebattery and while taking it out noticed a couple of things loose. I'll give it a lil time then try again. I bought one with Lil less CCA than the other one. CCA 540 instead of 585 . Might that be a problem ?

[@andre6746]

Mine was in critical today! Drove it 5-6 minutes to work. Started the car after work and battery was partially charge but my power mirror started folding and unfolded while I was driving!! Did that happen to your car or anyone you know? Please help with some advice.

[@ABAUTOAMG]

Hey Andre, Sorry I've never experienced this myself. I recommend getting it looked at by Mercedes or a goos independant mechanic as soon as you can.

[@andre6746]

@@ABAUTOAMG Yes was planning to do that on Monday but it seems fine for now I guess. Do you have a battery charger that you’d recommend for a Mercedes? Battery been partially charged even when I’ve been driving everyday since I got my car 1.5 weeks ago.

[@sanmarip6993]

sounds like you need a Car Exorcist for this problem...

[@jjsundra3310]

It al depends on how much life your car battery has...! A car battery coming to the end of its life will /may need a lot more hours ...! My experience is if you can get your car engine running at 1.5 ×1000 RPM a minute (normal is. 0.8 ×1000) for just 15 --30 minutes.., then your car battery will reach a sufficient - to - max charge)..! I use a flexible rod and place them between the accelerator and the seat...! It's easier to adjust the RPM that way then if one were to use a stiff rod..! Good day..!

[@ABAUTOAMG]

Thanks Sundra, useful info to know! My battery is pretty new so it worked well here.

[@jameswan670]

Just 30min to full charge?

[@bobbauldock3846]

Hey got a 2017 CT6Caddy, more Electric than frankinstine, I had to get a Trickle Charger, at the end of the day Battery should be no lower than 80% charge, ok 75 % man you are push,n it any lower at the end of the day something is wrong in the charge,n system or God forbid a short, Please do not play with electrics, you can loose it all, so be safe, and the best to you all. BB

[@funstuff2008]

Yeah my Mazda3 died the two weeks I was in quarantine.

[@fabianweber6937]

My mazda 3 still works the same as when i got it back in 2006 😁 imo one of the hardest cars to kill ever.

[@nirobthetaurra8521]

did you started after day?

[@funstuff2008]

@@nirobthetaurra8521 The battery was bad

[@wholovesorangesoda4696]

Why sport plus mode?

[@ABAUTOAMG]

Engine idles at slightly higher RPM which I was hoping would help :)

[@daveninjaneuro7089]

Bad test for one reason; your car is above idle. Seems like a bad video mate. Glad you recovered from covid though.

[@ABAUTOAMG]

Thanks Mate, I completely agree I wish they were more open about it all. The car will still be amazing but it will be shame to miss a few of these nice features. I'm still hyped though!

[@panagiwtisleousis8991]

Don’t you have the stand by mode on your car?

[@ABAUTOAMG]

Car batteries of this capacity will always loose there charge overtime if not used unless hooked up to a type of garage charger etc.

[@elixier33]

Most vehicles will not charger idle and not only that car batteries are extremely big it takes more than 20 minutes or half an hour to charge a car battery you could be looking at several hours from an alternator and some cars could take more than 5 hours if the battery is quite flat if it is very flat I wouldn't even recommend charging it from an alternator at all because it could destroy it so the reality is you should use a dedicated charger if you think that your battery or your car is going to be left for a long period of time. I absolutely do not recommend charging your battery from flat from your alternator put it under an awful lot of stress and can cause premature failure innkeeper cars and bikes

[@Hazulkar]

Recovered from what?

[@ABAUTOAMG]

Covid, we think. I'm all ok now though :)

[@Hazulkar]

@@ABAUTOAMG Oh, I see. Congrats.

[@marcelspence7228]

Disable the no lock key setting when you let your car idle, Mercedes owner, smh

[@AtticTapes14]

Steering on the right? It ain't the usa then

[@ABAUTOAMG]

Yep! Across the pond in England :)

[@MarcusLeonard307]

This feature of these cars is totally ridiculous and foreign to me. Pretty annoying.

[@Alycanj]

this is more bs about your car than you answering the question, I wasted 2:46 doing the tour of you car will waste no more!!

[@toughguy1125]

If you're in London, aka Londanistan definitely don't start your car without being In it. My mate had his car nicked by a couple Englishmen named Mohammed. Western civilization is canceled.

[@sko1beer]

Have the car wrapped in bacon

[@paimei26]

white people dont steal at all do they ?