Revised With New Information: The Dexcom G6 Transmitter Battery Replacement

I just successfully replaced my first Dexcom G6 transmitter battery (after about 160 days of use, extending the life using XDrip +). I used this incredibly wonderful video…

I used an “Amazon Basics” brand CR1632 from Amazon which were NOT from shipped from an independent overseas 3rd party vendor. They cost $3.50 a pair. Many batteries that ship from these overseas vendors, although they are supposedly “name brand” such as “Maxell” etc are actually knockoffs and oft-times are DOA. Thus, since Amazon warranties stuff that it makes, and has excellent quality control on their house-brand batteries, I chose the least-risky route and used their house brand of CR1632 battery rather than the “Maxell” or “Energizer” batteries shipped from overseas…

In the video, after successfully replacing the CR1632 battery the instructor gives you the option of testing the battery by touching the 2 little “sensor contacts” with a cheap digital DC volt meter. A successful replacement is indicated by the voltage reading about 2.3 millivolts (a very small amount). This is the first test that you should do before applying the waterproofing glue.

I also devised a second test to make absolutely sure that the transmitter was working before applying the waterproofing glue. As soon as I put the new CR1632 battery into the transmitter, I restarted my Samsung S7 Smartphone and continuously scanned for new Bluetooth devices. The reason that I restarted my phone was to clear any previous Dexcom Bluetooth transmitter devices that may have been detected in the past.

The Bluetooth Low-Energy transmitter in the Dexcom G6 transmitter module transmits its “ID” (usually something like “Dexcom90”, “DexcomPQ” or “DexcomEY”) every 5 minutes, even if it isn’t installed or “started”. Thus, by using your cell phone to scan for 5 minutes (just press “scan” and repeat every few seconds till a new Dexcom device shows up in “Available Devices”), you can assure yourself that your Dexcom G6 transmitter is working, even before installing it…

As a result of this observed behavior, I conclude that the Dexcom G6 Transmitter module is using battery life even if it is not installed in a sensor and even if it has never been started or even installed.

Although the battery drain for an uninstalled transmitter is probably pretty low, it’s still doing an “announcement of its presence” every 5 minutes (which drains battery) and even when it’s not “announcing itself”, it is still running timer circuits etc and draining its battery.

The question is… how long can you store these Dexcom G6 transmitters before use and not have a significant loss of transmitter battery life?

I guess that since Dexcom warranties the transmitter for 90 days AFTER its first use that this is not a real problem, if the battery dies during the first 90 days, just call Dexcom and ask for a replacement…

You should be aware though that the Dexcom G6 Transmitter is actually running and scanning for a Bluetooth partner every 5 minutes, even if it’s sitting unused in its original shipping box…


What was your battery readings on your G6 original battery right before it died?
I am getting close to replacing my battery. I have batteries sitting, just waiting for my G6 to finally die. I already extended/reset the G6 date with Xdrip. And I have voltage A of 291, voltage B of 261, and resistance is getting up in the 1900s.

1 Like

My G6 Transmitter battery didn’t die. My readings were similar to yours. I was just getting an abnormal amount of “Sensor Errors” messages which stopped after I replaced the transmitter with a new one that had never been used.

I think that your warranty shouldn’t start until you actually use the device. I don’t store transmitters, though. I agree that might be kinda playing with fire for battery life. Thanks for the video post and your notes.

I’m the original post-er of this Forum topic…

Here’s some new concepts…

  1. Before removing your transmitter for battery replacement, always RESET IT… The transmitter life in XDrip+ etc is NOT reset when you replace the battery.

In XDrip+ Android do the following right before you “Stop Sensor” in preparation for replacing the sensor and getting rid of the transmitter with the dead battery:

a) Hit the little Eyedropper icon on the right side of the XDrip+ main screen… This will take you to the “units” screen. Hit the little Microphone icon on the “units” screen and follow the prompts and speak the words “ENABLE ENGINEERING MODE” into your phone’s microphone. Sometimes it’ll misinterpret what you’ve said and it’ll think that you said “and able engineering mode” or something. Keep repeating these instructions till it understands you and says “Engineering Mode Enabled – Be Careful!” on the bottom of the XDrip+ main screen.

b) Once you’re in Engineering Mode, do the same thing as you did in step a), except say “HARD RESET TRANSMITTER”…

c) Then, go to the “System Status” XDrip+ screen and wait up till 15 minutes for the “Transmitter Days” to reset to 0…

d) If the “Transmitter Days” doesn’t reset to 0 in a maximum of 20 minutes, repeat the previous steps…

e) Once the “Transmitter Days” is successfully reset to 0, stop the sensor in XDrip+, remove the sensor/transmitter from your body, break the sensor in half, retrieve the transmitter, and replace the transmitter’s battery (no big rush on this since you’ve reset the “Transmitter Days” back to 0).

