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Technical question about battery use

Shozanahren
Level 3

Greetings!

Modern battery technology is as far from perfection as it can possibly be. Those batteries are very short-living ang got a finite number of recharge cycles, so I'm very concerned about prolonging my Quest2 battery life.
Linking via Thunderbolt USB-C port allows my Quest2 to infinitely maintain full-charge level even when playing the most demanding games, but I doubt if it is the healthiest mode for battery, or it just goes through constant never-ending cycles of charge/recharge, which possibly shortens battery life much faster than regular depletion/recharge wireless use via Air Link.
So, thats the question, which mode ôf constant use will allow battery to live longer?
1. Eternal link via cable (battery indicates as full during play).
2. Play via Air Link until in pings me about depletion (20%, afair)/recharge to 100%/play again.

1 ACCEPTED SOLUTION

Accepted Solutions

Hello there, @Shozanahren. Thank you for getting back to us so quickly.

 

To answer your question, it is better to let the headset die and then recharge it to extend battery life.

 

 Constantly charging the headset at full charge will damage the battery and reduce its lifespan.

 

Please let us know if this helps. Happy gaming!

View solution in original post

9 REPLIES 9

OculusSupport
Community Manager
Community Manager

Hello there, @Shozanahren. We wish you a fantastic day!


We understand wanting to get the most out of your battery experience. We are happy to assist you.


Feel free to follow these helpful tips to get the most out of your battery:

 

  • Power down your headset when not in use
  • Take it off the charger when its fully charged
  • Use the preferred cables and chargers.

 

You can also find more useful tips and steps here. We're excited to get you back into VR!

Thank you, but those are the most basic battery hygiene rules I already know and use with all my smartphones and other battery-using devices. When not in play, I always disconnect all links and shutdown the headset. And I do not use any charges because the headset gets enough power via Oculus Link to maintain its battery fully charged.
But that doesnt answer my question, which is more complicated:

a) Is it better to constantly cable connect with Oculus Link during play, or it kills the battery lifespan faster?
Or
b) Is it better for battery life to (almost) completely deplete it via Air Link and then fully recharge again?


Hello there, @Shozanahren. Thank you for getting back to us so quickly.

 

To answer your question, it is better to let the headset die and then recharge it to extend battery life.

 

 Constantly charging the headset at full charge will damage the battery and reduce its lifespan.

 

Please let us know if this helps. Happy gaming!

Thank you, that's the clear answer I needed!


@OculusSupport wrote:

Hello there, @Shozanahren. Thank you for getting back to us so quickly.

 

To answer your question, it is better to let the headset die and then recharge it to extend battery life.

 

 Constantly charging the headset at full charge will damage the battery and reduce its lifespan.

 

Please let us know if this helps. Happy gaming!


I'm sorry but with +20 years Lithium Ion and Lithium Poly battery management experience I find it hard to believe that the practise of continually dragging the battery to max discharge before recharging it is going to extend its life.  Best practise imho is to reframe from discharging below 30% since this is when cell temperatures start to rise and this will cause accelerated cell damage.  While I don't recommend leaving them on charge overnight, I don't believe that having them on full charge is going to make much difference if the packs are in regular use.  If they are not to be used for a while then the correct longer term storage should be done at around 40% charge.  I do think it's a good idea (but not really necessary) to take the battery level down to about 30% once every month or two before recharging.

 

My Elite strap with battery pretty well always maintains the headset battery at 100% and only uses it after the Elite strap battery is depleted.  If maintaining the headset battery at 100% adversely effected the headset battery's life I would have thought that a different charge/discharge algorithm would be used.

 

I have used this strap for 1 year now and I have not seen any significant reduction in battery runtimes for both batteries.  I do occasionally disconnect the Elite strap battery and run the headset battery down to 30-40%.

 

I think we tend to make these issues more complex than necessary.  As a consumer product I think that only a little common sense is required.

 

https://store.facebook.com/en-gb/help/quest/articles/headsets-and-accessories/product-care-and-best-...

 

https://store.facebook.com/en-gb/help/quest/articles/headsets-and-accessories/meta-quest-accessories...

 

None of these Meta Support articles mention much more than most consumers need to know.  Li ion batteries are normally considered perfectly fine until they fall below 80% capacity.  I suspect that unless users are continually leaving them on charge for long periods of time and/or are trying to use and charge at the same time with battery levels below 60-70% (creates more damaging heat) then they should last until the product is discontinued/unsupported (probably ~ 4yr lifespan?).  The good thing with the Q2 is that if it's headset battery capacity is reduced over time (which is inevitable) we can always use and external battery pack and/or with Link a powered link cable (eg. Kuject powered link cable).

 

https://www.amazon.com/Kuject-Separate-Charging-Ultra-Durable-Accessories/dp/B09TN25765

 

If any Oculus/Meta engineers want to dispute any of this, they should feel welcome to do so.  Cheers.

i9 9900k, rtx3090, 32 Gb ram, 1tb ssd, 4tb hdd. xi hero wifi mb, 750w psu, Q2 w/Air Link, Vive Pro


@TomCgcmfc wrote:

My Elite strap with battery pretty well always maintains the headset battery at 100% and only uses it after the Elite strap battery is depleted.  If maintaining the headset battery at 100% adversely effected the headset battery's life I would have thought that a different charge/discharge algorithm would be used.

