Phone charged through my car blows through battery quicker?

[fuzzybabybunny]

I've noticed something very strange for years now, on multiple different smartphones.

I charge my phone to 100% via a 1A USB car charger.

I charge the same phone to 100% via a 1A wall outlet charger.

The phone charged to 100% from the car blows through battery life at a much faster rate than the one charged to 100% from the wall outlet.

Has anyone else noticed this?

 

[WelshBloke]

Has anyone else noticed this?

I'd have to say no.

Ampere-hours are Ampere-hours, they don't come in different flavours or diet versions AFAIK.

 

[fuzzybabybunny]

I'd have to say no.

Ampere-hours are Ampere-hours, they don't come in different flavours or diet versions AFAIK.

Well, not exactly. For instance phones quick-charged will not last as long as phones charged at a slower pace. It doesn't seem to apply in this situation though - maybe something to do with DC vs AC, stepping down from 12V versus 110V, pure sine wave in the home versus stepped wave, etc?

 

[WelshBloke]

For instance phones quick-charged will not last as long as phones charged at a slower pace.

Eh? Why wouldn't they last as long once charged up? The energy is being stored in the exact same way. In fact the stored energy is identical.

It doesn't seem to apply in this situation though - maybe something to do with DC vs AC, stepping down from 12V versus 110V, pure sine wave in the home versus stepped wave, etc?

The only thing I could see those affecting would be charge time. Once the energy is in the battery its all the same.

 

[Piroko]

All current phones get charged at 5V DC (USB spec) with 1A to 2.5A. As such, if the temperature of your battery at the end of charging is similar then it'll have the same total energy stored.

I'd rather look at your phone's bluetooth, perhaps it doesn't decouple from your car properly. That would be a very noticeable battery drain.

 

[pcgeek11]

I have noticed that when I charge my phone from a PC USB it does last quite a bit longer than if charged by a wall wart. I'm taking a day or two longer.

 

[nerp]

Imaginary or circumstantial. People experience this with cars, thinking certain brands of gas give them better mileage, for example. What is actually happening is that they are driving more conservatively and subconsciously squeezing out extra mileage. You probably are looking/using your phone more after the car charge, causing it to deplete more rapidly.

If you need to prove this to yourself, run some scientific tests. You'll see.

 

[notposting]

What is a car charger or wall charger?

Do you mean 12 VDC or 120 VAC chargers?

They both work in the car, so not sure what you mean?

 

[paperwastage]

do you charge it to 100% and wait at least 30 minutes? (for both cases?)

phone may report 100%, but it may still be trickle charging a little after that. the last 10% takes the longest

 

[3chordcharlie]

Crappy chargers can cause some phones to act up, and even make them unusable while plugged in, but I have no actual evidence that the resulting charge is less complete.

 

[ChronoReverse]

do you charge it to 100% and wait at least 30 minutes? (for both cases?)

phone may report 100%, but it may still be trickle charging a little after that. the last 10% takes the longest

This is most likely what's going on if it's not just placebo effect.

 

[jchu14]

Another possible explanation is that if you're charging in the car, there's a better chance that you're using the phone for music streaming or navigation. So you could be blowing through the first 10 or 20% of the battery charge without really thinking about it.

 

[Midwayman]

Only thing I can think of is if the voltage on the car isn't stable it might be tripping the charge cutoff with its peak voltage even if RMS is similar.

 

[Yuriman]

Another factor is the location of your phone. A weak cell signal will eat through your battery.