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.

[darwinismresearch-trolling]

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. 🙏🏼

[mr-dpc-]

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.

[Straker]

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!

[pfeamg]

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

[ahemgee]

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

[bartzeegers]

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

[albertl]

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

[reiannaidoo]

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.

[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 the cost of gas (petrol) these days, it may be more worthwhile to take a drive. of your car is beautiful. Would trade that for my graphite grey metallic.

[ESMorg]

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

[srgiosim]

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

[dawnsreviews]

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.

[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.

[dimeolas]

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.

[Drazorig]

Had this same issue during the first lockdown and 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.

[johnmachinmegavegan]

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.

[ChasedWheels]

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.

[stevepinder]

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.

[edwardedward]

Thanks for the very useful information Cheers Eddie