What happened in Natural Cycles when my ŌURA battery failed?

Using ŌURA x Natural Cycles for temperature measurement could be the modern update needed for oral temperatures. But what happens when the battery fails?

This is part of an ŌURA x Natural Cycles blog series. Choose a link below to read other parts of the series:

Update March 2023: ŌURA released a firmware update for the ring that improved the battery issue I was experiencing. I don’t wear it during the day anymore, so I can’t say for sure if the fix resolved my ring’s issue, but I’m still using it to record my temperature each night. I’ve tested the Apple Watch (3 cycles) and TempDrop (briefly), and I feel most confident in the data from ŌURA x Natural Cycles, so I’m continuing to use it for now.

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In the middle of my 4th cycle with ŌURA x Natural Cycles, the ŌURA battery failed. Of course it had to happen around ovulation, right?

I woke up Saturday morning to a dead battery and no temperature measurements for Friday night. I had it on the charger Thursday evening while showering, but I didn’t remember if it charged to full, so I thought it might have been user error this time. I emailed customer support right away because I figured they can look at my device details to see if something went wrong. I charged it up again Saturday and went about my business, then I charged it to full again on Sunday. Tuesday morning, I woke up to a dead battery and no temperatures again!

Like I said, this was right around the time I expected to ovulate, so I really didn’t want any missing temperatures.

I went back to the message to customer service so I could follow up and found they had emailed me back quickly, but it didn’t get to my inbox. They sent instructions to help them see what was going on with my battery. So I told them it happened again and that I would follow their instructions.

They responded almost immediately again and confirmed that something was indeed wrong with my battery. They asked me to send them some information so they could check on the warranty. When I went back to find my order, I was disappointed to see that it was from October 2021, which meant I was out of warranty.

Luckily, I still have oral temperatures since I’m testing how manual charting compares to Apple Watch’s temperature sensor and ovulation confirmation, so that was a relief.

But this battery experience definitely put a damper on my overall trust in this partnership. I knew hardware failure was a possibility in the back of my mind, but it always feels a little different when it actually happens. And when it happens after only 14 months with the device, that changes things too.

What did ŌURA x Natural Cycles do with missing temps?

Interestingly, ŌURA x Natural Cycles still managed to confirm ovulation, even with 2 missing temperatures. I’m not sure if the data from the 8 previous cycles helped here, but customer service has told me the algorithm learns, so I suppose it’s possible. YMMV.

This cycle, I got a message saying I ovulated in a range of days (CD 16 to CD 18), with CD 16 being most likely. It also says the algorithm will confirm the actual day based on data in the luteal phase, but only after my period starts. That makes me wonder how they’re confirming ovulation (just using the typical length of my luteal phase and calculating it from there?), but we’ll probably never know.

If I were using Natural Cycles by itself and not charting manually, I would call ovulation the last day in the range (CD 18), watch cervical mucus, and closely follow the Symptothermal rules before considering myself in the infertile phase. Even after nearly 4 cycles with this app, I’m still skeptical of the whole “red light, green light” system, though I’m not sure why. I think I’m just suspicious of oversimplified things or that “just trust us” attitude in general.

As additional proof of Natural Cycles being cautious, the graph also shows a shadow around that range (see image below), which is not shown in my other graphs. I’m relieved to see Natural Cycles clearly making these distinctions and being transparent when they’re not sure. As more evidence of Natural Cycles being conservative, my guess is that CD 20 would have been a green day if not for that missing temperature on CD 19.

Overall, I’m glad to know it can still confirm ovulation (with some caveats) even with 2 missing temperatures at a critical time.

According to oral temperatures, I ovulated on CD 19; if I were basing ovulation on cervical mucus alone, I’d have marked it as CD 17. Interestingly, once I added my period, Natural Cycles confirmed I ovulated on CD 17. I’m curious if they took my average luteal phase (13.6 days), counted backwards, and called that ovulation day. I suppose my average luteal phase plus the biphasic temperature pattern (with 2 missing temps) makes for an educated guess, plus with my cervical mucus observations, I’m pretty confident CD 17 is correct.

Lessons learned

I learned a couple important things this cycle.

