[donjacob]

Had this experience back in 2020 while I was waiting in a parking lot. Turned on the a/c blower and sat inside the car. Battery drained out in a few minutes and my baleno struggled to crank. Fortunately since I was in the city , called MOS , they came and jump started the car. Paid them 600 rupees. Car was 3 years old with the stock battery. That battery served me well for two more years till 2022.
Lesson learnt: Do not keep your blowers running with the car off for saving fuel, it's not worth the hassle in case of a battery drain.

[alphamike_1612]

Couldn't the car be push started if the battery has drained? (If it's a manual)
Is there any reason why no one has suggested it?
Both the OP and a lot of the other posters who have posted their experiences also talk only about jump starting the car and not push starting it.

Are there any obvious drawbacks that I'm missing? Asking because push start would be the first thought to occur to me and not jump start.

Originally Posted by Jeroen

When the engine is switched off it is impossible to use the AC. The AC compressor is run, via a belt off the engine pulley. Ergo, if the engine isn’t running, your AC can’t be running.

But, when I was a mischievous child and young adult, I have several times done the evil act of switching on the A/C when the ignition is not on and have always been treated to the wave of cold air for a full minute before some adult spots it and switches it off.
How/Why does this occur?

alphamike_1612

[som9729]

Originally Posted by blitz_nomad

Any advice?

Thanks for reading!

Yes, running the blower can drain the battery.
Generally, for an ICE car, one can't actually run the compressor when the engine is off.
Can't comment on a TATA punch if it has some such new feature.

Drawing from my experience of owning 2 Tata Indigos, a Etios & a Ritz over the past 20 years, I've had many situations where I've slept in the car, or was waiting for someone and had the blower running for 30-45mins or more at times.

I've never faced the issue of battery draining.
Especially for a brand new car, that's just weird.

Either quality of the battery is in question, or charging of the battery is not properly happening.

Have the battery checked & confirm (from the ASS) that the battery is being charged.

[AdityaRai]

I believe you left the key in the "ON" position rather than "ACC" position, as the Blower/Power-windows do not run on the ACC position.

Any vehicle's electrical systems are designed based on priority of load draw, and different fuses/fuseboxes are powered at ACC vs ON postion. ON position assumes that the engine is running (as this is a position the key would default to after cranking of the engine).

The battery can last for over an hour in the ACC position as this only powers the audio system and the 12V power outlet (assuming you do not have headlights+tailights on, which have the capability to stay on even without the key inserted- this is by global regulations- so that a broken down vehicle can have lights running on a dark highway).

The battery wont last more than a 15-30 mins on the ON position, as it is powering the following assuming that the engine is supplying power:
1) MPFI fuel pumps (run continously at high pressure)
2) Ingition coils (since the Punch is a petrol vehicle)
3) Power window circuits
4) Electrical Radiator fans (depending on coolant temperature)
5) All engine/exhaust and coolant sensors (entire OBD system)
6) All safety equipment sensors (ABS, Airbags, fluid levels)
7) The AC circuits, including all sensors, and last but not the least, the high powered blower motor

Thus, its advised to never leave a vehicle in the ON position if there isn't an intention to turn the engine on (either by cranking, pushing, jump starting or cranking by releasing the clutch on a stalled engine when the vehicle still has significant speed on the road).

ACC position may be used to listen to music and use the 12V socket for charging your phone, but this too is best avoided.

Please remember that the Lead Acid Battery in your vehicle is there to serve only one purpose: Bringing the Gasoline Engine to life, after which, all your energy needs are to be met by the gasoline engine.

[NB_4763]

Originally Posted by blitz_nomad

To my utter horror, this time the car wouldn't start. It's a new car, less than a year still and up to date, I've had zero problems with it. It kept saying "smart key not in range". I placed the key right near the handbrake where it is supposed to be placed in case of low battery and it still kept saying smart key out of range, then suddenly that message disappeared and the accessories etc came to life. But the engine wouldn't crank. There was some knocking kind of sound (not from the engine but from the audio system) each time I tried to start the engine - there was also some sound like the car was ventilating and then it would simply not start. I then got a message in the dash - something along the lines of 'one-hour mode activated'.

The AC cannot run when the ignition is OFF. The blower was ON. In the ON position [Green light on the push button] Lights, Music system and the blower might have been running which is why your battery might have drained.

That "one hour mode" is for the infotainment system. We can listen to music for one hour with the ignition OFF after which it will prompt you to Turn on the Ignition to continue [Shows the warning in the Infotainment system].

