Based on the same device and 2 AA size rechargeable batteries from this question - Rechargeable battery calculation
Now, the device is used to charge a small 5 inch tablet that have a 3600 mAH battery.
By theory, the device using 2 AA size rechargeable batteries will have a total of 2 x 1900 = 3800 mAH.
Compare to the tablet battery which is 3600 mAH, it should be able to fully charge the whole tablet.
However, when the device with the 2 AA size rechargeable insert and use to charge the tablet, it only manage to charge a max of 20% before the device start blinking and could not charge anymore.
So, the 2 AA size rechargeable batteries of 3800 mAH is only able to charge the tablet for a value of (20% x 3600 mAH = 720 mAH)
So, there is a huge difference of 3800 mAH (the 2 AA size rechargeable battery) minus 720 mAH (the amount it can charge the tablet) equal to 3080 mAH.
So, does it mean that the 2 AA size rechargeable battery of 3800 mAH have only 720 / 3800 = 0.19 (or 19% efficiency to charge a item)?
But the theory say that the 3800 mAH (2 AA size rechargeable batteries) should be able to handle the 3600 mAH tablet battery.
A side note - the 2 AA size rechargeable batteries took 1 hour to charge the the tablet and it only can charge up to 20% of the tablet battery (which is topping up 720 mAH to the tablet battery)
Is there a problem with the circuit or the theory is wrong?