First, (unrelated to the battery issue) don’t blindly trust Natural Cycles when it comes to timing of testing. The last 2 cycles, Natural Cycles was spot on for when to test for LH: one cycle was positive the first day I tested; the other was positive on the second day.

This cycle was way off, though, and I knew it. I had peak fertile mucus from CD 14 to CD 17, and I thought about testing but didn’t. I waited to test until Natural Cycles told me (I’m not sure why) on CD 18. By this time, my cervical mucus had already dried up, and I knew I missed the LH surge and peak. Even though Natural Cycles confirmed ovulation this cycle, maybe with LH data, it may have been able to confirm ovulation sooner rather than giving a range until my next cycle starts. I learned my lesson and will test when cervical mucus is at peak rather than waiting for Natural Cycles.

Second, betting on ŌURA is exactly that: A bet. One could argue that an oral thermometer relies on a battery too, but an oral thermometer is easily and inexpensively replaced at the nearest drugstore or from Amazon.

ŌURA ships quickly if you’re ordering and already know your size, but if you’re filing a warranty claim, you may be waiting at least a few days to get it processed. And if you’re replacing a ring out of pocket, it may be quick but it’s certainly not cheap. Which leads us into the larger issue here…

Is ŌURA x Natural Cycles is still worth it?

My cost analysis of ŌURA x Natural Cycles was based on the ring lasting at least 3 years. If the ring lasts only 14 months (just outside the warranty period) as it did this time, the answer to “Is ŌURA x Natural Cycles is worth the high price tag?” for many would be a much more definite no — not with 2 app subscription fees and a hefty $299 to replace the ring every year.

If this battery issue is a random defect that has a low percentage chance of occurring, then I stand by my original conclusion that it’s worth it for me. In fact, my initial reaction was that I would continue with ŌURA x Natural Cycles while taking additional precautions:

Keep an oral thermometer handy for emergencies. It wouldn’t really work to use oral temperatures with skin temperatures to identify a shift. But because 1) I’ve been charting so long with oral temperatures, 2) I get the full picture of my cycle with cervical mucus, and 3) I know the cycle day, I would probably have a good idea if the temperature was in the pre- or post-ovulation range.
Always sync ŌURA temps and Natural Cycles right when I wake up so if the temperature didn’t record for some reason, I could still get a solid waking temperature orally.
Continue wearing my Apple Watch to sleep so it can also measure overnight temperatures and confirm ovulation. I’m all about efficiency, but sometimes redundancy is a good thing.

But if the battery issue is common, that’s another story.

Why I’m not replacing ŌURA after all

The more I thought about it, the more I realized that replacing my ŌURA ring to use with Natural Cycles didn’t make sense. Below are the major factors I took into consideration when I decided not to replace the ring.

1. This is too important.

This isn’t just tracking sleep, workouts, or steps. It’s birth control — multiple lives would be dramatically altered if it fails. I need to be able to rely on this technology.

2. The battery could fail on the replacement too.

A quick internet search for “oura gen 3 battery” brings up lots of complaints about battery issues for this generation. I read a few of the reviews and articles:

Someone mentioned using previous generations and that the Gen 3 ring has decreased in quality.
Some reviewers said they had to have their ring replaced multiple times due to the battery issue.
Some said it happened within 6 months and others were more than 12 months and out of warranty, like mine.

I usually don’t weigh reviews too heavily because we are only hearing one side of the story, and if something goes wrong, of course people are going to complain, but what about the million other customers who purchased the ring and haven’t said anything? Is this problem with the battery affecting 1% of rings or 10% or what? To make a really informed decision, I wanted to know what percentage of batteries fail, but I’m sure that’s not public information.

I found an article that said the original warranty was 2 years on the battery, but it’s now only 1 year. I don’t know if that’s reliable information, but if it’s true, that suggests to me that it was costing too much to replace rings for 2 years, which doesn’t bode well for this being a rare problem.

3. I never fully trusted it.

Even without the battery anxiety I now have about the ring, I still wasn’t convinced by the ŌURA x Natural Cycles partnership. You’d think after nearly 4 completed cycles with the pair, I’d be reasonably confident, but that wasn’t the case.

