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Hello there at Electrical Engineering SE,

i am thinking about soldering a selfmade micro usb converter for my Acer Switch 10 tablet. After looking at the charger, i found out that it only needs 12 volt and 1,5 amps to charge (considering the tablet can be run while charging, the power requirements are very low). My goal is to make an adapter, so i can charge my tablet on any USB port or with my mobile battery.

In a RasPi project, i already converted 5 volt to 12 volt to power up and run a display. So boosting the voltage is no problem for me.

What i want to know is : considering i can already boost the voltage, do i have to boost the current to 1,5 amps or can i charge my tablet at a lower current without damaging the battery ?

Another question is : Do i have to take other security mechanisms for not to break the internal battery (Like capping the maximum input current to 1,5 amps) ?

Thank you in advance dor helping me making my tab more mobile.

AlphaNERD
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    12V 1.5A is 18 Watts. The typical high current usb charger is 5V 2.1A, which is 10.5 Watts. You won't be able to match it, even before taking efficiency losses into account. Even if you provide a lower current, the tablet will probably discharge faster than it charges. – Passerby Feb 24 '15 at 00:54

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12 volt and 1,5 amps to charge [...] any USB port

12 Volt and 1.5 A means 18 W. To get 18 W from the 5 Volts of the USB port you need at least 3.6 A current - but normal USB will deliver only 0.5A or 1.5 to 2.1A on a specialized charging port. That is simply not enough power.

Turbo J
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