Chargers

[Catlady]

Originally Posted by HarryT

In that case, no, a standard USB charger won't work.

What is telling you that? I don't even know what I'm looking at!

[Catlady]

Originally Posted by PeterT

See https://www.newegg.com/Product/Produ...9SIA2461JM2969

Sent from my Nexus 7 using Tapatalk

Thanks!

[HarryT]

Originally Posted by Catlady

What is telling you that? I don't even know what I'm looking at!

The "Output: 5V at 3A" is telling me that. A normal USB charger can't supply 3 Amps of current.

[theducks]

Originally Posted by Catlady

I have the T100TA-H1. It's got a micro USB, not a mini (I always confuse those).

The charger says:

That say you can plug it in almost any place in the world (with a prong adapter)
any voltage from 100 to 240
line frequency 50/60Hz (really is 50-60Hz)

The power draw is expressed in VA because of the wide input voltage spec
To get the current Current divide VA by the line (mains) voltage

[Catlady]

Originally Posted by HarryT

The "Output: 5V at 3A" is telling me that. A normal USB charger can't supply 3 Amps of current.

Thanks so much. I am clearly a dunce about electronics!

[j.p.s]

Originally Posted by Catlady

It's Greek to me, plus I haven't done any research beyond checking the other day that ASUS no longer sells the charger separately.

Think of electricity in general, and battery charging in particular, as like filling a water container, but with simpler math because of saner units.

Electric voltage is like water pressure. Too low, doesn't work well. Too high, something breaks.

Electric current is like flow rate. You can't fill a swimming pool through a soda straw or a drinking cup from a fire hose.

Battery capacity is in watt-hours. Watts = Volts times Amperes.

5V * 0.5A = 2.5W

2.5W * 2hours = 5W-hours

(There are complicating factors such as losses, but that isn't needed for a basic understanding of the concepts.)

[Catlady]

Originally Posted by j.p.s

Think of electricity in general, and battery charging in particular, as like filling a water container, but with simpler math because of saner units.

Electric voltage is like water pressure. Too low, doesn't work well. Too high, something breaks.

Electric current is like flow rate. You can't fill a swimming pool through a soda straw or a drinking cup from a fire hose.

Battery capacity is in watt-hours. Watts = Volts times Amperes.

5V * 0.5A = 2.5W

2.5W * 2hours = 5W-hours

(There are complicating factors such as losses, but that isn't needed for a basic understanding of the concepts.)

This is the kind of thing where I understand all the words, and it all seems to make sense as I read it, but my brain doesn't actually comprehend it and turn it into concepts I can apply to what I see in the specs. It's like a foreign language.

[j.p.s]

Originally Posted by Catlady

This is the kind of thing where I understand all the words, and it all seems to make sense as I read it, but my brain doesn't actually comprehend it and turn it into concepts I can apply to what I see in the specs. It's like a foreign language.

OK. For chargers, just ignore everything except 2 things:

1. Voltage must match. (Fortunately, for small devices, everything new is 5 volts, and for
USB, that is sacred.)

2. Charger current capability must be at least what the device needs. The 5 volt part
guarantees that it does not matter how much above the minimum current it has.

So for USB chargers, the voltage is automatically correct and all you need to do is make sure it can supply enough amperes. There is no danger of too many amperes.

[j.p.s]

Originally Posted by Catlady

It's got a micro USB, not a mini (I always confuse those).

The mini USB is the one that's easy to plug in.

The micro USB is the other one.

[Catlady]

Originally Posted by j.p.s

OK. For chargers, just ignore everything except 2 things:

1. Voltage must match. (Fortunately, for small devices, everything new is 5 volts, and for
USB, that is sacred.)

2. Charger current capability must be at least what the device needs. The 5 volt part
guarantees that it does not matter how much above the minimum current it has.

So for USB chargers, the voltage is automatically correct and all you need to do is make sure it can supply enough amperes. There is no danger of too many amperes.

But if there are too few amperes it won't charge? So a 5V phone charger won't charge the ASUS, but I could use the ASUS charger to charge a phone?

[DNSB]

Originally Posted by Catlady

But if there are too few amperes it won't charge? So a 5V phone charger won't charge the ASUS, but I could use the ASUS charger to charge a phone?

Pretty much yes. The phone will limit it's input current to keep from charging the battery too fast. I've charged quite a few devices from a iPad charger which has a maximum output of 2.1A (2100mA) without issue.

[j.p.s]

Originally Posted by Catlady

But if there are too few amperes it won't charge? So a 5V phone charger won't charge the ASUS, but I could use the ASUS charger to charge a phone?

That is more complicated.

It might charge very slowly, which isn't so bad if there is no alternative.

It might do nothing, which doesn't hurt, but doesn't help. (Well, I guess it hurts if it results in a nasty surprise when you go to use.

At the USB standard half ampere, my phone wakes up and slowly drains the battery until it is low enough to cause a forced shutdown.

There are probably other things that can happen, but most people should just make sure the charger has enough amperes.

[Catlady]

OK, thanks, I think I understand--at least enough to know that I should buy a replacement for the ASUS charger!

[JSWolf]

Originally Posted by HarryT

In that case, no, a standard USB charger won't work.

Actually, I think standard are changing and most USB chargers are now able to supply more than 1A. USB chargers that just do 1A are a dying breed.

[rraod]

I am using an Aukey 3 port 2.4A Quick Charge 2.0 charger for all my devices in home. In my car I have an Anker 4 port 2.4A USB charger.

These two chargers are very good and satisfy all my charging needs (period)