Car Charger Questions

[marine one]

I've dug through my assortment of micro usb car chargers trying to find one that will work best for the S4.
I have a motorola car charger that came with my Droid Bionic that, according to the Galaxy Charging Current Lite app, registers an output of 780mA. I also have a charger with an output 1200mA which is the same output of the OEM wall charger.
I rarely use a car charger, as I just don't find that I need them. I will however, be taking a 2,000+ mile road trip next month and will probably be doing some serious Pandora listening, so I want to have a car charger available.
Any thoughts on which charger should I use?

 

[Goodspike]

The one with the higher output.

If you have Amazon Prime (or can find it locally) you might want to consider buying this:

Amazon.com: PNY P-P-DC-UF-K01-GE 12 Volt 2.1 Amp Rapid USB Car Charger - Black: Electronics

Much more powerful, and small.

 

[lotus49]

The stock charger is rated at 2A and charges my phone at 1900mA so close enough.

There are plenty on eBay - just look for a current of 2A. It is worth investing in a high current one if you are using your phone a lot as some apps (eg satnav) use more power than some weedy chargers put out and the battery still runs down even though the phone is plugged in.

 

[marine one]

The one with the higher output.

If you have Amazon Prime (or can find it locally) you might want to consider buying this:

Amazon.com: PNY P-P-DC-UF-K01-GE 12 Volt 2.1 Amp Rapid USB Car Charger - Black: Electronics

Much more powerful, and small.

That does look good. Small size will be a big help as well. My one concern was that a charger with a high output could cause battery damage or otherwise shorten the battery life.

 

[Goodspike]

That does look good. Small size will be a big help as well. My one concern was that a charger with a high output could cause battery damage or otherwise shorten the battery life.

This is higher amperage, not higher voltage. The phone will not draw more amps than what it can handle. Think of it like a power supply on a desktop computer. You can have a 150 watt power supply or a 450 watt power supply, and that will not damage the computer. The 150 watt power supply may fail earlier, however, because it's more likely to be run at capacity. The 450 watt power supply would be less efficient. Neither of those concerns however would be much of a concern with a 1.2 to 2.1 amp 12 volt to 5 volt transformer/charger.

If it were higher voltage, that would be a concern, but (almost?) all USB is 5 volts.