Droid 4: 4 Gold Pins Under Rear Cover – Successful 5V Charging at 1.5A

Hey all,

Connected a current limited power supply to Gnd and Vin on the back of my Droid 4 (pin lower right = gnd, pin lower left = Vin) at 5.0V and I had literal fast charging occurring. Screen showed charging, amperage was around 1500mA to start scaling down to 1300mA-1100mA as it reached full charge. It seems to pass through the Lithium Ion battery charging circuity so appears to be a safe way to dump in lots of power. Obviously these pins are designed to pick up power from the rear inductive charging cover that Motorola produced, but I wanted to try just pure 5.0V power.

I’m thinking of grabbing some extra rear covers and making up some drop-in charging stations or alternative inputs (like solar/etc.)

Nice to get away from having to charge on the USB Micro connector.

This seems like a VERY good thing if someone was building an external battery pack that fit onto the phone (like the one for the iPhone)…you could power it on, charge via this connector, and shut it down whenever you liked. The power draw on the phone drops off massively once it is charged so if you started with a full charge, it could float the battery all the way to empty.

Time to experiment 🙂

Again, for reference:

Bottom right (when viewing back, camera at the top):
Gnd is Lower Right – Nearest the microUSB connector
Vin is Lower Left – Opposite side from Gnd on the bottom row

Don’t hit it with too much voltage! I limited myself to about 4.8V and 1700mA max. 🙂

Cheers,

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2 Responses to “Droid 4: 4 Gold Pins Under Rear Cover – Successful 5V Charging at 1.5A”

  1. Mark R Jones Says:

    I was wondering what those may be. My Droid 4/XT894 has “kinda” bricked on me, a replacement is on it’s way but I am troubled by how much of my information is on the brick. I really want to dump that somehow before I send it in as part of the “exchange”. Your info may get me to the point of being able to light it up again. Thank you, I will let you know if it is a success.

  2. I was in the same position as Mark R Jones, and this worked for me! thank you so much! LOTS of private information I didn’t want to send back to the factory, plus many important documents I foolishly saved on the phone instead of the memory card. You saved my ass! Thanks!

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