USB charger

schm1dt said:

I tried to charge my A700 with a HTC USB charger, but it didn't work. Can anybody confirm that the A700 only can be charged with the original Charger and not with any micro USB cable?

Sent from my HTC HD2 using XDA

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I tried several ones and none worked.

But this was well known befor the device was available. This is necessary because of the huge power pack.

The original charger can provide 12V and 1,5 A. The USB specification is only 5V and 500 mA.

Did you try to charge the HTC with the acer charger ? you cannont plug it ! they added a pin

Out of couriosity,
in this preview they tell us it would charge on USB???
http://youtu.be/Zy736u97xJA

Not good News at all, im lucky i did not preordered this device, its a no go for me...
Can anyone try to charge over USB while the device is turned off, maybe this works?

Greetz Tokl

Tokl said:

Can anyone try to charge over USB while the device is turned off, maybe this works?l

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No, it doesn't take any power from regular USB pins.

One has the choice: big power pack or loading by USB. I prefer the running time of this device.

Edit: Loading via USB would take over 24 houres for sure.

schm1dt said:

Did someone already find a car charger

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Not yet, I think third party suppliers just need a bit more time.

I have a different experience to your's.

I've tested USB charging with two different USB-chargers. One from Nokia (5V, 1200mA) and one from Samsung (genuine SGS2 charger). Both charge the A700 in stand by mode with about 4% per hour and up to 100% battery capacity. The android battery info does not say "charging" but it does!

When the A700 is switched on my 5V chargers are to weak to charge it.

Shudushi said:

I have a different experience to your's.

I've tested USB charging with two different USB-chargers. One from Nokia (5V, 1200mA) and one from Samsung (genuine SGS2 charger). Both charge the A700 in stand by mode with about 4% per hour and up to 100% battery capacity. The android battery info does not say "charging" but it does!

When the A700 is switched on my 5V chargers are to weak to charge it.

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Nice info, but i guess the charging led is off too ?

schm1dt said:

Confirmed

I charged my A700 with my HTC USB charger (HTC TC E250) in standby mode this night. It charged from 23% to 64% in about 10 hours. There was nothing at the A700 that showed it is charging.
To be honest, 4% per hour is "nearly not charging".

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This is known as trickle charge. The device might charge if the micro USB provides enought mili amps AND the device does not need much power when connected (i.e. screen off).
I really doubt that the device will charge on USB when the screen is on, but on the other hand the device will definitly discharge slower when connected to USB.

I have a small calculation to explain things:
The original charger operates with 12V at 1.5 Amps = 18 Watts (which is not USB compatible so they hat to change the jack to ensure it will not be pluged in to a normal USB device and damage it)
If you would like to have the same Power over USB with its 5V max voltage you would need at least 3,6 Amps. Now that is far to much for those little pins on the micro USB jack and the currency would damage the pins when pluggin in and out.
USB standard specification normally is 500mA = 0,5 Amps ( -> 2,5 Watts in comparison with 3,6 Amps 18Watts)
So I think Acer has done a quite nice compromise.

Hope that clarifies matters a bit.

ninjaw said:

Nice info, but i guess the charging led is off too ?

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Confirmed, no charging LED with standard 5V charger. Orange LED while charging only with original 12V charger.

mearoth said:

This is known as trickle charge. The device might charge if the micro USB provides enought mili amps AND the device does not need much power when connected (i.e. screen off).
I really doubt that the device will charge on USB when the screen is on, but on the other hand the device will definitly discharge slower when connected to USB.

I have a small calculation to explain things:
The original charger operates with 12V at 1.5 Amps = 18 Watts (which is not USB compatible so they hat to change the jack to ensure it will not be pluged in to a normal USB device and damage it)
If you would like to have the same Power over USB with its 5V max voltage you would need at least 3,6 Amps. Now that is far to much for those little pins on the micro USB jack and the currency would damage the pins when pluggin in and out.
USB standard specification normally is 500mA = 0,5 Amps ( -> 2,5 Watts in comparison with 3,6 Amps 18Watts)
So I think Acer has done a quite nice compromise.