  1. Here’s a great time-saver (it saves a big mess with waterproofing the transmitter with a bunch of glue…).

a) If you haven’t broken any of the transmitter’s mounting tabs, you’ll notice that the exposed parts of the new battery are facing downwards and are not truly exposed to the elements.

b) Because of this, you really don’t have to cover the entire battery and transmitter case with that messy 2-part epoxy glue.

c) Insert the unglued transmitter into your new sensor. Then, just put a thin coat of 1-part waterproof glue around the sides of the transmitter so that you’ve created a waterproofing shield between the inserted transmitter and the new sensor.

d) Since you’re breaking the transmitter out of each used sensor, and reinserting the transmitter into a new sensor (and re-glueing the gap between the transmitter and the newly replaced sensor), the small coating of 1-part waterproof glue will serve you so that you can reuse the old transmitter indefinitely (by replacing the battery every 90 days or do).

e) This is much neater that coating the entire underside of the transmitter with that 2-part epoxy since it’ll make the worn-out battery’s much easier to replace over-and-over-again since you won’t have all that dried-up epoxy to scrape off…

f) I use this GE silicone rubber glue since it cleanly peels off when you remove the transmitter from the discarded old sensor and doesn’t damage the transmitter’s plastic like Gorilla Glue might.


I agree, that given there is no “activate by pulling out” tab, the transmitter is using some battery even before being put into use. I would guess it’s in some low-power hibernate mode waiting to get attached to a sensor before it starts up higher functions.

The expiration date on the box of my freshly delivered G6 firefly transmitter is a little over one year in the future.

I would guess that as long as I use it by that date, that I’ll get 90 days out of it.

Given that the software battery-replacement deadline comes up weeks, or in some cases months, ahead of the battery’s actual physical depletion, there’s a pretty wide margin for error. I did have one (a G5) that I tried to extend using xDrip some time ago and discovered it was really dead, but the other times I’ve done that the transmitter has always had plenty of juice left. Wouldn’t surprise me if this is specifically to account for that little trickle of depletion affecting transmitter life over longer periods of storage.

1 Like

Great video and instructions.

However, I have some tools in stock that I think would work better than a drill bit.
A burr bit for die grinders or Dremel-style tools would work great! It would provide far better control of the grinding process, thereby reducing the chance of damage.

Here is a photo of one of mine (I have two sizes, one is shown)

Thanks Dave44… As I said before… The slower the better… And that burr bit idea is excellent. And remember to invest in a variable speed Dremel tool!

I’ve got a VS cordless Dremel. :slight_smile: A Rotozip. 2 air powered die grinders. As a former auto tech, I’ve got quite a few tools at my disposal, not to mention a garage full of woodworking tools. I know, I know, I’m spoiled!

Dave44 – I’m sick with jealousy for your tools! I’m not mechanical at all and I was able to successfully replace my transmitter battery. If I can do it, anybody can do it!!!

That’s a good pitch for your video (“if I can do it, anybody can do it!”). :slight_smile:

Having said that, since you are a vet, you must possess good manual dexterity.

I want to make it very clear to everyone – THAT IS NOT MY VIDEO!!! I just linked to it because it was VERY clear and simple. I disagreed with a few things that he did in it (most significantly gluing the entire battery area and using that Rolloc disk to grind off the battery cover), but all credit goes to “The Other Pancreas” for his superb video…

Ah, OK, I guess I presumed a bit too much! I also agree with a rolloc disk not being the best choice. :slight_smile:

If I were doing it, the xmitter would have been held down with hot glue rather than trying to hold it in my hand.

On the G5 I used the rolloc disk and two part epoxy. It didn’t take too long to do.
And each time after that, it only took me a few minutes to replace the batteries in the same transmitter.
The G6 is a little more technical so you don’t take off the little locking tabs, but other than that, I don’t see too much of an issue.

Hi Hammer,
Thanks for your comments on your work on the G5 transmitter… I have never seen a G5 unit, much less had one on my body, so your comments for G5 users are helpful…

That’s the problem that the guy had in the video with the G6 and the Rolloc Disk – he broke off one of the locking tabs by using that huge disk at high speed. Also, the Goodson brand Rolloc Disk costs $11.75 versus a few cents for a sanding cylinder for the Dremel Tool that you can buy at Walmart… Here is what I used at Amazon:

My glue idea is just less mess, less time to replace the transmitter battery time-after-time… There’s simply no need to cover the whole battery with 2 part epoxy and there’s no advantage in doing it…

That’s the same disc I use to trim my dog’s nails. Works great.

Sorry for bumping an old topic, but I had a few questions on replacing the batteries on old transmitters. I have several old transmitters lying around (some 81XXXX and some 8GXXXX). If I want to replace the battery on a transmitter, will it not work if the transmitter isn’t reset beforehand?

As far as I understand, it’s not possible to reset the 8GXXXX transmitters, but you can with the 81XXXX transmitters via Xdrip’s Engineering Mode->Hard Reset Transmitter command. My 81XXXX transmitters were used until the batteries failed them and have since sat unused for months, so I don’t really have a way to perform a hard reset before replacing the battery. My 8GXXXX transmitters were used for ~100 days until Xdrip gave me errors, but there should be some battery life yet in those transmitters.

1 Like

I cannot find this one in my country. Is there any other similar option?

JB weld works great. Or any water proof epoxy.