smartphones and electricity question

[Sideoftheroad]

With a good amount of folks with electrician or electrical backgrounds thought I would post this and see what you guys think.

 

1st I will say the response I was given I think is a bunch of b.s. and just a gimmick to get you to buy a new charger unneccesarily. I currently have an LG ENV3 and I was looking at the LG Revolution. I asked the rep about the car charger I have will work with this smartphone. She removed the cover and the ports were the same so in my mind it should work. She said no as the car charger I have doesn't produce enough juice to charge the battery. She made some comment about it might even cause premature battery wear. Every single smart phone review that I have read no matter which one it is, all say smartphone battery life is bad, so again don't really see how I am at a disadvantage here.

 

So I also posted this question on the verizon wireless facebook page and here is one response I got "Because the charger isn't strong enough to charge a smartphone. All chargers go up to a certain wattage, and a smartphone takes a higher wattage."

 

So to my question is what is your take on the wattage comment?

[Monty]

It's all bogus. It'll work just fine.

 

 

 

[Sideoftheroad]

The girl said something about they just had like an hour long training on it, but I don't think she understood it. I am sure I wouldn't either. I could probably get the basics of what they were saying if I heard it, but unless someone like yourself hears/sees the method behind the madness to understand the actual science behind the reason why, I say it is bogus too. I am not putting down the sales reps, but I would guestimate nationwide 99% of the reps don't have any type of electrical background and don't understand it so they just repeat what they were told. It came from corp. so it must be true.

 

If more respond, put your background like Monty did.

[dingy]

The possible lower wattage will translate into a longer time needed to charge the phone, but if the output voltage is the same it will never the less still charge it.

 

The possible glitch is if your smartphone consumes a higher amount of wattage when it is operating than the charger will put out, then there will still be a drain on the battery. Doubtful, but worth mentioning.

 

(Aspiring Mad Scientist)

 

Gary

[Sideoftheroad]

But if (I know big if being a car charger) the phone is turned off then that shouldn't be an issue, would you agree?

[bkuhr]

Maybe.

 

env3=900mA battery

revolution=1500mA battery

both use micro usb which = 5vdc

car chargers typically use voltage converter to step down 12-14v to steady 5vdc, and may include overcurrent protection circuit (typically fuse), but not typically current control.

 

I believe it would work just fine, just take longer to restore full charge, but would likely be same longer time with other charger.

 

past aircraft and component repair electrician

Edited September 2, 2011 by bkuhr
missed requirement to post title

[BradT]

Dingy I agree with you, and is it lower wattage is also lower amperage so it could easily drain the battery, most likely while talking.

 

I think her comments are also correct, but should still work just may have to replace the battery sooner

 

Brad

[Monty]

I have a Droid Incredible smart phone, and I use the car charger every day. It seems like it charges just as fast as the house charger.

[flb_78]

So get a little 75watt 120volt inverter that plugs into your cig lighter socket and use a regular wall charger.

 

http://www.radioshack.com/product/index.jsp?productId=3875385&CAWELAID=422931494

[StormRaven]

Wattage Smattage, when it comes to charging a device it's all about the volts. Too little and you're potentially weakening the battery (really bad on Ni-CADs, not so bad on the Lithium IONS found in cell phones). Too much and you're creating an explosive device.

 

Mini-USB is regulated to a max of 5volts output. No matter how you slice it, the phone is not powered through that port, it only recharges its battery through that port, or charges the battery and allows for data pass through if it's connected to the computer.

 

You really don't have to worry about wattage (voltage x amperage) unless you're actually powering an electronic device. Then you want to make sure that your power supply is putting out the exact voltage and at least as much amps or more than what the device is rated for.

 

And for the record, I don't stay in Holiday Inns, but I am a RadioShack Sales Associate. We get "trained" on this stuff pretty regular. (More like brainwashed if ya ask me, especially in regards to wireless.)

[bkuhr]

Wattage Smattage, when it comes to charging a device it's all about the volts. Too little and you're potentially weakening the battery (really bad on Ni-CADs, not so bad on the Lithium IONS found in cell phones). Too much and you're creating an explosive device.

 

Mini-USB is regulated to a max of 5volts output. No matter how you slice it, the phone is not powered through that port, it only recharges its battery through that port, or charges the battery and allows for data pass through if it's connected to the computer.

 

You really don't have to worry about wattage (voltage x amperage) unless you're actually powering an electronic device. Then you want to make sure that your power supply is putting out the exact voltage and at least as much amps or more than what the device is rated for.

 

And for the record, I don't stay in Holiday Inns, but I am a RadioShack Sales Associate. We get "trained" on this stuff pretty regular. (More like brainwashed if ya ask me, especially in regards to wireless.)

 

For most part I agree, but a device that requires more amps than the charger can deliver will cause, at best case a drop of the 5volt level. Most smart devices will detect this improper charging voltage, and seperate themselves from the source. Dumb devices will continue to use this lower voltage, at risk of damage to the device or charger.

