Samsung Galaxy Tab Active Pro SM-T547U In A Ram Mount Tough-Case for Tab Active Pro Charging
 |
    17 years
|
I have a Samsung Galaxy Tab Active Pro SM-T547U tablet in a Ram Mount Tough-Case for Tab Active Pro. It has a power cord with a USB-A connector. My wife and I used it yesterday in our Can Am Maverick running the Polaris Ride Command Android app. In the Maverick 12 volt power outlet I have a Scosche dual USB car charger. The car charger is marked on the side:
Input: 10-16VDC 2.9 A
Output: 2.4A Per USB Port
When we used it yesterday the Samsung tablet showed that it was charging, but the charging never kept up. In other words, even though it showed it was charging, the battery percentage dropped during the ride.
I am now trying to determine what is causing it and how to proceed. It is possible that the Can Am is giving less than 2.9 amps at the power outlet that the Scosche needs. I suppose that can be measured with a multimeter.
The next possibility is that the Scosche dual USB car charger isn't really putting out the 2.4 amps that is claims. Can that also be checked with a multimeter?
I now want to try a different car charger that has at least one USB-A that puts out enough power to charge the Samsung and keep it at 100% battery.
I do recall reading that 18 watts per per is the maximum that a USB-A port can deliver.
I am considering a Ram GDS Type-C and Type A 2-Port Cigarette Charger, Samsung Adaptive Fast Charging Vehicle Charger or an Anker PowerDrive Speed+ 2 Car Charger. From the looks of it, any of them should work equally well. Any other considerations that I should be aware of?
https://www.anker.com/products/a2229?variant=37437958455446#...
https://www.samsung.com/us/mobile/mobile-accessories/phones/...
https://rammount.com/products/ram-gds-charge-pps-cigc
The issue may be the charging unit
I recall that older Samsung devices used a specially wired "charging plug" with a resistor wired between 2 of the USB pins. I cannot remember which pins. The Samsung device was able to determine if the "charging plug" was a high amperage type vs the standard USB trickle charge. I wired up a 12VDC plug to fit the cigarette lighter so that the tablet would think I was using a OEM Samsung wall plug which could supply higher amperage. Also, the value of the resistor was not standard and other manufacturers used different values.
I do not know if this is still the case with new devices, but I would say yes since the device really would not know what type of charging device is being used and default to the standard USB trickle charge amperage.
I would think the Samsung Adaptive Fast Charging Vehicle Charger you listed has such a resistor wired into the plug as well as a charging circuit capable of delivering the required current.
The Samsung problem
I recall that older Samsung devices used a specially wired "charging plug" with a resistor wired between 2 of the USB pins. I cannot remember which pins. The Samsung device was able to determine if the "charging plug" was a high amperage type vs the standard USB trickle charge. I wired up a 12VDC plug to fit the cigarette lighter so that the tablet would think I was using a OEM Samsung wall plug which could supply higher amperage. Also, the value of the resistor was not standard and other manufacturers used different values.
I do not know if this is still the case with new devices, but I would say yes since the device really would not know what type of charging device is being used and default to the standard USB trickle charge amperage.
I would think the Samsung Adaptive Fast Charging Vehicle Charger you listed has such a resistor wired into the plug as well as a charging circuit capable of delivering the required current.
The link at https://www.instructables.com/Garmin-Samsung-Charger-Reverse... describes at least one issue and mod to the Samsung situation. Scroll down to Step 4 The Samsung problem. One issue I see in making mods is just where do you buy resistors in singular quantities? Where is Radio Shack when you need them?
John from PA
Samsung Galaxy Tab Active Pro SM-T547U In A Ram Mount Tough-Case
Thank you very much for the reply.
I see references made to fast charging vs. slow charging on smartphones and tablets.
Is there a recognized standard for what is fast and what is slow?
I seems to recall that USB is 5 volts.
More than just voltage
It goes beyond voltage and includes the parameter of current capability of the charger and what the device might also accept. For a good relatively non-technical explanation and the advantages/disadvantages see the content at https://www.pcmag.com/how-to/what-is-fast-charging.
For discussion of the various standards, there is good content at https://www.digitaltrends.com/mobile/how-does-fast-charging-....
John from PA
Samsung Galaxy Tab Active Pro SM-T547U In A Ram Mount Tough-Case
That is a great reply. Thank you very much.
Modding a cable for Samsung
@JohnFromPA "One issue I see in making mods is just where do you buy resistors in singular quantities
I found that Radio Shack inventory limited. Here in Toronto, we have several stores that sell individual resistors, transitors, caps, breadboards, connectors, etc. I agree, these stores are getting more difficult to find!
Another issue in doing mods: bad soldering results in shorts that can damage things.