Hi All!
I hope everyone is well & enjoying today!
I bought a 'charger' for my cell phone. It is 120 vac input & DC 5v out in the form of a USB connector. I plug in the included USB to Micro USB cable to charge the phone. About an hour into the first use the unit's blue indicator light went off & the phone showed that charging stopped. It would not work again.
The vendor sent me another. It did the same thing. All together, I have received 6 of these that all charged for about an hour & died. So I took one apart to look for a fuse or other obvious sign of the problem. I was quite surprised to find a 3.6 volt lithium ion coin cell inside. The cell is showing 0.03 vdc when removed & tested. (In the attached photo, the circuit board with the battery is shown inverted. It plugs into the underside of the larger board.)
I am quite curious what the coin cell is used for in these chargers. I've got very limited electronics knowledge, but am reasonably familiar with power supplies of many types. I've never seen a cell inside one, so I searched around the internet for some clues. I came up empty. Could it have been for initial programming? If so, that seems like planned obsolescence- The programming would be lost when the battery is exhausted. (I am guessing...)
Do you all know what the coin cell is used for in these units?
Thanks For Your Knowledge!
Paul
I hope everyone is well & enjoying today!
I bought a 'charger' for my cell phone. It is 120 vac input & DC 5v out in the form of a USB connector. I plug in the included USB to Micro USB cable to charge the phone. About an hour into the first use the unit's blue indicator light went off & the phone showed that charging stopped. It would not work again.
The vendor sent me another. It did the same thing. All together, I have received 6 of these that all charged for about an hour & died. So I took one apart to look for a fuse or other obvious sign of the problem. I was quite surprised to find a 3.6 volt lithium ion coin cell inside. The cell is showing 0.03 vdc when removed & tested. (In the attached photo, the circuit board with the battery is shown inverted. It plugs into the underside of the larger board.)
I am quite curious what the coin cell is used for in these chargers. I've got very limited electronics knowledge, but am reasonably familiar with power supplies of many types. I've never seen a cell inside one, so I searched around the internet for some clues. I came up empty. Could it have been for initial programming? If so, that seems like planned obsolescence- The programming would be lost when the battery is exhausted. (I am guessing...)
Do you all know what the coin cell is used for in these units?
Thanks For Your Knowledge!
Paul