 

attached intersting read for electrophobes

 

http://pinouts.ru/Slots/USB_pinout.shtml

http://www.girr.org/mac_stuff/usb_stuff.html

Edited September 2, 2011 by bkuhr
another link

[XV1100SE]

Its the amperage you have to look at. USB is a standard but different usb chargers are rated at different amperage

For example...I have an older Blackberry charger that has a usb connector on it and the OUTPUT amps is 700miliamps (.7 amps) and it wont charge my iPod but a newer 750miliamp charger will. The charger for a PlayBook is 1.8amps. Voltage is all the same but it is the amperage that is the key. Newer batterys require higher voltage.

I can use the PlayBook charger on the Blackberry and it charges faster because of the amperage. I would not leave it on the charger for a long period of time. I think it will damage the battery over time. I cannot use the 750mamp charger to charge the PlayBook.

Long story short...the salesperson was correct that you will need a new car charger.

[XV1100SE]

Wattage is a calculation of voltage and amperage...if I remember from high school electrical shop.

[dingy]

But if (I know big if being a car charger) the phone is turned off then that shouldn't be an issue, would you agree?

 

If the phone is powered down, any charger should be able to bring the battery back up. This is based upon the output VOLTAGE of the charger in question being equal to the recommended charger. As I mentioned earlier, it may take a little longer to do, but I don't see any harm in 'trickle' charging a phone.

 

(Wannabee Super Lotto Winner)

 

Gary

[Guest tx2sturgis]

For a whopping $15 for gosh-sakes...buy the new charger!

 

 

Ok...for the record, she may be right. Technically.

 

If the new smartphone has a higher capacity battery, and it seems that it does, then it may take the old charger longer...maybe twice as long, to charge the new phone's battery. Its possible that the old charger may not be able to simultaneously charge and power the new phone during a phone call or data use. Most of these little chargers have some level of regulation built-in*, and wont supply too much current to the intended device, or they wont get 'approved' for use with that phone.

 

In some cases the new smartphones 'detect' the old charger and as stated earlier, they will 'disconnect' or they put up a warning. such as 'not charging'.

 

For example, the Apple iPad, which has a large battery, will not charge properly when connected to an iPhone charger (even though the connectors are the same) IF the ipad is operating.

 

If the iPad is put into 'sleep' mode, it WILL begin to charge, but very slowly. If you 'wake' the iPad, it will tell you with an icon and warning that it is NOT charging. Now if you take that same iPad charger, and you plug the iPad charger into an iPhone, THAT will work just fine. The iPad chargers are rated at 2 amps, or sometimes the package says 10 Watts. (5v x 2 amps)

 

So, it could be that the sales people are told all this to prevent the customer from having issues. If you go outside her advice, it may work, or it may not.

 

Again...you can buy a car charger for around $15 in most electronics stores...so why lose sleep over this one?

 

 

 

 

(*Footnote: Many of these chargers are designed to 'pulse' the charge current intermittently as the phone begins to reach maximum charge, and this way the phone can monitor the state of charge of its battery, between bursts, (and sometimes by calculating charge times using a charge algorithm) and report back with a signal to the charger that it is nearly charged, and can switch to 'trickle mode'. The phone really has no way of regulating the charge other than being used with an 'approved' charger. These high capacity lithium polymer batteries and other chemistries can become overheated and catch fire if not charged correctly...its not a car battery we are talking about...you dont want a phone to catch fire in your pocket or on your nitestand.)

 

 

 

 

 

Edited September 2, 2011 by tx2sturgis

[BuddyRich]

Uh, All to complicated guys. Your not trying to match an Op amp to an RF application . Plug it in and let it run for an hour. If its charging keep it. If not buy the new one.

[LilBeaver]

...

"Because the charger isn't strong enough to charge a smartphone. All chargers go up to a certain wattage, and a smartphone takes a higher wattage."

 

So to my question is what is your take on the wattage comment?

 

To focus on your question:

 

Comments like this can be misleading but so are comments that say you can completely ignore a current or voltage rating. The fact of the matter is one really ought to stay tuned to ALL of the ratings. Some applications are much more sensitive than others.

 

From a pure fundamental electrical standpoint, matching the voltage and current rating listed on the device with what the charger states is optimal, and yes, somewhere on each you'll see something that give some indication of what the ratings are on both the phone AND the charger. HOWEVER, from a practical standpoint, as TX2Sturgis pointed out (), there may be a bit more to the actual charger than the pure electrical ratings; be it an integrated logic circuit, the s.m.a.r.t. monitoring technology, or what have you.

I will spare the lecture unless someone really wants to hear a more complete explanation.

 

Since everyone else is offering their opinions here...

In my opinion, your best bet would be to READ the manual or the charger package and see if LG lists both phones on the charger package as being compatible. If so, then your old one is fine. If not then spend the 15-20 bucks on the recommended (and brand name) new charger to keep from voiding the warranty on your brand new $600 phone.

 

 

...

 

If more respond, put your background like Monty did.

 

I did not stay at a Holiday Inn Express last night nor did I receive any special 'training' to sell phones or whatever so maybe I am really not as qualified to respond as others here may be...

 

I do, however, have a Masters degree in Physics and am nearly finished with my P.hD [in Physics].

Some of the classes that I have taught include [college level] electricity and magnetism courses.

My current research is in solid state/condensed matter/semiconductor physics.