[Motorola Droid RAZR] brainwash123:
I've touched on the other issues in a PM.

Regarding battery charging there are a lot of misconceptions circulating on the Internet so I'll try to provide some explanations.

"A stronger USB charger damages the device"

Wrong: the device will always pull up as much as it needs, at least a nicely designed one. Most (All) smartphones are able to do that. Some dumb USB devices like cheap Chinese AA/LiPo chargers might have some problems with that if current limiting is not built in properly. I have yet to see such a case.

Okay, Apple might be an exception to that rule but it still abides to the standard 100/500mA charging current.

"Stronger" means that the current that can be supplied from the charger is higher. They all MUST limit the charging voltage between 4.45 and 5.25V. Going above that voltage is what damages the device, not the current.

Think of the charger as the (constant) water supply, the cable as the garden hose and the phone as the sprinkler. The phone controls how much it sprinkles on the lawn (battery). A thin water hose will be able to deliver less water. Some cheap/fake USB lead cables use very thin wires inside.

"Using a USB charger from another company will damage the device "

Wrong, most of the time.

Using a brand-name charger will certainly not damage the device. However, cheap (all) clones of Apple chargers are most likely to damage smartphones because they put out peaks of higher voltages (I've seen 10V) and are not able to regulate the supplied voltage and current properly. You can spot them if your capacitive touchscreen seems glitchy and touches are random. Capacitive touchscreens are very sensitive to electrical noise.

Using Kill-a-watt or similar devices to monitor charging current

Mostly wrong because a charger is not 100% efficient and you are measuring input current (at 110/220V) instead of the output one (at 5V). Charger efficiency also varies with load. The charger might say 220V/100mA input, 5V/500mA output. That means that 22W might go in but only 2.5W go out. Well, obviously it's not going to be like this, but it might be something like 3W in and 2.5W out.

Leaving the charger plugged into the phone damages it

Not decided, but the reason behind this is mostly wrong.

The charger supplies power to the phone at all time but the phone is able to decide how much power it needs. A well designed phone battery circuit will only charge when needed and then require no further current. A badly designed charging circuit (inside the phone) will overcharge the battery or ignore how hot it is, killing the battery in time.

Using logcat you are able to monitor how much your phone is drawing from the charger by searching for "set_charge_current".

How does the charger tell the phone available current? The USB plug inside the charger has various voltages/resistors on the D+ and D- pins. No signal on D+ and D- means that it can only provide 100mA. If D+ and D- are shorted then the charger can provide 500mA. I don't know the rest. The computer talks to the phone directly.

http://en.wikipedia.org/wiki/Universal_Serial_Bus#Charging_ports_and_accessory_charging_adapters

What if the charger says it can give out xxx mA but cannot physically do this? If the requested charging current exceeds the hardware capabilities then the voltage from the charger will drop under the USB spec (under 4.45 something volts). A well designed phone will just request a smaller and smaller current until the charger is able to supply enough voltage. iPhones just give up.

Other issues: a badly designed charger (white generic ones) will overheat, might catch fire and burn your house down, might put up 110/220V through your phone, adds noise on the line causing noise on TV and speakers (high EMI), makes your touchscreen impossible to use. Throw them away at first sight.

Back to RAZR, here is what my phone is able to draw from various chargers:

- Sony [something]Watch charger: 100mA. It says 500mA on the plug but does not have D+/D- shorted. Assuming a flat battery it would take at least 22h to charge the RAZR.

- USB2.0 computer port: 500mA.

- USB3.0 computer port: 700mA. It can be anything between 500 and 900mA

- HP Touchpad charger and cable: 1800mA.

- I don't have the moto charger at hand

Also, the charge current goes down as the battery level (or temperature) goes up. Until 80% or so it will draw the maximum but then it will taper down.