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  #1 (permalink)  
Old 05-04-2012, 06:23 PM
Ryan P.
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Default Car Chargers

Finding a car charger that will charge and Android Tablet is proving
to be highly annoying. The vast majority of chargers out there are
built for Apple devices, which have different logic for determining how
much power to draw from the charger.

I have ZTE Optik (actually, we'd like to use these in our fleet)
tablet. ZTE does not offer a vehicle charger, and none of the 2.1a
chargers we've tried will send more than .5a to the tablet... which
means it consistently loses battery throughout the day.

Has anyone run into this problem with this, or any other USB car
charger? Can you recommend one that you've used to charge your device?

Thanks,

Ryan

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  #2 (permalink)  
Old 05-04-2012, 07:41 PM
Paul Miner
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Default Re: Car Chargers

On Fri, 04 May 2012 13:23:25 -0500, "Ryan P."
<rdeleteyannewguy@gremovemail.com> wrote:

> Finding a car charger that will charge and Android Tablet is proving
>to be highly annoying. The vast majority of chargers out there are
>built for Apple devices, which have different logic for determining how
>much power to draw from the charger.
>
> I have ZTE Optik (actually, we'd like to use these in our fleet)
>tablet. ZTE does not offer a vehicle charger, and none of the 2.1a
>chargers we've tried will send more than .5a to the tablet... which
>means it consistently loses battery throughout the day.
>
> Has anyone run into this problem with this, or any other USB car
>charger? Can you recommend one that you've used to charge your device?


Does it have to be USB? Google shows multiple hits for ZTE Optik car
chargers, but they seem to plug into a lighter socket rather than USB.

On a related note, I don't know of any generic USB ports that can
handle a sustained 2.1 amp load. They're usually limited to about .5
amps, as you've seen.

--
Paul Miner

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  #3 (permalink)  
Old 05-04-2012, 07:53 PM
Ryan P.
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Default Re: Car Chargers

On 5/4/2012 2:41 PM, Paul Miner wrote:
> On Fri, 04 May 2012 13:23:25 -0500, "Ryan P."
> <rdeleteyannewguy@gremovemail.com> wrote:
>
>> Finding a car charger that will charge and Android Tablet is proving
>> to be highly annoying. The vast majority of chargers out there are
>> built for Apple devices, which have different logic for determining how
>> much power to draw from the charger.
>>
>> I have ZTE Optik (actually, we'd like to use these in our fleet)
>> tablet. ZTE does not offer a vehicle charger, and none of the 2.1a
>> chargers we've tried will send more than .5a to the tablet... which
>> means it consistently loses battery throughout the day.
>>
>> Has anyone run into this problem with this, or any other USB car
>> charger? Can you recommend one that you've used to charge your device?

>
> Does it have to be USB? Google shows multiple hits for ZTE Optik car
> chargers, but they seem to plug into a lighter socket rather than USB.
>
> On a related note, I don't know of any generic USB ports that can
> handle a sustained 2.1 amp load. They're usually limited to about .5
> amps, as you've seen.
>


Sorry, I could have been a little clearer. There are no (that
I've found) dedicated ZTE Optik (tablet version) car chargers. The only
official option is to use an inverter and plug the AC adapter into that
(which is what our Sprint said ZTE suggested). This is impractical for
a fleet to use, because it is bulky and creates two potential points of
failure.

Most of the ZTE Optik results in Google point to chargers for the
phone version, not the tablet version. The tablet has a 40-pin
connector at the other end of the USB cable.

Since I know iPads and can be charged using certain 12v USB car
chargers, I know its possible for a tablet with a 2.1a power requirement
to be charged in a car... Its just a matter of either finding a way to
fool the logic in the Android tablet, or finding a car charger made for
the Optik tablet.

I've read that shorting the two data terminals on the USB port will
fool Android devices in drawing more than .5a... I'm tempted to try that.

