Thing pulls less than 1 amp
Don't use your car to charge your smartphone
- Thread starter supton
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My truck has like a 165 amp alternator, might as well use it.
I'm amazed that so many of you take the information as personal criticism. It's obvious that the energy comes from gasoline and it's a simple calculation that anyone can make, even if it's an inconsequential cost.
We only charge our phones at home, thereby eliminating unnecessary and dangerous fossil fuel consumption.
Or in the "zero emission" Tesla.
Or in the "zero emission" Tesla.
Of course, it only makes sense.
Oh, wait....
Originally Posted By: splinter
We only charge our phones at home, thereby eliminating unnecessary and dangerous fossil fuel consumption.
Oh, wait....
Originally Posted By: splinter
We only charge our phones at home, thereby eliminating unnecessary and dangerous fossil fuel consumption.
Do this: in order to compensate for the horrific electrical drain a cell phone inflicts, and the horrific 0.03% MPG hit, just air up your tires 2 PSI all the way around. You probably gain 1 MPG, which is 33X what you "lost" due to charging the cell phone, LOL.
I charge my phone at work.
I crunched the numbers when gas was $3-4 and a cell phone charger is 10 to 15x more expensive than shore power. So would be a home generator, for that matter.
Anyone who runs a 5 gallon tank generator during a power outage with a kill-a-watt meter attached will know their own efficiency, as in, how many kilowatts they get from a tank of gas. A car's alternator shouldn't be much different. To even rough it in, it's not hard to imagine consuming 5-10 gallons of gas in a day, and paying $100 a month for utility power.
I crunched the numbers when gas was $3-4 and a cell phone charger is 10 to 15x more expensive than shore power. So would be a home generator, for that matter.
Anyone who runs a 5 gallon tank generator during a power outage with a kill-a-watt meter attached will know their own efficiency, as in, how many kilowatts they get from a tank of gas. A car's alternator shouldn't be much different. To even rough it in, it's not hard to imagine consuming 5-10 gallons of gas in a day, and paying $100 a month for utility power.
Originally Posted By: Joel_MD
Originally Posted By: hattaresguy
...the load on an alternator for something super low voltage like a phone is just negligible.
Yes, definitely.
When you drive your car, the electrical system is probably drawing between 40 and 80 amps to run the ignition, headlights, HVAC, stereo, etc. In the article the retired GM guy said the average smartphone needs about 4.8 watts to charge. At 14 volts that is about 0.35 amps. The difference between a 50-amp load and a 50.35-amp load would be negligible when you're driving an alternator that is only 60% efficient, turned by a 200hp gasoline engine that is only around 30% efficient.
I think I'll lose 0.03 minutes of sleep tonight over this issue.
Just to be clear the newer devices using qualcomm quick charge 2.0 draw 18 watts, although most earlier androids and newer low end ones use the 5 watt chargers still. Some are in between at about 11-12 watts of they accept the 2.1 amp current
Originally Posted By: hattaresguy
...the load on an alternator for something super low voltage like a phone is just negligible.
Yes, definitely.
When you drive your car, the electrical system is probably drawing between 40 and 80 amps to run the ignition, headlights, HVAC, stereo, etc. In the article the retired GM guy said the average smartphone needs about 4.8 watts to charge. At 14 volts that is about 0.35 amps. The difference between a 50-amp load and a 50.35-amp load would be negligible when you're driving an alternator that is only 60% efficient, turned by a 200hp gasoline engine that is only around 30% efficient.
I think I'll lose 0.03 minutes of sleep tonight over this issue.
Just to be clear the newer devices using qualcomm quick charge 2.0 draw 18 watts, although most earlier androids and newer low end ones use the 5 watt chargers still. Some are in between at about 11-12 watts of they accept the 2.1 amp current
Originally Posted By: Kiwi_ME
I'm amazed that so many of you take the information as personal criticism. It's obvious that the energy comes from gasoline and it's a simple calculation that anyone can make, even if it's an inconsequential cost.
Exactly. Considering the power obtained from gasoline in a car is probably less than 50% efficient as the electricity in your house it makes sense not to charge it from your car.
