Battery dying while turned off

On the latest firmware, battery is still draining while the unit is off for a couple weeks. I had a full charge in ZHills two weeks ago. Went to Eloy, tried to turn it on and it was completely dead. Unit had been off in my camera case the entire time.

I have noticed this happening in the past.

It’s not a huge deal that it’s dead most times, but storing the unit at 0 battery is REALLY bad for it and will kill the battery very quickly. This is my major problem with this… it will make this $400 unit unusable in the span of a year or less.

How are you guys handling this and/or the warranty issues with battery related problems since it’s directly caused by the firmware not behaving properly.

My dekunu lost about 10% charge in 3 weeks off.

Hey guys, The battery is an easily replaceable part but it is quite normal for it to deplete when powered off, this is a safety function of the battery to prevent damage to the cell when not in use for a period of time. For sure there are some improvements that we can implement to make that depletion less over longer periods of time. I am sure we have some improvements planned for the next rollout actually so watch this space. :slight_smile:
If you feel like your device may have an issue unrelated to normal behaviour, please send an email to and we can collect some logs and investigate thoroughly for you.

What is the expected discharge rate per day when powered off?

I’m not sure why that would be considered a safety function, since depleted batteries are the absolute worst thing you can do to a battery beyond physically damaging it. A happy battery is a battery between 20% and 80% of it’s capacity, with the nominal charge being 50%. Anything outside of those parameters damages the batteries. Keeping the battery at 100% is almost, but not quite, as bad as keeping the battery at 0%.

With no control over the discharge, and no control over the charge, this is basically intentionally damaging the battery. I can charge it and let it discharge to say 70% and then turn it off, thereby keeping the battery in good health. But if it’s discharging itself when powered off, there is nothing I can do to prevent that. I wouldn’t classify that as a safety feature, I’d say that’s more of a planned obsolescence to for the purchase of a new unit or something? I don’t think you guys have done that intentionally, but maybe you just aren’t aware of how battery technology works and best practices related to them? Because what you’re doing right now is about the worst possible decision to make for battery longevity. Please reconsider this design decision.

Turned off my alti this past Saturday at 80%. It’s Wednesday and I was about to go jump. Battery completely dead.

I’m about done with this altimeter. It’s just one thing after another and now I’m not going to be able to jump because of it.

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Hi Josh, please upload you device system logs so that this can be investigated.

  • connect to wifi
  • go to Diagnostics > syslogs
  • tap upload once and wait - do not be tempted to tap this button more than once, if you do the device will continue uploading system logs
  • reply to this post and let me know once you have done this


Same thing happened to me @Josh

I uploaded it, but not sure if it captured what you wanted. Not sure how often the logs turn over

After the last update this winter this problem has become worse for me

Same here, I’ve tested and 4 days while the device is off, that’s ~20% battery less. I’ve sent an e-mail and logs from syslog.

Once after leaving the Dekunu off for a longer period of time (a month or more) when turned on it was 0%.

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Hey guys, just a quick note here to let you all know that battery depleting while powered off is normal behaviour, if you have noticed an increase in depletion on the current firmware this does not indicate hardware issues and improvements will be made in future firmware updates. Thanks :slight_smile:

This behavior will destroy the battery. It’s impractical to expect the user to charge the battery every week, especially during the winter. Leaving the battery at a 0 charge state, which is basically what you are saying is normal behavior, will wreck the battery in a very short period of time.

Are you guys prepared to cover the cost of battery replacement? I suspect not… As such, it doesn’t make sense to have the unit discharge itself at such a high discharge rate when off.

Hi Josh, thanks for your concern, I assure you the battery will not be destroyed. There are safety precautions in place to prevent this. Again, as mentioned, we are working on new firmware, once it is available and your device is connected to wifi, you will see a notification to perform the OTA update.

Thing definitely got worse for me

I can’t turn the device on anymore on battery.
It turns on only with the cable but after few seconds it displays “low battery voltage” and it shuts down.
The battery doesn’t seem to charge because after few hours on the power supply it still have the same issue.

I should have the latest firmare, unless there’s been an update in the last 6 days

It looks very similar to this issue Battery will not charge

I just managed to upload a syslog

@mutley gave me a hand to fix this issue. I’m lucky he’s a local jumper! Thanks!

Any movement on this?

With regards to the battery being destroyed, that’s literally what’s happening right now. There are no safeguards in place to prevent it. Draining the battery to zero and letting it sit there for an extended period of time destroys batteries faster than anything else and you say that’s expected behavior currently.

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Are there any news @Tracy @dekunu-staff ? Last Saturday I made 3 jumps, and I turned off the device with still 60% of remaining charge.
Now I tried to turn it on to have it ready for tomorrow and I found the battery at 0% (6 days have passed).
As already mentioned, this problem irreparably ruins the battery !!!
I’m starting to get tired of this kind of problem …

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There will be improvements in the next firmware iteration, it is a big launch that requires a lot of testing, hopefully it is not far off, your device will let you know when it is available

Battery dead again.

Turned it off the day before at 63%, dead in the morning.

This thing is completely unreliable and the battery is absolutely trashed now.