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  #4 (permalink)  
Old 05-06-2012, 08:02 AM
Bobby
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Posts: n/a
Default Re: Car Chargers

Try Here Hope You Find What Your Looking For
http://www.tmiwireless.com/accessories/?aid=6808


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  #5 (permalink)  
Old 05-06-2012, 06:12 PM
SMS
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Posts: n/a
Default Re: Car Chargers

On 5/4/2012 12:53 PM, Ryan P. wrote:
> On 5/4/2012 2:41 PM, Paul Miner wrote:
>> On Fri, 04 May 2012 13:23:25 -0500, "Ryan P."
>> <rdeleteyannewguy@gremovemail.com> wrote:
>>
>>> Finding a car charger that will charge and Android Tablet is proving
>>> to be highly annoying. The vast majority of chargers out there are
>>> built for Apple devices, which have different logic for determining how
>>> much power to draw from the charger.
>>>
>>> I have ZTE Optik (actually, we'd like to use these in our fleet)
>>> tablet. ZTE does not offer a vehicle charger, and none of the 2.1a
>>> chargers we've tried will send more than .5a to the tablet... which
>>> means it consistently loses battery throughout the day.
>>>
>>> Has anyone run into this problem with this, or any other USB car
>>> charger? Can you recommend one that you've used to charge your device?

>>
>> Does it have to be USB? Google shows multiple hits for ZTE Optik car
>> chargers, but they seem to plug into a lighter socket rather than USB.
>>
>> On a related note, I don't know of any generic USB ports that can
>> handle a sustained 2.1 amp load. They're usually limited to about .5
>> amps, as you've seen.
>>

>
> Sorry, I could have been a little clearer.


You can still be clearer.

Does the AC charger use a USB socket and a cord with the 40 pin
connector, or is the cord wired directly into the AC charger?

If it's the former, there might be some hope in diddling with data+ and
data-. If it's the latter, forget it.

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  #6 (permalink)  
Old 05-06-2012, 06:12 PM
SMS
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Posts: n/a
Default Re: Car Chargers

On 5/4/2012 11:23 AM, Ryan P. wrote:
> Finding a car charger that will charge and Android Tablet is proving to
> be highly annoying. The vast majority of chargers out there are built
> for Apple devices, which have different logic for determining how much
> power to draw from the charger.
>
> I have ZTE Optik (actually, we'd like to use these in our fleet) tablet.
> ZTE does not offer a vehicle charger, and none of the 2.1a chargers
> we've tried will send more than .5a to the tablet... which means it
> consistently loses battery throughout the day.
>
> Has anyone run into this problem with this, or any other USB car
> charger? Can you recommend one that you've used to charge your device?


I assume that the travel adapter charging via the Micro-USB port, not
the 40 pin port? If so, forget it, other people with ZTE tablets have
reported the same issue.

Using one of the 2.1A USB port/car chargers is not going to help you.
ZTE will not draw more than 0.5A on the Micro-USB port no matter what
you do. Many others have run into this problem.

The logic for determining the available power is not in the high-power
USB port, it's in the cable that came with the tablet, or in the tablet
itself. Motorola has done this sort of thing for years, and hence a
plain USB to Mini-USB cable not designed for Motorola will give an
"Unauthorized Charger" message (except when it's plugged into a USB port
on a computer with Motorola Phone tools installed).

ZTE has recently released a slew of tablets with that 40 pin connector,
so there should be an after-market solution soon.



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  #7 (permalink)  
Old 05-06-2012, 11:54 PM
Mike S.
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Posts: n/a
Default Re: Car Chargers


In article <4fa6bf26$0$16201$742ec2ed@news.sonic.net>,
SMS <scharf.steven@geemail.com> wrote:
>On 5/4/2012 11:23 AM, Ryan P. wrote:
>> Finding a car charger that will charge and Android Tablet is proving to
>> be highly annoying. The vast majority of chargers out there are built
>> for Apple devices, which have different logic for determining how much
>> power to draw from the charger.
>>
>> I have ZTE Optik (actually, we'd like to use these in our fleet) tablet.
>> ZTE does not offer a vehicle charger, and none of the 2.1a chargers
>> we've tried will send more than .5a to the tablet... which means it
>> consistently loses battery throughout the day.
>>
>> Has anyone run into this problem with this, or any other USB car
>> charger? Can you recommend one that you've used to charge your device?

>
>I assume that the travel adapter charging via the Micro-USB port, not
>the 40 pin port? If so, forget it, other people with ZTE tablets have
>reported the same issue.
>
>Using one of the 2.1A USB port/car chargers is not going to help you.
>ZTE will not draw more than 0.5A on the Micro-USB port no matter what
>you do. Many others have run into this problem.
>
>The logic for determining the available power is not in the high-power
>USB port, it's in the cable that came with the tablet, or in the tablet
>itself. Motorola has done this sort of thing for years, and hence a
>plain USB to Mini-USB cable not designed for Motorola will give an
>"Unauthorized Charger" message (except when it's plugged into a USB port
>on a computer with Motorola Phone tools installed).
>
>ZTE has recently released a slew of tablets with that 40 pin connector,
>so there should be an after-market solution soon.


eBay is full of dongles that perform the proper jumpering to charge
Samsung tablets using generic high-current USB adaptors. Ditto for iPad.
Perhaps one of these will work; or maybe there already is such a dongle
for the OP's brand.