Sure its negligible on an individual basis. But you are an engineer like me and facts are just that to us...facts...lol.
I'm amazed that so many of you take the information as personal criticism. It's obvious that the energy comes from gasoline and it's a simple calculation that anyone can make, even if it's an inconsequential cost.
Exactly. Considering the power obtained from gasoline in a car is probably less than 50% efficient as the electricity in your house it makes sense not to charge it from your car.
Sure its negligible on an individual basis. But you are an engineer like me and facts are just that to us...facts...lol.
Originally Posted By: Al
Originally Posted By: Kiwi_ME
I'm amazed that so many of you take the information as personal criticism. It's obvious that the energy comes from gasoline and it's a simple calculation that anyone can make, even if it's an inconsequential cost.
Exactly. Considering the power obtained from gasoline in a car is probably less than 50% efficient as the electricity in your house it makes sense not to charge it from your car.
Sure its negligible on an individual basis. But you are an engineer like me and facts are just that to us...facts...lol.
The issue I have with his whole attention grabbing article.. is... Most cars are not designed AT ALL to be energy efficient.
All incandescent light bulbs. DRL lights. etc.
Then of course you have inefficient blower motors and many other places they could save quite a few watts.
but we are going to worry about a car charger that uses between 5watts and 18 watts(max)
Better give all those "tools" who drive with their headlights and foglights on constantly a swift kick in the butt.. they are wasting 150w right there.
I see the basic premise of the article but if you look at it with common sense its totally ridiculous.
Whats next not running the defroster and driving at night with your lights off.. Driving in the rain with no wipers
(oh wait all that happens in china already
)
Originally Posted By: Kiwi_ME
I'm amazed that so many of you take the information as personal criticism. It's obvious that the energy comes from gasoline and it's a simple calculation that anyone can make, even if it's an inconsequential cost.
Exactly. Considering the power obtained from gasoline in a car is probably less than 50% efficient as the electricity in your house it makes sense not to charge it from your car.
Sure its negligible on an individual basis. But you are an engineer like me and facts are just that to us...facts...lol.
The issue I have with his whole attention grabbing article.. is... Most cars are not designed AT ALL to be energy efficient.
All incandescent light bulbs. DRL lights. etc.
Then of course you have inefficient blower motors and many other places they could save quite a few watts.
but we are going to worry about a car charger that uses between 5watts and 18 watts(max)
Better give all those "tools" who drive with their headlights and foglights on constantly a swift kick in the butt.. they are wasting 150w right there.
I see the basic premise of the article but if you look at it with common sense its totally ridiculous.
Whats next not running the defroster and driving at night with your lights off.. Driving in the rain with no wipers
(oh wait all that happens in china already
)That's 158 feet !
It always cracks me up when non-technical web- or magazine-article writers "discover" conservation of energy (or when they forget it and argue that charging your phone, or worse an electric car, is "free").
Of COURSE every darn little electrical load you turn on in the car requires a little bit of gasoline from the tank to run it. But if you didn't charge your phone in the car, you'd charge it on the electrical grid and *that* would take a few more lumps of coal dust per hour per phone burned at the power plant, or a few more atoms fissioned per hour per phone, or a little more water released downstream per hour per phone. Every joule of energy we use *anywehere* comes from *somewhere*, and then eventually winds up as heat released into the atmosphere and radiated away into space.
Of COURSE every darn little electrical load you turn on in the car requires a little bit of gasoline from the tank to run it. But if you didn't charge your phone in the car, you'd charge it on the electrical grid and *that* would take a few more lumps of coal dust per hour per phone burned at the power plant, or a few more atoms fissioned per hour per phone, or a little more water released downstream per hour per phone. Every joule of energy we use *anywehere* comes from *somewhere*, and then eventually winds up as heat released into the atmosphere and radiated away into space.
After reading the original article, its title should be changed to Using a Smartphone While Driving Isn't as Free as You Think.
Charging isn't the problem, using a phone as an internet hot spot might be:
Quote:
To make his calculation, Bereisa assumed that a typical smartphone connected to WiFi or the Internet needs about 4.8 watts of energy to charge in a car. (Delphi estimates that some less-efficient models draw twice that amount.)