In the instrument cluster for Altroz ,Punch [Top model] whenever ASS is enabled and you car shuts off there are few conditions after which the car will turn on automatically without manually pressing the clutch [These prompts will be shown in the Instrument cluster]

1- High cabin temperature (Self explanatory).
2- Brake vacuum pressure low (If you are on a slope with your foot on the brake pedal).
3- Battery Voltage low (When all electricals are ON. For example lights).

I think push starting the car would have fired it right up . [But it is hard to do without help].

[audioholic]

It's a good idea to let the engine running in these conditions. Modern cars have a huge electrical load when switch is in the ON position and maybe half of it in ACC position and these can drain the battery pretty early. Especially if it's an AMT car the AMT oil pump keeps running every minute or two and is a heavy consumer of battery. Hence it will drain the battery pretty quickly.

On long trips I do not switch the engine off unless the car will be empty and locked. Otherwise even during short breaks if someone is in the car I keep the engine running at least to keep AC on and car cool. Especially if there is a sensitive situation like having a family member who has to remain in car, its better to spend a liter of petrol an hour for their comfort than end up in a demanding situation or to let them stay in the car without AC.

[vijaysrk]

Originally Posted by arijitkanrar

Looks like the AC in ignition drained the battery. And low battery caused all the weird sorts of errors that you saw.
I suggest you leave your engine on if you need to use the AC with people inside. The fuel consumption will be negligible without load on the engine.

Many asked if a car battery can power the AC without engine running. I'm not sure of Tata Punch but our Ford Figo can and does run the AC with Ignition On without engine running.

However our SA had explictly mentioned not to do this as it can very quickly drain the battery.

Never owned (or even driven) a Figo, but I would be VERY surprised if there's any car ICE sold in India that can run the AC without the engine running!

Just to illustrate with numbers, a typical car AC compressor consumes a few kilowatts of power. Assuming for the sake of argument that the one on the Figo consumes just one kilowatt (a BIG underestimate), and assuming a battery capacity of 50AH or thereabouts, it would indicate a total battery capacity of 600 WH (50AH times the battery voltage, 12V). Now, even with the compressor being the only load(which is never the case), that gives a theoretical runtime of just 36 minutes. Now that's not counting the AC blower, all the other electronics, the ignition system etc. No reason to jump through so many hoops for a few minutes of AC runtime...

IMHO, there's no reason to have an electrically powered AC compressor in an ICE car and pay for the conversion losses twice (from mechanical to electrical, then back to mechanical again!), only to eek out a few minutes of AC compressor runtime, when a belt & pulley coupled (and clutch actuated) AC compressor works just fine!

[raju2512]

I had a Figo for 12 years and AC doesn't run when the engine is not running.

If blower is running for say about 10-15 mins it won't drain the battery dead. It would be probably close to an hour . In such conditions the first try is push start. Change the battery as soon as possible. You don't have to worry about other electricals or the wiring. But check once if the alternator is ok and is charging the battery correctly

[balenoed_]

Originally Posted by arijitkanrar

...but our Ford Figo can and does run the AC with Ignition On without engine running.

How is this possible? The compressor is driven by engine, right? You must be referencing to fan blower.

[Jeroen]

Originally Posted by AdityaRai

Any vehicle's electrical systems are designed based on priority of load draw, and different fuses/fuseboxes are powered at ACC vs ON postion. ON position assumes that the engine is running (as this is a position the key would default to after cranking of the engine).

The battery wont last more than a 15-30 mins on the ON position, as it is powering the following assuming that the engine is supplying power:
1) MPFI fuel pumps (run continously at high pressure)
2) Ingition coils (since the Punch is a petrol vehicle)
3) Power window circuits
4) Electrical Radiator fans (depending on coolant temperature)
5) All engine/exhaust and coolant sensors (entire OBD system)
6) All safety equipment sensors (ABS, Airbags, fluid levels)
7) The AC circuits, including all sensors, and last but not the least, the high.

Although there could be difference between various cars I don’t believe this is true at all. Most ignition and electronic systems I have worked on do things quite a bit different.

Most have various relais build in so as not to power any major electrical supplies, certainly not during cranking. Most high draw systems only get powered up after the engine not only cranks, but actually fires. Both high and low pressure fuel pumps typically don’t run with the ignition on. You might hear them initially, but as soon as pressure has been build in the system they will stop until the engine fires.

