Lesson Learned: Don't wait on Transmitter Batteries

So we’ve had our son’s CGM since April and had been using the same transmitter (we received 2 with the original shipment) since we started using the CGM. My understanding was that the battery ONLY LASTS for 3 months and that, when it shuts down, we should call Dexcom to get a replacement for it to have one in storage and ready to swap the old one out once the battery within it dies.

Not so. I just found out (perhaps we should have already known this???) that the battery has a 3 month “warranty” that begins from the date you activate it (use it for the first time). I called Dexcom this morning to see about replacing our old one which we had to change out on Saturday due to the transmitter battery shutting down, and they informed me of this. They’re talking about sending me over to customer service since the battery was “out of the 3 month warranty window”. We’re not even certain on the date that we began using it, but they said they shipped it at the end of April…somehow the transmitter worked an extra month beyond the 3 month window that I thought the transmitter stops working at? It would be wise to just keep tabs on that activation date even if you AREN’T receiving warnings, and just call it in to swap it within that 3 month window.

So, we told them we were going to dig through out logs and talk to our Doctor to find out what date we actually started using the transmitter since we weren’t sure…and we sure as hell don’t want to pay for another transmitter for something we didn’t even realize was important!

So, if you’re reading this and you’re new to using a CGM like we are, please a) Make note of the activation date for each “transmitter” when you activate it and b) CALL DEXCOM when you begin receiving warnings about the transmitter battery is running low so that they will replace it without issue since it will still be considered within the 3 month warranty window.

We don’t know the old activation date because we replaced the transmitter on Saturday when it died. We didn’t know we needed to know the old activation date information because we had not ever experienced this before and the importance of this somehow did not register with either my wife or myself.

So this post is just to anyone else, new like us, to make sure you call Dexcom within the 3 month window to get a transmitter replacement without any issues…we’re not sure what we’ll do, but the idea of paying $1000 or so for a new transmitter isn’t sitting well with us. :frowning:


First I always write the date I receive the transmitter on the box. That allows me to know the reorder dates, even if the transmitter is still working. Second, I can attest that Dexcom has been very generous with me when my transmitter died less than 3 months after installation. The G4 has a 12-month battery and that is something I look forward to going back too in December.

I also mark my infusion sets with the date so again I can keep track with a big visual reminder when I need to reorder. The G5 also displays the insertion date on the settings, transmitter information screen.

I agree. I find this new battery strategy by Dexcom nothing but a shame. Having a device that cannot be recharged in 2016 feels really bad. If they need money then they should increase the price of sensors or maybe increase the sales by offering lower price but by forcing one to change the transmitter so often is just not cool.

@Rphi2 - Now that I KNOW it’s something that we have to do, I; too, will be writing down and tracking my dates, etc., The post is about more just not knowing that it’s something that needed to be done. This post is about the transmitter battery going out and ending up outside the 3 month warranty window. They will be more than generous if you are under the 3 month window. The point of the post is to just inform “newbies” (like myself) that it is VERY important to track that date, and to make sure you call Dexcom BEFORE that 3 month timeframe is up.

What are you talking about with infusion sets???

I’m assuming the “Activation Date” and the “Insertion Time” are the same thing? Both are when you began using the new transmitter? The dates are the same date, the Insertion Time just seems like it provides a more precise date/time than the Activation Date.

I’m not sure why they do 3 months, but it’s something that is what it is and now that we know, we’ll just make sure we notify them in enough time to get a replacement before it goes out and before it’s no longer covered by warranty.

I am baffled… are you trying to get it replaced under warranty - why? None of any of this makes any sense. You get 2 transmitters to last 6 months… you order more 6 months after you got the first ones, NOT when the first one dies at 3 months???


Please allow me to try and unbaffle you. lol. Your statement is incorrect.

First, “Why would I try to get it replaced under warranty?” So that I don’t have to PAY to get another transmitter out of pocket. If you wait to get it replaced beyond the 3 month warranty window, they will not generously replace your transmitter for free.

Second, Your statement that you need to order your new transmitters after 6 months is WRONG. EACH transmitter has ONLY a THREE month warranty – EACH TRANSMITTER is independent of the other in that the warranty for each BEGINS which the moment it’s activated. If you wait 6 months to try and get replacements for one, or both of your transmitters, you’ll be out of warranty and will have to pay out of pocket for one (or both) of the transmitters.

I’m a bit confused about what you’re trying to do, too. It’s my understanding that the G5 transmitter has a 90-day warranty. If it fails before 90 days then you are eligible for a warranty replacement. But if it gives you more than 90-days service then you are not eligible for warranty replacement.

These transmitters are designed to shut down at about 112 days (90 + 22). Whether that was a good decision by Dexcom is another discussion.

If my G5 transmitter lasts more than 90 days then I feel that Dexcom has given me what they promised and I accept that I will have to pay (me + insurance) for the replacement transmitter. I suppose one could tell Dexcom that the 90 day transmitter failed on day 89 but I don’t agree with doing that, unless it’s true.

When I ordered my G5 kit, it came with two G5 transmitters. I just finished with my first transmitter and it lasted 112 days. I decided to order a G4 transmitter to replace it since the G4 transmitter, warrantied for 6 months, usually lasts 9-12 months or more. You must have a G4 receiver to do this but the G5 sensors are compatible with the G4 receiver. I still have one G5 transmitter in reserve.