Despite Bereisa's background, I am very skeptical of his methodology, and suspect that the true load is closer to 10% of his estimate — if that.
Since I have a $15 dumb flip phone, which will run for 10 days on a charge, this news isn't going to change my driving habits at all.
Charging isn't the problem, using a phone as an internet hot spot might be:
Quote:
To make his calculation, Bereisa assumed that a typical smartphone connected to WiFi or the Internet needs about 4.8 watts of energy to charge in a car. (Delphi estimates that some less-efficient models draw twice that amount.)
Despite Bereisa's background, I am very skeptical of his methodology, and suspect that the true load is closer to 10% of his estimate — if that.
Since I have a $15 dumb flip phone, which will run for 10 days on a charge, this news isn't going to change my driving habits at all.
Last edited:
Originally Posted By: Rand
The issue I have with his whole attention grabbing article..
The primary purpose of the article is to expose you to the ads, but you knew that.
But, irrespective of the phone charging example selected, if reading the article also makes you think more about the sources, conversions and usage of energy, then all the better.
The issue I have with his whole attention grabbing article..
The primary purpose of the article is to expose you to the ads, but you knew that.
But, irrespective of the phone charging example selected, if reading the article also makes you think more about the sources, conversions and usage of energy, then all the better.
Originally Posted By: 440Magnum
It always cracks me up when non-technical web- or magazine-article writers "discover" conservation of energy (or when they forget it and argue that charging your phone, or worse an electric car, is "free").
Of COURSE every darn little electrical load you turn on in the car requires a little bit of gasoline from the tank to run it. But if you didn't charge your phone in the car, you'd charge it on the electrical grid and *that* would take a few more lumps of coal dust per hour per phone burned at the power plant, or a few more atoms fissioned per hour per phone, or a little more water released downstream per hour per phone. Every joule of energy we use *anywehere* comes from *somewhere*, and then eventually winds up as heat released into the atmosphere and radiated away into space.
The problem with these physics arguments is that car is far far from an ideal system. The vast majority of Joules is wasted already and that a car is only 15% or 20% efficient. A lot of it is use-it or lose it anyway and don't have an additional cost if you use it.
Take for example your cabin heater and catalytic convertor. The heat used for those systems are basically "free"
It always cracks me up when non-technical web- or magazine-article writers "discover" conservation of energy (or when they forget it and argue that charging your phone, or worse an electric car, is "free").
Of COURSE every darn little electrical load you turn on in the car requires a little bit of gasoline from the tank to run it. But if you didn't charge your phone in the car, you'd charge it on the electrical grid and *that* would take a few more lumps of coal dust per hour per phone burned at the power plant, or a few more atoms fissioned per hour per phone, or a little more water released downstream per hour per phone. Every joule of energy we use *anywehere* comes from *somewhere*, and then eventually winds up as heat released into the atmosphere and radiated away into space.
The problem with these physics arguments is that car is far far from an ideal system. The vast majority of Joules is wasted already and that a car is only 15% or 20% efficient. A lot of it is use-it or lose it anyway and don't have an additional cost if you use it.
Take for example your cabin heater and catalytic convertor. The heat used for those systems are basically "free"
Don't charge it in the car & save a few pennies. Better yet, toss the phone out the window to lighten the load the car has to haul and maybe save another penny.
Or use the phone while driving, tailgate real close to big rig to lessen headwind to increase mpg.
Or use the phone while driving, tailgate real close to big rig to lessen headwind to increase mpg.
Originally Posted By: Errtt
Don't charge it in the car & save a few pennies. Better yet, toss the phone out the window to lighten the load the car has to haul and maybe save another penny.
Or use the phone while driving, tailgate real close to big rig to lessen headwind to increase mpg.
Or lose 10 pounds, that should do it too.
Don't charge it in the car & save a few pennies. Better yet, toss the phone out the window to lighten the load the car has to haul and maybe save another penny.
Or use the phone while driving, tailgate real close to big rig to lessen headwind to increase mpg.
Or lose 10 pounds, that should do it too.
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