The catalytic converter won’t be powered until the engine fires. Yes, most sensors are powered, but that is a very low draw. Cooling fan are usually switched via a thermostat, so if the engine is cold they will not be powered. But for instance the electric cooling pump on my Jaguar super charger is powered as soon as you turn the ignition on.

In general, just because something has power doesn’t necessarily mean it draws power from the battery. Unless you open and close an electrically operated window, the current within the circuit is just about negligible. If circuits are operated by switch you have no electrical draw at all, until the switch closes.

Let’s assume you a 60amphour battery. That means you can draw 60Amps for an hour. Really, there are no cars that will draw that sort of power when the ignition is on.

I actually did a number of measurements on my Jaguar not so long ago. Now my Jaguar is absolutely filled to the brim with electronic stuff. There are more fuss boxes and relais and computers everywhere than you can shake a stick at.

Even so, I only got 4,7Amp as a draw with the ignition switched to ON. That was just 1A higher than on ACC. Even on that 60Amp hour battery it would last for some 16 hours. You can read about it here:

https://www.team-bhp.com/forum/techn...te-drains.html (Dealing with Electrical parasite drains)

If anybody has any actual measurements of battery drain in ACC and or ON position on various cars I will be happy to accept them. Seriously, whether in ACC or ON position if your battery is drained within an hour to the point where the engine won’t start there is something amiss with your battery and or electrical system.

[AdityaRai]

Originally Posted by Jeroen

Although there could be difference between various cars I don’t believe this is true at all. Most ignition and electronic systems I have worked on do things quite a bit different.

Most have various relais build in so as not to power any major electrical supplies, certainly not during cranking. Most high draw systems only get powered up after the engine not only cranks, but actually fires. Both high and low pressure fuel pumps typically don’t run with the ignition on. You might hear them initially, but as soon as pressure has been build in the system they will stop until the engine fires.

But for instance the electric cooling pump on my Jaguar super charger is powered as soon as you turn the ignition on.

In general, just because something has power doesn’t necessarily mean it draws power from the battery. Unless you open and close an electrically operated window, the current within the circuit is just about negligible. If circuits are operated by switch you have no electrical draw at all, until the switch closes.

Even so, I only got 4,7Amp as a draw with the ignition switched to ON. That was just 1A higher than on ACC. Even on that 60Amp hour battery it would last for some 16 hours. You can read about it here:

https://www.team-bhp.com/forum/techn...te-drains.html (Dealing with Electrical parasite drains)

If anybody has any actual measurements of battery drain in ACC and or ON position on various cars I will be happy to accept them. Seriously, whether in ACC or ON position if your battery is drained within an hour to the point where the engine won’t start there is something amiss with your battery and or electrical system.

I completely agree with you. The only additional draw here would be the AC Blower (guessing it to be 10-12W, so around 1Amp more) and music/lights if any.

I was just trying to highlight and disuade a practice I have commonly seen in India, where drivers leave the vehicle in the "ON" position for prolonged periods of time (with all the Tell-tale lights light up on the dash). This is usually to provide the comfort of the blower to the passengers and allow the operation of power windows.

This view might be personal (and I am open to learning from others), but I recommend never leaving the vehicle in ON unless one intends to start the engine. I don't see the benefits of doing so outweighing the risks.

[Neversaygbye]

Originally Posted by blitz_nomad

A few questions linger in my mind regarding the car - was the whole thing caused because I let the A/C run with the ignition off for about 10 mins? Considering it's a new car, I'd have expected at least a low battery warning in the dash but nothing like that showed up until it suddenly died altogether. I will indeed get it checked fully at the service center again, but any thoughts on the check engine lamp and abs lamp that was on for a while? If it was indeed a low battery thing, what are the chances of that occurring again. Any advice?

I think that you have already got a lot of advice from others and also the root cause has been properly identified, but one point that struck me was that the audio system was in on mode when you tried starting the car. While this is usually not an issue, it is still advisable to check that anything that can draw power from the battery is off, when you switch off the ignition. I once left my headlights on by mistake in my Matiz and the battery was completely drained when i got back in the evening (the car was in my office parking). Thankfully there was a Toyota showroom nearby and they helped to jump start my car. Anyway, it was a lesson learnt. Nowadays I ensure that I switch off the AC and blower (in that order), audio system and lights (if on earlier) before I leave the car. You can do the same. Also, please keep a jump start cable in the car - you never know when it will be of use. I have this one in my car:

https://www.amazon.in/gp/product/B07...e?ie=UTF8&th=1

[Jeroen]

Originally Posted by AdityaRai

This view might be personal (and I am open to learning from others), but I recommend never leaving the vehicle in ON unless one intends to start the engine. I don't see the benefits of doing so outweighing the risks.

