12v to 5 v USB charger

[allyncooper]

Got an off brand 9" tablet for semi-permanent installation for nav, etc. Looking for a 12v to 5v USB charger to keep it going. Intend to hardwire the 12v side. Ones I've looked at on Amazon ( $8 to $12 price range) all claim to put out 3amps, although many reviewers who have run tests say this is sometimes overrated (some which claimed 3 amps tested at only half that) . Can anyone recommend a unit that puts out a full 3 amps or at least enough to adequately charge a 9" tablet when in use for navigation and other apps? I did try to find out the power requirements of my tablet but couldn't find it, so info on what a typical tablet that size would need is appreciated. TIA

 

[Gamin]

Check out "Blue Sea Systems" (http://www.amazon.com/dp/B01BV1MTAA/ref=wl_it_dp_o_pd_nS_ttl) They claim to have 4.8A (oops) out put on both ports.

 

[cyclic]

Here's the one I'm using in my truck................................. More current than you need, but definitely worth it as it's also a hub if you want to configure tablets and phones to read usb drives and tv dongles.

http://www.amazon.com/Yeeco-Converter-Regulator-Automatic-Identification/dp/B016RVSLV0?ie=UTF8&refRID=2GCKBXXBWDMFMNS6FK5Y&ref_=pd_ybh_a_26

 

[IdaSHO]

What brand tablet?

My old Ipad Air only was only rated to draw 2.4 amps IIRC

And it would run all day and maintain full charge on these guys...

I have a few of these installed in my custom camper

http://www.ebay.com/itm/2-1A-DUAL-U...ash=item3d02d48ef7:g:u6YAAOSw0e9Urej-&vxp=mtr


Cheap and effective. A few years later and no problems to report.

They power small fans, the wife's little reading light in the cab-over, charges Iphones, tablets, etc.


Only thing i dont like about them is the silly blue indicator light. Had to block that out. SUPER bright at night.

Although, if you feel you need a night, light they would certainly work for that :sombrero:

 

[pugslyyy]

I buy these things off ebay/amazon, take them apart, and use the pieces. I've found it is the cheapest way to get the parts.

http://smile.amazon.com/niceEshop-D...1&redirect=true&ref_=oh_aui_search_detailpage

 

[Kerensky97]

The power output of USB ports is defined by the USB industry designed standard.
500mA was the basic unit or a single port could take all unit loads of the bus and provide upto about 2000mA. That's why most phone (esp iPhone) ports say they're rated for .5amps and tablets (iPad) ports say they're 1.5 or 2amps. It was reported that charging older iPhones on more than the .5amps port would kill or shorten the battery life. But everybody got sick of waiting 5 hours for their phone to charge and all modern phones are usually able to "fast charge" which is just marketing speak for saying they are setup to safely charge at 2amps like tablets. In the last 2 years a new "power charging" option has been added to the USB spec but it's not meant for charging individual phone/tablet devices (20v and 5amps into 5v 2amp device is bad mojo).

TL;DR: Your tablet is likely only designed to pull 2amps anyway, and pumping much more amperage through the USB bus than it's specified for could cause damage. So just get a decent 12v adapter with a port that says it does 2.1amps, or "tablets", or "Android".

Personally I like Anker products. I've used and abused many of their batteries and chargers and they always come through great and kept my devices alive. Their "IQ ports" are basically just auto sensing ports that can switch between the old .5 and newer 2amp outputs. But having 12v adapter that can power 5 individual devices at 2amps each is nice.

Also if you're still discharging your tablet even though it's plugged in at 2amps means you probably need to figure out what's taxing the tablet power so much. I've done it, I killed a Samsung S4 that pulled so much power the battery would heat the phone up until it burnt your finger touching the screen. It's tempting to just pump more charge through it but you'll just end up cooking an expensive to replace device.

 

[allyncooper]

Thanks for all the replies, some good information to guide me. Some of you suggested the in dash mount device, but I already have that. Looking for something to hardwire to do away with the wire clutter since I have the monitor mounted overhead.

Looking at units like this, just want to make sure they have adequate power.

 

[rayra]

at 1.25A for the one pictured (watts divided by volts is Amps), I would say no. And that device has two USB connections. The 1.25A is total for the device, so if you plug two devices in you're going to get only ~half that for each (providing they are both drawing)
Depending on the size of the tablet and its workload and particularly what wireless functions you plan to use. Run the cell wireless, bluetooth for an OBDII dongle for something like Torque AND the GPS for nav functions, I would think you'd need something in at least the 2.1A tier and maybe even more, to sustain a full load.

 

[texascrane]

at 1.25A for the one pictured (watts divided by volts is Amps), I would say no. And that device has two USB connections. The 1.25A is total for the device, so if you plug two devices in you're going to get only ~half that for each (providing they are both drawing)
Depending on the size of the tablet and its workload and particularly what wireless functions you plan to use. Run the cell wireless, bluetooth for an OBDII dongle for something like Torque AND the GPS for nav functions, I would think you'd need something in at least the 2.1A tier and maybe even more, to sustain a full load.

USB is 5 volts, so it's actually putting out 3 amps.