The last big question on the G6 is “Can you replace the G6’s transmitter battery?”
Happy to report that you can, indeed!
I don’t have any fancy videos of it yet, because I was just focused on making sure I could do it vs. document it well on video. I have replaced loads of G5 transmitter batteries using the guidance on this great video. The same basics applied to the G6 transmitter work too…grinding down the grey plastic/epoxy, peel up the top tab carefully, and then pop the battery out.
However, I didn’t find the G6 quite as easy to replace the battery as with the G5. It’s definitely doable, and I’d get better with practice.
Here’s the note-worthy differences and things I learned:
The G6 only has one battery, not two. And the battery is accessed from the underside of the transmitter, as opposed to the top like the G4/G5 transmitters
The battery that the G6 uses is also quite a bit bigger than the G5. If you want to order replacement batteries for the G6, here’s a link for a set on Amazon. They are Maxell CR1632 3V lithium batteries.
The other major difference is that the battery (1) goes closer to the edge of the transmitter and (2) there are little wings to help the transmitter lock down inside the sensor. Both of those combined to make it just a little bit more difficult to do the grinding down to expose the battery.
Here’s a picture mid-grind:
While you are grinding, you have to make sure not to go too low on the corners above the little locking wing indents.
You also have to be aware that the top tab on the battery has a different dimension than the G4/G5 transmitters. The tab is much skinnier and has a few weak points built in…presumably to make the tab much harder to successfully bend up without breaking it. There are three weak points that I could see.
Therefore, I was trying to be especially careful on that edge-located weak point as I ground down. I did at first manage to get the 2/3 tab up just fine at first. But, in removing the battery next, I ended up losing the long end of the tab (it broke at the middle weak point pretty easily). The next time I do this, I will work harder to remove more epoxy around the edge weak point more carefully…will probably let me remove battery easier (see dicussion below) and maybe keep more of the tab. It’s going to be a balance though, too much grinding and you’ll take the whole tab off at the edge weak point. Based on the teardown pic though, probably salvagable if you did.
Battery removal was the hardest part. I think it’s really important to get as much of a clean edge around the battery as possible. Since the battery was much bigger than the G5 batteries, I found it was actually a lot harder to get leverage going to pop out the transmitter. There was a lot more resistance to popping out than on the G5. Possibly because I was too conservative on getting clean edge at first (definitely a contributor, I think)? Or maybe because I wasn’t using a longer lever to start? I don’t know…but eventually I did have to get out some vice grips and that made all the difference. Since I was able to hold the transmitter more forcefully, I could apply a better pressure. Worked SO well though, that it just popped super hard and fast. Oops. Did that little tab that normally sits under a battery go flying across my laundry room? Could have. I won’t know for sure until other people get a chance to open up their transmitters over the next few months. 😉
This is what it looked like when the battery was finally totally removed; a slightly shorter top tab (but still strong and in good shape) and a questionable bottom.
I assumed that there must have been a contact tab underneath that went flying. So, I ground out a little on the bottom to expose the contacts and put a little bit of solder down. Once I got that done, new battery was laid in and tab bent down to make contact on top again. I did use a touch of super glue to hold the top tab down, just to be sure.
And voila…it works. A G6 with a replaced battery. I sealed it back up with two-part epoxy and the transmitter is working well again.
Don’t forget to use the reset transmitter app to be able to use the official Dexcom apps after a battery replacement.
Nice work K. D. I wonder if there might be somthing abrasive enougj for the epoxy and not the metal. It would be a delicate balance tho. From my experience with roloc disks it might be a whole lot more work. I assume the roloc brish discs I get were counterfeit because they were hopeless tho.
Great!! Is there a way of creating a 3d printed shell for it? It could be amazing!
Step 1 in the process has to be write down the transmitter number before you start work, or you’ll grind it straight off. If that info isn’t in your receiver or app of choice and you didn’t keep the box, you’re stuck.
Totally agree! I’ll edit to add that. FWIW, Dexcom (if you order from them) will have the transmitter ID in your order history. Also, the box (if you saved it) will have the transmitter ID as well. But yes, without those sources or a photo…pretty hard to do. You could use a BLE scanner to get the name of the transmitter, but not the full address.
Re: ‘not sure what was here’.
I’ve gently waggled the battery of a G6 now and nothing was there. Most of the connector is buried in the plastic with just the 2 spot welds touching the -ve side of the battery.
I saw someone else’s tear down recently and there was a tab on the underside of G6 battery…so I suspect mine did indeed go flying.
I have found using a soldering iron to remove the last little bit of the grey material around the battery works wonders. It doesn’t melt it, but it flakes off like butter. Just be careful to not hold it on the battery too long or it might get hot and damage the electronics. Even if the top contact pin breaks, as long as it touches on the side you are good to go.
I did this and got a successful voltage reading on the battery replacement, then realized I wrote the sn down somewhere and now cant find it anywhere 🙁 its no longer saved in my xdrip app either since I was working on other transmitters in between this one. So dont forget to snap a pic of SN or record it somewhere safe prior to grinding it off.
Have you looked at your Dexcom order? My dexcom order has transmitter ID on it. Or if you still have the box from the transmitter?
Can you:
– Cut a curved door into the vertical, round, shallow end of the sensor
(Basically grind the battery end corners off… a C shape cut for the top & bottom of door and connect these with a 1/4″ vertical cut for the latch side of the door and 1/4″ vertical partial grind to act as a hinge)
-Slide/tweezer the battery out longitudinally from between the two contacts
-Slide new battery in
-Close door with epoxy. If 1/4″ vertical latch side cut is angled, so the back of the door is wider than the front, the door can be ‘latch’…
need an updated version for the 8x transmitter with the battery in a cage glued to the inside…..
I’m not bothering with that version because the transmitters won’t be able to be reset even after a battery swap. So, it’s pointless to replace the batteries on those.