I agree, that is what the ACC position is for.

Jeroen

[blitz_nomad]

Originally Posted by Jeroen

Yes, the AC blower tends to be powered in the ACC position and it draws quite a bit. But even in the ACC position and the AC blower on it would take many hours for a well charged battery to be drained.

If your battery drains in a matter of hours on ACC the first thing to do is to have the capacity of your battery checked. (Note, not just a voltage check, that is not good enoug)

Thank you. A total noob here, what does checking battery capacity entail? Is there some metric that I can ask the service center to note - just to be sure that they'd indeed done it and to get a sense of my battery's capacity?

Originally Posted by alphamike_1612

Couldn't the car be push started if the battery has drained? (If it's a manual)

It's an automatic. Push-button start. Even though I was parked in the leftmost lane, I did seek help and had a few come up and help push the vehicle to a corner spot. I didn't try to start the vehicle when it was being pushed. Perhaps I should have tried that. Strangely no one suggested it either.

Originally Posted by som9729

I've never faced the issue of battery draining.
Especially for a brand new car, that's just weird.

Either quality of the battery is in question, or charging of the battery is not properly happening.

Have the battery checked & confirm (from the ASS) that the battery is being charged.

Thanks for the tip. Will ask the service center to check for battery charging and parasite draws.

Originally Posted by AdityaRai

I believe you left the key in the "ON" position rather than "ACC" position, as the Blower/Power-windows do not run on the ACC position.

It's a push button start. I left it where the music system works, but the engine isn't powered on. I did have the music system playing from time to time. Coming to think of it, I also had my dashcam plugged into the 12V socket. It's a Viofo T130. But it doesn't power up unless the engine is on. If it was up indeed, it should have been recording - I'll check to double confirm. Now I'm worried that the service center will blame it on the dashcam. No hard wiring, it's just setup to plug into the 12V socket.

Originally Posted by NB_4763

That "one hour mode" is for the infotainment system. We can listen to music for one hour with the ignition OFF after which it will prompt you to Turn on the Ignition to continue [Shows the warning in the Infotainment system].

In the instrument cluster for Altroz ,Punch [Top model] whenever ASS is enabled and you car shuts off there are few conditions after which the car will turn on automatically without manually pressing the clutch [These prompts will be shown in the Instrument cluster]

1- High cabin temperature (Self explanatory).
2- Brake vacuum pressure low (If you are on a slope with your foot on the brake pedal).
3- Battery Voltage low (When all electricals are ON. For example lights).

I think push starting the car would have fired it right up . [But it is hard to do without help].

The car almost completely went dead after the "one hour mode". And it wasn't one hour, but rather happened in a few minutes after that message. It's a Punch AMT top variant. No Auto Start Stop.

Originally Posted by audioholic

Especially if it's an AMT car the AMT oil pump keeps running every minute or two and is a heavy consumer of battery. Hence it will drain the battery pretty quickly.

On long trips I do not switch the engine off unless the car will be empty and locked. Otherwise even during short breaks if someone is in the car I keep the engine running at least to keep AC on and car cool. Especially if there is a sensitive situation like having a family member who has to remain in car, its better to spend a liter of petrol an hour for their comfort than end up in a demanding situation or to let them stay in the car without AC.

It's an AMT indeed. I wasn't bothered about the fuel consumption at all, I turned off the ignition, mainly because I was leaving the car and thought it wasn't prudent to leave the engine on when the occupants don't know anything about the car.

One request: Would be nice to have a thread in the forum from experienced folks about Do's and Dont's when one is stranded on the highway.

[som9729]

Originally Posted by blitz_nomad

Thanks for the tip. Will ask the service center to check for battery charging and parasite draws.

1) Check battery charging and battery's practical capacity (I believe this is done by checking voltage, but I'm not an expert, so check other sources for this info)

2) Check for parasitic draws (which you've covered)

3) Check for bulges/damage to the battery & wiring etc.

4) If nothing else, check alternator functioning to ensure battery is properly getting charged.

5) Can't comment on AMT pump (audioholic's post above). I've only used manuals all along!


There's no way using just the fan for 30-45mins can drain a new car's battery.
Unless there's been a very drastic change in how the car works & technology which I'm unware of! (like the AMT motor???)

Also, my opinion - Amaron batteries are much better in quality & durability than their Exide equivalents.

And do keep us posted. Always interesting to figure out something new!