What voltage should the FitBit Ionic's battery supply -- 3.8V?

[multiverse]

I opened my FitBit Ionic to test the battery because it won't turn on after going to bed with a full charge.  FitBit support couldn't get it to work, and FitBit won't fix it for me, so I have to fix it myself.  I measured the battery voltage at 3.8V while it is out of the non-functioning watch.  Is that nominal, or should I replace the battery? 

If it's not the battery, I probably won't be able to replace any of the circuit boards because I'm not sure about the availability of the boards for the "Special Edition", which my model is.

Thank you.

[Rich_Laue]

That is the normal voltage for a lithium cell

[multiverse]

That is interesting and helpful.  Now I just need to know if the Ionic's battery is a single cell or not.  Thanks.

[Rich_Laue]

Here are 2 videos. 

Replace battery

Moderator edit:  removed Links

[multiverse]

Hi Rich, those are the videos I used to get to my current situation, with a disassembled Ionic not knowing which part(s) to replace.  They are indeed good videos, but they offer no diagnostic information.  I would really like to know if my battery is the problem, or defective circuit boards in the watch.  The battery is the only thing that is cost-effective to replace.

[Rich_Laue · Accepted solution]

The battery should be about 3.8 volts, even under a load. 

[multiverse]

Thank you again, Rich.  Before I throw my Ionic in the trash and boycott FitBit for failing to stand behind their product (on multiple occasions), may I ask how you know the nominal voltage of the battery?

[Rich_Laue]

That is the typical standard voyage of a lithium cell a few may be as low as 2.9 but they are very rare. 

https://batteryuniversity.com/learn/article/confusion_with_voltages

Is your ionic still under warranty? 

[multiverse]

How do we know how many cells are actually in the battery?  Isn't it true that some batteries have more than one cell, so they can supply a higher voltage than that of a single cell?

My Ionic is not under warranty any longer.  FitBit has refused to fix it on multiple occasions, the first time was only a few months after the 1-year warranty was over.  Now it is much later, and the watch is totally dead.  It has had many software problems throughout its life, starting as soon as I got it, and now this fatal hardware problem.

[Rich_Laue]

Yes their are batteries with multiple cells but the breakdown of fitbits point to single cell batteries or multiple cells in parelel. 

As for repairing, Fitbit does not maintain any repair centers, but a search will bring up a few 3rd party companies. 

[multiverse]

It is not worthwhile to get the Ionic fixed.  I checked the price and it is better to just get a different device.  Since FitBit doesn't offer anything similar to the Ionic, even after all this time, and they just tell me to buy a new one, I have no choice but to go to a different maker other than FitBit.

I don't understand what you mean by "the breakdown of fitbits" pointing to single cell batteries.  I have scoured the internet and there is no information on this battery.  I would like FitBit to answer this question about their battery, or to find an authoritative information source.  This is three-hundred-dollar decision.

[Rich_Laue]

Currently Fitbit still smells the ionic, which replaced the Surge. 

Since I'm not con earned about built in GPS I love the Versa 2. 

[multiverse]

I contacted Joe's Gaming & Electronics (the maker of those videos showing how to disassemble the Ionic) and they confirmed that the Ionic's battery voltage is 3.8V.  Therefore, it must be one of the circuit boards in my Ionic that has failed.  It's going in the trash where it belongs.  Too bad, it was the Special Edition, too.  

FitBit's lack of quality and support for their own products has spawned a lucrative side industry for third parties to fix their questionable electronics.

[sxotty]

I am glad to see this information.

I had a fitbit ionic that died after 11 months, it just quit charging, but was still on until it wasn't because the battery died. 

Replaced under warranty.

The warranty replacement died after 13 months.  In this case it was 43% on the battery, but the watch hung between too screens.  I set it on the counter and figured it would sort itself out in a bit.  In the morning it was also black screen.  I think a run away process drained the battery until it was non-responsive, but charging and all trouble shooting failed.  Fitibit offered a coupon to buy another, but that is obviously madness when they fail so often.

So I too took it apart as well.  My battery on the replacement is reading 4.29V.  Care to explain how that could happen when you are saying it is supposed to be at 3.8V?  I know usb is 5V so perhaps the charging board broke and let it charge endlessly, or perhaps the 3.8V assumption is wrong.

[Rich_Laue]

In general a lithium cell is 3.8v.

Sorry I dont work for Fitbit. Ifixit has a teardown 

[sxotty]

No worries, I don't blame you of course, but it implies to me that somehow the charging circuit is broken, or doesn't work correctly in that watch.  I have not take the original apart yet, and I might just skip it if I decide to buy a watch from a manufacturer that is reputed to make more reliable products.  I am pretty disappointed with how short the lifespan was on a watch that did most everything I wanted.  Other brands I would consider are more expensive but they would need to last 3 times as long to be the same net price, but that should not be hard.  I want a watch to last like my timex has for years.  I have old laptops my kids are using that lasted over a decade as well.  I do not know why these are considered disposable.  They are not to me.