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Tablet charger can't keep up - wire in perm't power

simt

Apr 25, 2017
2
Joined
Apr 25, 2017
Messages
2
Hi,
my car tablet isn't charging fast enough. I need to find a solution and so far I'm thinking about adding in a power supply directly between the battery and the tablet?

The tablet is plugged in via the microUSB charging port to a 5V 2.1A power supply that comes on with the ignition. When I'm driving, the navigation puts a heavy power drain on the tablet. And despite being on the charger the battery will slowly but surely drain to zero and then the tablet shuts down. :( The tablet is installed into the car and not something I want to pull out regularly to charge overnight.

I've thought of a few things to try. I could try a stronger 5v 3A supply through the microUSB charger, but I don't know enough about how the charging circuit works in an Android tablet? On the tablet between the charging port and the battery is there circuitry that will limit the amps into the battery to 5V 2.1A (or 3.7V 1.5A) anyway?

So I've thought about getting a power supply
This one in particular: http://www.ebay.com.au/itm/251768965445?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
and putting it in right between the battery and the terminals into the tablet. I figure it can both charge the battery and power the tablet at the same time. I'd like to keep the battery so the tablet stays alive when car is off. My 'guess' is that I would need to put 3.7V at that point with an oversupply of amps (3-4A) to deal with large instantaneous loads. Ideally the batteries own protection circuit will stop it from overcharging from this supply. - Though once again I'm trying to find out more about how the charging circuit works. Is it the tablet or the battery that stops the battery from charging once it's full?

Ideas?

-Simt
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
Have you checked the existing charger is actually delivering what you expect.?
I saw it reported here not so long ago that some of these units are over-rated.
 

simt

Apr 25, 2017
2
Joined
Apr 25, 2017
Messages
2
Yeah, I've thought about that. As an interim solution, I've ordered an external battery pack. When it arrives (hopefully in the next day or two) I'll be getting in behind the dash to re-arrange things and can also test the power delivery.
 
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