That's the question: If headset takes necessary power directly from source (Oculus Link cable, regular charger, or powerbank - it only matters that incoming power should cover all needs), or through battery, which undergoes a constant charge/deplete process. It's like harmful situation you have mentioned: charge and play in same time.
I.e., for notebook it's a normal and natural to be constantly connected to power source, but for smartphones it's a very harmful way. And the initial question was about that, in which kind Quest uses incoming power: like notebook - directly, switching to battery when external power is off, or like smartphone, with battery as a primal source, and external power as battery charge.

@Shozanahren  I think you are overthinking a lot of this mate.  As long as you use common sense together with a basic understanding of how these batteries work it's all pretty simple.  While we may not follow the theoretical perfect practise, as long as we are following reasonable practices we should not have any problems during the lifespan of our Q2's imho.  This is the KISS Principle and it works best for most things, esp. VR.

 

To explain/clarify a few things for you;

I believe that when the Elite strap battery is supplying power to a fully charged headset there is only a very small trickle charge going to the headset battery so there is little or no risk of damage.

 

When talking about the potential problem of charging while discharging you need to understand how most smart charging systems work.  These are usually be part of the battery circuitry.  The usual algorithm for Lithium Ion and Li-poly batteries is for the actual charge rate to decrease once the battery reaches about 80%, and continues to decrease until the battery reaches 100%.  That is why it generally takes as long to top off the last 20% as it does to say go from 20% to 80%.  That's why it's generally ok to charge/discharge as long as your battery is about 80% to start off with.  If you start a lot below this you are in the higher charge rate area and this may create more heat and potentially damage your battery (little by little).  On top of this, most power system have overload/overvoltage protection cutoffs that may also rely on thermal sensing.  

 

BTW, there is no problem using most smartphones (like my iPhone 12 mini) while they are on an approved charger (Apple approved).  Like the Q2 it's still not a good idea to leave them on charge for long periods of time because even trickle charging may potentially cause some damage.  Probably not a big deal if you only do this once in a while though.

 

The Kuject powered link cable I mentioned in my previous post (and have mentioned a number of time over the last 6 months on this forum) has a smart charging chip that limits the max charge to the headset battery to 78% and this is a very nice safe limit to help maintain these batteries in very good condition.  Military installations that use Li-ion batteries that require the longest possible lifetime (~15 years) usually set their smart chargers that maintain battery levels between 40-70%.

 

Most decent external battery packs when used as a charger, will automatically stop supplying power once it senses that the battery it is charging is full.  I use this feature to charge my Q2/Elite strap with battery at the end of the day.  I use the 5v 2.1a output to do this.  If I need to do a long session standalone or with Air Link that I know will exceed the limits of my Elite strap with battery (say +4 hours, and not something I do very often) then I let the strap battery go down to about 85-90% and then connect an external battery from its 5v 2.1a charge port to the Elite strap battery charge port.  I think the longest I've ever done is about 6 hours at which time the headset battery was still 100% and the Elite strap battery was ~70%.  Again, not something I'd do very often.  For the most part, a topped up headset and Elite strap battery give me more than enough daily runtime.

 

If you take all the points I've mentioned into account I'm sure your Q2 headset battery will last for quite some time.  At least until the Q3 is released, lol!

i9 9900k, rtx3090, 32 Gb ram, 1tb ssd, 4tb hdd. xi hero wifi mb, 750w psu, Q2 w/Air Link, Vive Pro

Wow. That was just great and detailed info. Thank you! I just knew about the rule 40-80, i.e. to keep my smartphone battery charge in this range. But that doesnt appear to be practically possible with headset due to much shorter active time period available on battery. That chip on cable looks really great, with my smartphone I have to check that charge level manually, and sometimes missing the right range. 😞   I guessed that there should be an option to set charge limits on smartphone, but alas. 
For now, the circumstances I'm presently in are quite... tight. It's dangerous to stick a nose out of cover, let alone to get some new hardware, especially of such exotic type. I hope to survive it longer than my batteries (although there is a risk of total powerdown for indefitine time), but while there is still a chance, I'd like to prolong their life as well. So, what I got now is the aforementioned Link cable, which allows me to play infinitely with fully charged battery, some regular powerbanks(which I can use as pocket feed for the headset), and no the Elite strap. Could you give me a word of advice, which way of use is battery healthier with available means: to stick linked and powered on cable, or charge/depletion 20/100% cycle?

@Shozanahren   Sorry mate This is all I care to add to this seemingly circular, one-sided discussion.  Bye.

i9 9900k, rtx3090, 32 Gb ram, 1tb ssd, 4tb hdd. xi hero wifi mb, 750w psu, Q2 w/Air Link, Vive Pro