Again, considering the importance of this, it’s smart to be extra cautious. But after this experience with the battery, I don’t think I’ll be able to get to the level of trust required to take the leap of faith and stop using oral temps after all.

4. Tech I can’t rely on isn’t doing its job.

The point of using ŌURA to measure my temperature was to make my life and morning routine a little easier. This pairing was supposed to be a more accurate, effortless way to track basal body temperature and provide a second opinion on ovulation when my temperature shifts were a little ambiguous. But if I can’t rely on the ring, that entirely defeats the purpose of using ŌURA and introduces a whole new worry to my charting. At least with oral temperature, I know exactly what I’m getting into, and thermometer batteries and easily and inexpensively replaced.

5. Oral waking temperature is still a fine option.

Oral temperature isn’t perfect, but it’s fine. I’ve used it with the Symptothermal Method for nearly 8 years successfully, and I can continue doing that. Plus, I can input my oral temps into Natural Cycles if I still want to take advantage of the algorithm, too.

I’ll still keep an eye out for other smart devices in this space (I’m giving TempDrop another try, so stay tuned!), but nothing is wrong with oral temperature, and sometimes we can find value in simplicity.

6. The Apple Watch Series 8 supposedly does the same basic stuff.

The Apple Watch Series 8 tracks sleep metrics, measures temperature, and confirms ovulation. It isn’t approved for use as a contraceptive, but I wasn’t really using Natural Cycles for that anyway.

I don’t think the watch’s sleep metrics are as good as ŌURA’s, but I have years of ŌURA data. Unless I have some other specific reason to need excellent sleep tracking metrics, I don’t think ŌURA is necessary with the Apple Watch.

I’ve only had the Apple Watch for a few months, but from what I’ve seen so far, this first iteration is not something I would use on its own for ovulation confirmation. I’m still testing, but it might be great as a backup or confirmation if I’m not sure with noisy oral temperatures.

Also, it’s Apple, so future iterations will only improve. Stay tuned for my full post about the Apple Watch Series 8’s temperature sensors and ovulation confirmation!

7. I was kinda over it anyway.

I was already thinking about not wearing the ring when ŌURA announced their partnership with Natural Cycles. I wasn’t getting anything new out of it, and I also simply didn’t want to wear it anymore: The sizing was tricky, and the only finger it would fit on is the ring finger on my left hand — meaning I couldn’t wear my wedding ring as long as I wore ŌURA. Basically, I missed my wedding ring and wanted to stop wearing ŌURA so I could wear my wedding band again.

ŌURA isn’t uncomfortable, but it isn’t comfortable, either. The ring is thicker than normal rings, and if you’re like me and have smaller fingers and hands, you might be more affected by this than others. I’m much more comfortable without it, and I had to take an extra step to dry the inside of the ring and my finger after getting my hands wet (washing hands or dishes). If I didn’t do this, my skin would get super irritated. It’s a small thing, but think about how many times you wash your hands, then add this extra step to that.

For the convenience of no longer having to take my oral temperature in the morning, I was willing to continue wearing ŌURA. It was a pretty easy choice, actually. But now it’s just not worth it.

In closing

At first, I was pretty conflicted about whether or not I wanted to replace the ŌURA, but I kept going back to point #4 above. Essentially, replacing the ŌURA seems like more trouble than it’s worth — and at a high price. The ring is expensive enough that I don’t want to gamble on the battery being good.

ŌURA x Natural Cycles still might be worth considering for someone if oral temperatures don’t work for them, but since oral temps are generally fine for me, I’m calling it here and feeling grateful this happened early.

ŌURA x Natural Cycles doesn’t seem to be the solution I was looking for, sadly. My ring still works, but I don’t have the luxury of 4–7 days of battery life anymore. I was thinking of using it only at night just for the temperature, but I probably won’t because then I’d have to remember to charge it more frequently, in addition to remembering to put it on at night (and take it off in the morning), which again adds to my effort rather than reducing it.

When I started this blog, I hadn’t yet decided if I would replace the ring or not, but what was really telling is that I wrote this blog over a couple of days, and during that time, I stopped wearing ŌURA and returned my wedding band to its rightful place on my finger.