Warranty replacement hinges on the date the transmitter stops working. Warranty replacement is not a function of simply calling Dexcom within the 90 days to request another transmitter. A less than 90-day failure must occur to make you eligible for the free replacement.

Am I missing something here?


Everyone is making my post FAR too complicating and missing my point.

My point of this post is to just advise people (BECAUSE I DID NOT KNOW) that the WARRANTY on each transmitter is 3 months. WHETHER OR NOT I should have known this…again, I probably should have known it, but being new in the Diabetes world there is still so much I don’t know. My post is to NEW PEOPLE WHO HAVE JUST RECENTLY BEEN DIAGNOSED and may not know (or overlooked) the importance of making sure you stay within the 3 month window with the transmitters so that you get the replacement without hassle. It’s something my wife and I didn’t know, we learned, so it’s just information I’m passing along to people so that they don’t make the same mistakes that we did.

Hopefully EVERYONE is un-confused at this point…if not, I can’t help anymore. lol

If your transmitter fails within three months (90 days) then you are eligible for a free warranty replacement. If your transmitter lasts more than 90 days then you are not eligible for a free warranty replacment.

Or is your issue about continuity of your transmitter supply and not about who pays for it?


Again, the post was only an informative post to advise people that the warranty RUNS OUT at the 3 month mark (something we did NOT know). If you fall within that 3 months (1st day - 90th day) then you get free warranty replacement. If you fall outside that window (> 90 days) then you don’t. I don’t have any issues other than in the not knowing the aforementioned information. Now that I know it I’m fine…I wanted to pass the information along to those newly diagnosed in case they overlook this small (but important) fact that they may have missed (as we did.)

Which is why my post subject line was “Lesson Learned” :wink:

Got it.

I think the reason people are confused is because your post can be read in a way that makes it sound like you plan to always call Dexcom and use the warranty to get new transmitters, which isn’t how a warranty works.

And, yes, unfortunately the new transmitters are expensive. Are they really $1000, though?! Yikes. It seems everything in the US is expensive. Here in Canada a new G4 transmitter is $800, which would be just over $600 in US funds, and I thought the G5 transmitters were that same price for two…


My apologies for confusing anyone…since I’m often times confused (even when I write things…because I’m still learning)…it might have been me asking questions out loud, or me maybe not even fully understanding things myself. But what I do understand is that transmitter warranty is <= 90 days and if you go outside it, you’re SOL. :smiley:

But, yes…my intent was originally to “use the warranty” to get a new transmitter but I didn’t realize I was outside the 90 days. I didn’t even realize they WORKED longer than 90 days…for some reason I was of the understanding that there was a hard stop date of 90 days…then on that magical day, you would call it in and get your replacement. It wasn’t until my own personal experience that I learned that this is wrong and they can go far loner than that…the rep told me of one case where someone used a transmitter for over a year (how, neither of us have a clue).

The rep was probably referring to a G4 transmitter. We’ve had a G4 transmitter last longer than (or maybe almost) a year. The G5 transmitters have a built-in “self-destruct” or “termination” date of about 112 days. Anything over 90 days is a “grace period” during which you should be able to order and receive another G5 transmitter so you have uninterrupted Dexcom service. And Terry4 is correct: I believe most people receive and pay for (either out-of-pocket or insurance plus copay) two G5 receivers at once. Health insurance will cover part of the cost of another two at some point during month 5 or so.

You can view a Dexcom G5 receiver as a very expensive tube of toothpaste. Hopefully, you remember to purchase another tube of toothpaste some time before you completely run out of the toothpaste in the current tube so you don’t miss brushing with toothpaste. But if there is nothing wrong with the current tube of toothpaste (other than the fact that it won’t last indefinitely), you’ve gotta pay for more toothpaste. Just like you’ve gotta pay for more G5 transmitters. :neutral_face:

1 Like

That’s about right. The G4’s are warranteed for 6 months and cost about $600 each, the G5’s sell in a 2-pack for about the same price, with each one warranteed 3 months. Why the G4’s don’t now sell for $300 each is beyond me, but nothing in medical pricing follows any logic. A huge difference between the two transmitters is that if the G4 goes past its warranty period, as they routinely do, you can just keep using it until the battery dies. The G5’s automatically time-out and you are forced to switch after appx 3 months whether or not they still have power. Not to be too cynical, but this makes me nervous that future generations of sensors will have some built-in, forced extinction too. I truly hope that’s not the case.


@ClaudandDaye - You have a lot of important things pulling at your attention resource. Looking after taking care of multiple children, including one with a recent T1D diagnosis, as well as earning living amazes me. I take care of myself and my dog. And I don’t have to go to work!

I completely get your fractured attention. You’ve absorbed a lot of detail in a very short time. You’re highly motivated, as most T1D parents are. You’re doing a good job. Over time things will become more routine.


I just hope most other things don’t cost me (monetarily) as this one did (or would, if we were going to buy a new transmitter). lol. I am all for learning, but Diabetes is already expensive enough without needing to pay out of dereliction or just not knowing something that I should have known, I guess.

We are planning on NOT paying for the >90 day transmitter. Instead, we’re just going to use the second transmitter until it reaches day 60 or 70 or so, then call it in and receive a replacement for it before the 90 days is up…then once the 90 days is up on it, swap for the new one that way.

Then when Insurance allows us new Transmitters (covered ones, that is), we’ll get more.