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Dexcom G4 Batteries Replacement

Introduction

This guide will show you how to replace the dead batteries of a Dexcom G4 "slim" transmitter.

The Dexcom G4 features a molded plastic body encasing two coin-cell batteries. Replacing the batteries will require grinding away the plastic over the cells, cutting them out, and refilling the excavated plastic with epoxy.

Be very careful not to damage the battery cells when grinding!

What you need

  1. Dexcom G4 Batteries Replacement, Marking the positions of the batteries: step 1, image 1 of 1

    • Take a marker and paint two circles at this position.

  2. Dexcom G4 Batteries Replacement, Slowly grind down to the batteries: step 2, image 1 of 2 Dexcom G4 Batteries Replacement, Slowly grind down to the batteries: step 2, image 2 of 2

    • Use the 2-3mm cutter and grind slowly down to the batterries.

    • Be careful not to grind away the contact plates.

  3. Dexcom G4 Batteries Replacement, Move up both contact plates with a screwdriver: step 3, image 1 of 2 Dexcom G4 Batteries Replacement, Move up both contact plates with a screwdriver: step 3, image 2 of 2

    • Lever both contact plates carefully with the screwdriver.

  4. Dexcom G4 Batteries Replacement, Cutting around the batteries: step 4, image 1 of 2 Dexcom G4 Batteries Replacement, Cutting around the batteries: step 4, image 2 of 2

    • Use a 0.5mm cutter and grind around the batteries. Be careful not to grind too deep. This process is only for loosen them and make space for the screwdriver.

  5. Dexcom G4 Batteries Replacement, Lever the first battery with the screwdriver: step 5, image 1 of 3 Dexcom G4 Batteries Replacement, Lever the first battery with the screwdriver: step 5, image 2 of 3 Dexcom G4 Batteries Replacement, Lever the first battery with the screwdriver: step 5, image 3 of 3

    • The lever part is easy but be careful with the lower contact plates. They are sticking at the (-)pole. Use the edge of the screwdriver and lever it carefully left-right-left ... till it's detached. Then push the contact plate down.

  7. Dexcom G4 Batteries Replacement, The same with the second battery: step 6, image 1 of 3 Dexcom G4 Batteries Replacement, The same with the second battery: step 6, image 2 of 3 Dexcom G4 Batteries Replacement, The same with the second battery: step 6, image 3 of 3

    • Insert wisdom here.

  8. Dexcom G4 Batteries Replacement, Assembly.: step 7, image 1 of 1

    • The original batteries are Maxell SR1120W (391) with a capacity of 55mAh. I suggest that you use the same ones because of the profile form inside of the transmitter. If you prefer to use another brand i can suggest Energizer 391 (60mAh) and Renata 391 (50mAh). First you have to scratch the contact plates with the screwdriver.

  9. Dexcom G4 Batteries Replacement, Attach the new batteries: step 8, image 1 of 3 Dexcom G4 Batteries Replacement, Attach the new batteries: step 8, image 2 of 3 Dexcom G4 Batteries Replacement, Attach the new batteries: step 8, image 3 of 3

    • Use superglue and sprinkle it at three points in the battery hole sidely. Then insert the new battery and push it down for 2 minutes. Same with the second battery. After this the (-)poles of the batteries should have contact with the lower plate.

  10. Dexcom G4 Batteries Replacement, Attach upper contact plates: step 9, image 1 of 3 Dexcom G4 Batteries Replacement, Attach upper contact plates: step 9, image 2 of 3 Dexcom G4 Batteries Replacement, Attach upper contact plates: step 9, image 3 of 3

    • First you have to scratch the upper sides of the batteries with the screwdriver. Then add a small amount of superglue under the plate and push it down for 2 minutes. Same with the other battery.

  11. Dexcom G4 Batteries Replacement, Check out for voltage: step 10, image 1 of 3 Dexcom G4 Batteries Replacement, Check out for voltage: step 10, image 2 of 3 Dexcom G4 Batteries Replacement, Check out for voltage: step 10, image 3 of 3

    • At this point, the transmitter should work again. Let's check it out and take the multimeter. Set it to 2000mV and add the measuring pens on the sensor contacts. It should show you 019. If yes ... congratulations! You can move to the next but one step. If not, there's a contact problem. First check the upper contact plates. Set the multimeter to ..

    • ...continuity. Touch one pen on the plate and the other on the battery. 000 should be displayed. If not, you have found the problem and have to remove + clean + re-glue it. If both plates have continuity you have to check out the lower contacts and remove the batteries again.Maybe pull up the lower contact a little bit before attaching the battery

  13. Dexcom G4 Batteries Replacement, Prepare 2K Epoxy Glue: step 12, image 1 of 2 Dexcom G4 Batteries Replacement, Prepare 2K Epoxy Glue: step 12, image 2 of 2

    • Slip on some latex gloves and add some 2K-Epoxy glue on a piece of plastic, glass or something else. Mix it about 2 minutes with a toothpick.

  14. Dexcom G4 Batteries Replacement, Sealing: step 13, image 1 of 2 Dexcom G4 Batteries Replacement, Sealing: step 13, image 2 of 2

    • Use the toothpicker to add the epoxy glue on the batteries and seal the grinded holes completely.After 2Std it's dried about 80% and you can insert it into your sensor pod. Wait 24hrs before showering. All done and have fun with your new transmitter. It should last now approx. 1 year again. After that ... you now know what to do. Cheers :)

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