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  #8 (permalink)  
Old 05-07-2012, 03:16 PM
SMS
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Posts: n/a
Default Re: Car Chargers

On 5/6/2012 4:54 PM, Mike S. wrote:

> eBay is full of dongles that perform the proper jumpering to charge
> Samsung tablets using generic high-current USB adaptors. Ditto for iPad.
> Perhaps one of these will work; or maybe there already is such a dongle
> for the OP's brand.


Perhaps. Too little information was given. The ZTE tablets with that 40
pin connector are just hitting the market so we'll soon see.

I assume that ZTE provides a USB to 40 pin cable that is used for two
things:

1) To connect the tablet to a computer, where you don't want to draw
much more than 500mA (most computers won't trip the USB over-current
protection until 800-1000mA even though they don't have to supply more
than 500mA).

2) To connect the tablet to the AC charger.

So for the tablet to draw more than 500mA from the AC charger, there
must be something on the USB data pins that the tablet looks at. Since
they're unlikely to have put a micro-controller in the AC charger that
generates any data (even Apple doesn't do this), I would suspect that
it's a voltage on one or both of the data pins created by a voltage
divider for each pin, or both data pins shorted together and one voltage
divider network for both pins.

Looking at the pins with a VOM could determine what's going on.

What Other Tablet Makers Do
---------------------------
Samsung shorts the data pins together and uses a voltage divider to put
1V on the both data pins.

Apple has multiple charge rates based on the voltage on each data pin.
Data+ and Data- can be either +2.0 or +2.8, giving four possible charge
rates.

500mA (probably iPod)
D- 2.0V
D+ 2.0V

1000mA (probably iPhone, iPod Touch)
D- 2.8V
D+ 2.0V

2000mA (iPad)
D- 2.0V
D+ 2.8V

Not Used
D- 2.8V
D+ 2.8V

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  #9 (permalink)  
Old 05-09-2012, 01:34 PM
Ryan P.
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Posts: n/a
Default Re: Car Chargers

On 5/6/2012 1:12 PM, SMS wrote:
> On 5/4/2012 12:53 PM, Ryan P. wrote:


>> Sorry, I could have been a little clearer.

>
> You can still be clearer.
>
> Does the AC charger use a USB socket and a cord with the 40 pin
> connector, or is the cord wired directly into the AC charger?
>
> If it's the former, there might be some hope in diddling with data+ and
> data-. If it's the latter, forget it.


Its USB on one end, 40 pin on the other.

I indeed shorted the two data pins, and that allowed the tablet to
draw the 2.1a that it required.

I was hoping I wouldn't have to modify 50 car chargers, but it looks
like that's what I'm going to have to do.

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  #10 (permalink)  
Old 05-09-2012, 01:54 PM
Ryan P.
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Posts: n/a
Default Re: Car Chargers

On 5/6/2012 6:54 PM, Mike S. wrote:
> In article<4fa6bf26$0$16201$742ec2ed@news.sonic.net>,
> SMS<scharf.steven@geemail.com> wrote:
>> On 5/4/2012 11:23 AM, Ryan P. wrote:
>>> Finding a car charger that will charge and Android Tablet is proving to
>>> be highly annoying. The vast majority of chargers out there are built
>>> for Apple devices, which have different logic for determining how much
>>> power to draw from the charger.
>>>
>>> I have ZTE Optik (actually, we'd like to use these in our fleet) tablet.
>>> ZTE does not offer a vehicle charger, and none of the 2.1a chargers
>>> we've tried will send more than .5a to the tablet... which means it
>>> consistently loses battery throughout the day.
>>>
>>> Has anyone run into this problem with this, or any other USB car
>>> charger? Can you recommend one that you've used to charge your device?

>>
>> I assume that the travel adapter charging via the Micro-USB port, not
>> the 40 pin port? If so, forget it, other people with ZTE tablets have
>> reported the same issue.
>>
>> Using one of the 2.1A USB port/car chargers is not going to help you.
>> ZTE will not draw more than 0.5A on the Micro-USB port no matter what
>> you do. Many others have run into this problem.
>>
>> The logic for determining the available power is not in the high-power
>> USB port, it's in the cable that came with the tablet, or in the tablet
>> itself. Motorola has done this sort of thing for years, and hence a
>> plain USB to Mini-USB cable not designed for Motorola will give an
>> "Unauthorized Charger" message (except when it's plugged into a USB port
>> on a computer with Motorola Phone tools installed).
>>
>> ZTE has recently released a slew of tablets with that 40 pin connector,
>> so there should be an after-market solution soon.