Hope that clarifies matters a bit.

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Thanks M8,
this cleares things.

Still waiting for the 3G/4G Device here in Germany

Greetz Tokl

On the A510, when charging the battery via USB, the icon does not indicate it.
That must be the same on the A700.

DЯΦiDi@П said:

But this was well known befor the device was available. This is necessary because of the huge power pack.

The original charger can provide 12V and 1,5 A. The USB specification is only 5V and 500 mA.

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Since USB 2.0 version :
"Several changes and increasing limits including allowing 1.5A on charging ports for unconfigured devices, allowing High Speed communication while having a current up to 1.5A and allowing a maximum current of 5A"

Source : wikipedia.org

Fortunately we are not limited to 500mAh, otherwise we could not quickly recharge our current smartphones .

There are some USB/AC adapters available that put out 2A of juice instead of the typical 1A. For those in the US, check out www.monoprice.com -> they're my go-to source for inexpensive spare cables & such.

It seems that finding a cheaper charger for the A700 isn't a simple task. I had to wade through a lot of cross references with some unintentioned misinformation. First thing was the model number. It's the A510 that is most like the A700 not the A500. Though the A500 does share some similarities it's not the closest match.

When I look for any type of charger, I make sure that the output voltage is correct and the amperage requirements are correct. Looking at the A700's charger, the manufacturer managed to squeeze a lot of info onto it. Amperage is what I always try to find. That is the total amount of current it can handle and deliver to the device connected to it. The A700's charger can handle 1.5 amps. So, the A700 sucks up a quantity of 1.5 amperes of electrons in order for the battery to fill up to it's capacity. That is the load the tablet's battery presents to the charger. Make sure that the charger bought for the A700/A510 can handle at least 1.5 amperes or the wall wart will be OVERLOADED. This is where the charger begins to overheat, smoking warning signals may start coming from the plug and your're asked for a donation for the local voluteer fire department. Besides the voltage which is 12 volts dc, load current requirement is the most important value I make sure is correct for saftey's sake. It is alright to get a charger that has a higher amperage rating but the voltage must be the same, 12vdc for the A700. It just means the charger can handle a larger load.

The only adapter I could find was the original Acer product, mainly because of the unique USB dual purpose connector interface. There is a little diagram of the pinout for the plug on the charger. Using a magnifing glass, I could barely make out the pins the +/-12vdc are attached. Pin P1 is +12vdc and pin P12 is -12vdc. It looks almost beyond a humans capabilities to make or solder together a short plug interface conversion cable in order to use other 12vdc/1.5 A chargers.

I've read in the forums some uncertainty about the proper specs for a replacement charger for the A700, that's why I wrote this post. Maybe , this will help clearup some of the confusion and not add to it. I've also noted a lot of chatter about using a USB cable with the micro USB plug to charge the A700 tablet. Apparently, USB charging can be acheived but it is very slow ( 24 hours or more ) and the amber/white power LED does not indicate the tablet is charging or has finished charging.

If anyone has more info about the A700 charger please reply or post....

Thanks All...

Hi All!

I know that it could be difficult for you to check this Polish site but you can find there a charger that I am going to buy. It has some changeble plugs - also micro usb.
link:
tridex.pl/ramka4.php?menu=towar1&symbol=9396

I think all what you have to do is to look for this kind of a charger - MW3R15GS, btw you can see this name on the original one...

Best regards
Gregork

Acer A701

Save your money and your A701. This thing has only a standard micro-usb plug-in. Check the connector of your Acer charger ... look really close and for better comparison hold a micro-usb-connector from a standard cable next to it. The connector from Acer is longer .. why? because the first row of pins that you can see are not the same ones that fit in a micro-usb-jack. Look deeper into the connector from Acer and you will see a second row of pins.
So if you use this charger with the adapter from that site and set a higer voltage you might fry the usb from your tablet. Sorry to disapoint you but better now than later with a broken tablet.