Maximum battery charge level for extended plugged in play sessions

[Toole]

A mode that enables a 50-80% maximum battery charge level to make the battery last longer for people who play plugged in a lot.

[AndryGate]

Originally posted by derFeef:

The Deck already does that automatically. You will notice the battery dropping to like 95% when you unplug a long session.

Not true. In my case there is no limit to the top up.

[maxRunner]

They mean after it hits 100% it will slowly start to self discharge. They think this means everything is great and the battery will last forever.

[terence4444]

I really need this function when I connect Steam Dock to my monitor or TV.

[~Senpai]

Originally posted by xep:

A charging controller is a perfectly reasonable feature to have for a portable device. I'd like to propose these additional functions:

1. reduce charging power based on battery temperature / steam deck temperature
2. 1-time charge to 100% for convenience e.g. activate before bringing the deck out

These are taken straight from the excellent acc software on android:
https://github.com/VR-25/acc

Since Valve has made the battery itself easily replaceable, there is less of a need to babysit the battery with the Steam Deck compared to a phone, but more under-the-hood tweaking of SteamOS is surely a good thing.

Scanned the thread and saw some discussion about updated scientific literature regarding li-on cell life: https://www.researchgate.net/publication/303890624_Modeling_of_Lithium-Ion_Battery_Degradation_for_Cell_Life_Assessment

In particular, refer to section B. Dynamic Stress Test Cycling.

Just need to correct you on one thing - The Steam Deck battery is categorically not easily replaceable.

[xep]

Originally posted by ~Senpai:

Just need to correct you on one thing - The Steam Deck battery is categorically not easily replaceable.

Thank you for correcting my impression that all of the Steam Deck was easily serviceable. This looks much harder than I expected.

Originally posted by KittenGrindr:

keeping the battery hovering around 90%

I'm not an expert, but the literature that measures cell degradation as a function of charge voltage limit says that charging a li-on battery up to 100% (4.2V) will result in fewer the discharge cycles before the cell experiences voltage related stress compared with charging it to 90%, and the same is true for 90% vs 80%. Li-on cells do not suffer from memory effects so shallow partial discharges do not affect its longevity.

A 30-70 cycle is ideal for me for usage and wear. 50 would be even better, but impractical for use unless plugged in. Based on the papers we want to cycle the battery at around 3.9V - 4V (60% - 70% charge). This is consistent with the other papers linked by others in this thread; the properties of Li-on batteries haven't changed, but we have improved our empirical understanding of how they wear based on use.

My Steam deck appears to quite happily charge to 100%, so I am manually controlling its charge cycling out of habit, and a charging controller would make this much more convenient.

[Boblin the Goblin]

Originally posted by maxRunner:

They mean after it hits 100% it will slowly start to self discharge. They think this means everything is great and the battery will last forever.

You need to fix your compulsory habit to lie about others. It can't be healthy.

[AndryGate]

Valve are waiting for you to see this fantastic news!

[Avocaz]

Has there been any response from Valve on this matter so far?

[~Senpai]

Originally posted by Avocaz:

Has there been any response from Valve on this matter so far?

Nothing yet. We just need to keep asking until we hear something about it

[AndryGate]

I use a 24Watt power supply at the moment, it's not much but it helps not to ruin the battery.

[PenguinYayOne]

Originally posted by AndryGate:

I use a 24Watt power supply at the moment, it's not much but it helps not to ruin the battery.

There is a way to slow down the charge rate to around 2W. This helps a bit but limiting to 0W would be the definitive solution.

"as root, write to /sys/class/hwmon/hwmon5/maximum_battery_charge_rate (max input current in mA). Range is 250 to 2500, default is 2500. If you write 250 here the battery will charge really slowly while still allowing you to play on AC power"
Source [github.com]

You can install power tools, which has a slider for this and the ability to apply the setting after boot.

[AndryGate]

Originally posted by Taki bácsi:

Originally posted by AndryGate:

I use a 24Watt power supply at the moment, it's not much but it helps not to ruin the battery.

There is a way to slow down the charge rate to around 2W. This helps a bit but limiting to 0W would be the definitive solution.

"as root, write to /sys/class/hwmon/hwmon5/maximum_battery_charge_rate (max input current in mA). Range is 250 to 2500, default is 2500. If you write 250 here the battery will charge really slowly while still allowing you to play on AC power"
Source [github.com]

You can install power tools, which has a slider for this and the ability to apply the setting after boot.

Thanks, I just tried the tools, they are great. We hope Valve works a definitive solution.

[Avocaz]

Originally posted by ~Senpai:

Originally posted by Avocaz:

Has there been any response from Valve on this matter so far?

Nothing yet. We just need to keep asking until we hear something about it

Yeah I filed a ticket and the 1st line response was less than encouraging, they didn't understand what I was asking for... Will update here once I hear more.

[Alex Atkin UK]

Originally posted by KittenGrindr:

As people have explain, modern hardware has limitors built in. Litium batteries have been improved on and optimized for a while now.

You will be saving negligible life implementing this feature.

If this were true why has Android recently added an 85% battery limiter? (at least its recent to my S10)

There is no getting around it, it DOES prolong your battery by not charging it to 100%. Its unlikely changes in battery design will ever fix this as its the nature of trying to push energy density to its limit.

Built-in limiters are set to avoid the battery exploding/catching fire, usually pushed to the upper limit for longer running time. Most people are more interested in that extra 10 minute run time so its optimised for that, not keeping a good charge for years to come. Being able to reduce the limit is not a lot to ask.

[AndryGate]

An option that makes the steam deck independent from the battery would be the best thing, it would make the steam deck a device to have in future models as well. we take laptop PCs, they can work without battery. If we can play completely ignoring the battery charging it would be very good. in this way there would be no need for a limiter, because we can choose when to ignore the recharge at the percentage we want. Also a limiter is not a good idea, considering that when the console is OFF, the limit will be exceeded. simply allow you to ignore the recharge and power the steam deck from the network.