>
> eBay is full of dongles that perform the proper jumpering to charge
> Samsung tablets using generic high-current USB adaptors. Ditto for iPad.
> Perhaps one of these will work; or maybe there already is such a dongle
> for the OP's brand.


I did see some chargers listed as being compatible with the
Transformer, but all the details I saw on them implied that provide TOO
much power, and I'm not sure how much I trust such a cheap tablet to be
be able to regulate an over-abundance of power.

Other 40 pin "charger cables" I've found online didn't provide enough
information in the description for me to know if it was a modified cable
or just a spare "normal" cable.

So far, it looks like I will have to manually short the data pins on
the chargers. I tried this over the weekend, and haven't seen any nasty
side effects on either the tablet or the vehicle I left it charging in.

According to our Sprint rep, ZTE does not offer a DC charger. In
fact, ZTE's response to their inquiry was to tell me to use an inverter,
which over a fleet of 50 vehicles is a bit impractical.

Thank you all for the information on chargers, though. I knew that
there were differences in how the devices decided how much power to
draw, but I received a good education here.

Ryan

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  #11 (permalink)  
Old 05-09-2012, 05:53 PM
SMS
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Posts: n/a
Default Re: Car Chargers

On 5/9/2012 6:54 AM, Ryan P. wrote:

> So far, it looks like I will have to manually short the data pins on the
> chargers. I tried this over the weekend, and haven't seen any nasty side
> effects on either the tablet or the vehicle I left it charging in.


I think what I would do would to be to buy 50 of these:
<http://www.monoprice.com/products/product.asp?seq=1&p_id=6504>, cut
them in half, short the data pins, solder them back together and use
heat shrink tubing over the cable. Depending on where you are, you could
probably find someone to do the work for you for a few dollars per cable.

By doing the cable, you can use any high-current 12V to USB adapter.

Also, chargers tend to be something that break a lot, and you'd probably
void the Sprint/ZTE warranty buy opening it and shorting the data pins.

Oh, and maybe make up some extras to sell on eBay!

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  #12 (permalink)  
Old 05-09-2012, 07:03 PM
Paul Miner
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Posts: n/a
Default Re: Car Chargers

On Wed, 09 May 2012 10:53:29 -0700, SMS <scharf.steven@geemail.com>
wrote:

>On 5/9/2012 6:54 AM, Ryan P. wrote:
>
>> So far, it looks like I will have to manually short the data pins on the
>> chargers. I tried this over the weekend, and haven't seen any nasty side
>> effects on either the tablet or the vehicle I left it charging in.

>
>I think what I would do would to be to buy 50 of these:
><http://www.monoprice.com/products/product.asp?seq=1&p_id=6504>, cut
>them in half, short the data pins, solder them back together and use
>heat shrink tubing over the cable. Depending on where you are, you could
>probably find someone to do the work for you for a few dollars per cable.
>
>By doing the cable, you can use any high-current 12V to USB adapter.
>
>Also, chargers tend to be something that break a lot, and you'd probably
>void the Sprint/ZTE warranty buy opening it and shorting the data pins.
>
>Oh, and maybe make up some extras to sell on eBay!


I had the same idea and think it's the best way to go. No damage to
the chargers and it's all plug and play.

--
Paul Miner

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  #13 (permalink)  
Old 11-15-2012, 11:09 PM
Junior Member
 
Join Date: Nov 2012
Posts: 2
Default Zte

Hi
I happend to stumble on you conversation about car chargers etc,maybe you can help me.I have a vodafone smart tab 10 also known as the zte v11a I think.I have given the last three weeks trying to locate a 40 pin to USB data / charger cable as I lost mine .I have gone back to vodafone , zte direct and to no avail.would you be able to guide me in the right direction to finding one .I know you were talking about the optik in your conversation but maybe they are the same lead
Thanks
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  #14 (permalink)  
Old 11-16-2012, 07:28 AM
Junior Member
 
Join Date: Nov 2012
Posts: 2
Default

Hi,
Would anyone here be able to suggest where I can get my hands on a 40 pin to USB data/charger lead for zte tablet .
Thanks
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