Tandem Tslim pump battery experience

Today I saw for the first time my pump battery charge level had dropped to less than 10% in just over 24 hours, since I charged it to more than 95% yesterday morning around 10 am. I haven’t kept good data but my gut reaction is this is a MUCH faster drop rate than I usually see. My experience till now has almost always been that a full or nearly full charge only drops to less than 50% in nearly 48 hours. What experience do some of you other tandem pump users see? I’m curious if I’ve got a pblm I need to discuss with the mfr.

Dropping that much in 24 hours is not normal. There was a problem with the t: connect app that was causing battery drain. It’s fixed now, I believe. Maybe do a phone update?
The issue is discussed a little here:

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That definitely seems way too fast. I thought my own battery was expiring faster than it should a while back, so I started keeping a log. Takes mine about a week to go from 100% to the alarm threshold (20%?). Which I decided was tolerable. I charged mine to 100% yesterday and it’s currently showing 75%, which seems a bit fast but not like what you’re describing. Of course insulin demand, and thus the demand placed on the pump varies, so that may be a factor.

Anyway, definitely contact Tandem. It would be good to keep a written log for a few days because they’ll ask you for whatever data you can provide.

I had this happen and Tandem support helped fix it.
One thing they asked me to do is to fully charge with connection to wall socket. I had been using USB hub and charging many things at same time. Its been awhile, but they also may have had me get latest updates first.

And I went back to using USB hub !! But know how to fix now.

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I had this happen once. Called Tandem. They gave me a gix over the phone that worked instantly. No up update required. I do seem to remember a recall a few months ago that addressed this issue.

I had a similar experience this weekend - after changing to my second Dexcom G7 sensor the Tandem iOS app stopped reporting recent (the past 2 to 4 hours) of CGM and bolus data and the battery dropped from 100% to 20% in 30 hours (that usually takes 7 or 8 days). The Dexcom app continued working, so at least I could see the CGM information that Tandem wouldn’t show me there.

When I called Tandem they asked if I was using the latest version (2.7.1) of the iOS app - the version that supposedly fixed the battery discharge problem. I was. They then told me that even though I have the “fixed” app I need to unpair the pump from my phone and then re-pair it each time I change the CGM sensor. That was news to me, but it immediately fixed the problem. But I wish I had known that beforehand instead of spending hours on vacation (of course this didn’t happen at home) figuring out what was wrong with my pump.

  • Greg

Welcome to TuD, Greg. I’m not a Tandem user but appreciate your persistence in fixing your Dtech. While you may have been robbed of precious vacation time, your experience will be useful going forward. And sharing your experience will save others having to call the Tandem help line. This is the kind of thing that non-Ds don’t fully understand!