Lesson Learned: Don't wait on Transmitter Batteries


You probably won’t get it with the G4 if you change transmitters every 6 months, as recommended. Almost every G4 transmitter I had lasted nearly a year before I started getting low battery (and connection) problems.


We use them until they die, about 13 months on average.


So I dont see how the below is true. People change the batteries on these and keep using them. Now I’m thinking I’m going to pair mine with a different receiver and see if it lets me continue on. :slight_smile:

And you dont need to write down the activation date it will show you that in the settings menu.

The 90 day+grace cutoff is implemented in the receiver, not in the transmitter itself. The transmitter keeps right on merrily working until the battery dies. The receiver keeps track of transmitter serial #s (that 6-digit alpha/number you enter when binding the transmitter to the receiver on initial use of the transmitter), and stops accepting it after it expiration time period.


Ah nevermind, i see them replacing batteries on a G4 not G5. I also read where they tested the voltage on a G5 and the batteries were fine.

Anyone know where serial history is tracked at?


@Allen3, there was a link to a video detailing G4/5 battery change that was the best approach I’ve seen yet, on the xdrip+ gitter channel a week or two ago. I’ll find it and post the link here.

Basically, the approach was to use a grinder, with a type of attachment that ground the plastic resin on the top of the transmitter down, but didn’t grind away the metal contacts (or the top of the batteries) when it hit that depth, rather just seemed to polish them.

Made for a much, much, MUCH cleaner and easier to deal with “open” transmitter than the Dremel tool cutting method that’s in other instructional videos.


Yeah but from what I’ve read it’s not a battery issue for the G5 its a software thing where it does a hard stop. I even read a blog where someone disassembled one and measured and the voltage wasn’t low at all. So I dont see how battery replacement would fix that unless it’s somehow tracked in the transmitter and it gets cleared with removal of the battery power.


As a G5 user I can tell you the G5 does a hard stop. Doesn’t matter if the batter is really dead or not…it stops working. Now taking it apart and all that, I’ll leave that to people who have to save money or have some reason for needing to stretch out the lives of their transmitters. Insurance covers new so I just get new once the battery message starts displaying.


yeah would love that link if you find it thanks.


yeah my insurance covers also but a lot of people cant afford them so would like to help them if I can figure it out.


I save all mine, though. One never knows when that time will come when I may need to do some grinding/sanding/cutting myself. This info is definitely good to know!


Oh, sorry for the confusion. Yes, the receiver enforces the 90-day life of the transmitter. However, xdrip on android is reported to keep working past the expiration. I’m currently on my first transmitter with xdrip+, so won’t know for another 2 months what will happen.


I just learned that you cant use a G5 transmitter with a G4 receiver. :slight_smile: The serial number wont fit. So much for that test.


Yeah, and totally different radios anyway. So even if you could enter the ID, the receiver couldn’t “hear” the G5 transmitter.


Having a device that cannot be recharged in 2016 feels really bad

My guess is that having the battery not be rechargeable is the easiest/only (?) way to make it 100% water-proof/safe. There is literally NO entry point for water to get into the transmitter save for the two contacts that connect to the sensor, which I’m sure is just a DC voltage that’s way below 1A. A congenitally risk-averse FDA probably likes both of these things. :slight_smile:

And that probably cuts down on material in the long-run (not having to build a separate completely waterproof enclosure that can be opened), manufacturing costs, and weight. It might also get rid of any concerns about electronics failure. I’m guessing the failure rate probably is ABSOLUTELY zero for a 3 month use period - 18 months storage+use on the outside.

(See my other post about getting Pres. Trump on the regulatory case of idiotic requirements for PDM receivers.)

That said, does Dexcom have a recycling program? I’m actually going to keep all the the “extra plastic” that goes into the injector assembly for the sensor wire (the big tub, the plunger, and the two little plastic tabs/pieces that it says to pull off), and the used sensors themselves. In a box - for an entire year, which I’m planning to send to the Dexcom CEO along with a nice letter about plastics recycling.

As for the amount of e-waste in the transmitters… I’m guessing that ten years worth of transmitters (at the “standard” 4 per year) is STILL less material than is found in even a super-thin laptop.

Still, I want to know which compan(ies) are working on a way to take a used computer (or whatever), put it in an enormous incinerator for about a week to liquify the whole thing, and then separate out the plastic (hydrocarbons) from everything else.

And by everything, I mean EVERYTHING - down to the element level: copper from circuit board traces, lithium from the batteries, the minuscule amounts of gallium, arsenic, indium, other rare earths, etc from INSIDE the chips

Aluminum, iron, and carbon from case material (aluminum or stainless steel), boron and silicon from chips and glass materials (Gorilla Glass and such), mercury and other nasties from chips, light bulbs, displays… What other uncommon elements did I miss? :slight_smile:

Damn it, if we can enrich uranium - separating atoms that are three neutrons different. Surely we can figure out how to pull rare earths away from a veritable ocean of carbon, silicon, and aluminum. (And then separate the “ocean”)

Meanwhile, some on the U.S. Hill propose cutting funding for the NIH and NAS (Academy of Sciences), which might be able to fund such kinds of extreme “atomic recycling” research. Research that probably wouldn’t “bear fruit” in terms of true economic benefit for another 20 or 30 years at least. (Even if China decided to stop ALL export of rare earths, there are probably still plenty in other places for a decade or so.)

Though a quick search of “rare earth crisis that wasn’t”, I see that plenty of ink has been spilled on this. I assume someone has to be thinking about how to do such “atomic recycling”.

(Looking for an article I saw a while back about why the “crisis of 2010” never really materialized. Ah here it is, Council on Foreign Relations “Rare Earth Elements and National Security” Eugene Gholz. October 2014)


Jim - I came across your older post … and wondered if you ever learned anything about Dexcom planning to have a recycling program. I cringe every time I toss out the new sensor applicator/inserter thing… I wonder if we contacted Dexcom as a group rather than individually, would they actually consider it?


Thank you for sharing this useful information. This is my first post. My daughter(17 months old now) was diagnosed with T1D recently( three months ago). We just started using Dexcom 6 this morning. We noticed her temperature has been high since few hours after activation. Wondering if you have noticed the same thing. It could be unrelated but wanted to check. FYI everything else is normal. Looking forward to learning from your experience and that of others from the group as we are quiet new to this journey.



Hi @Cha, welcome to TuD!

Of course kids are metabolically different from adults, but I’d be very surprised if this were the case. The sensor filament is pretty inert as far as I know. If there were some kind of reaction I’d expect it to show up as redness, sensitivity and/or swelling around the insertion rather than a systemic response like a fever. I certainly haven’t heard of anyone reacting that way among the many Dexcom users who post here. But the way to be sure with any suspected problem is to contact Dexcom support. I’ve generally found them to be pretty helpful.


Dexcom G5 transmitter battery died after 96 days. Due to a mixup, they forgot to send us a new transmitter. There was supposed to be a new transmitter in our order of sensors, but they forgot to put it in.and we called at 90 days to find out if one had been shipped. It hadn’t and the battery was showing low. It took them a long time to get a new one out to us, and the old one died before it arrived.


I am on day 172 on the G5 transmitter using the Spike App for the Iphone! It looks like you can almost go 6 months if your lucky!


Same with XDrip. Some users on this forum and others have gone. +180 days on a single Transmitter.