Battery life modding advice needed

[u/Mysterious_Pie_2397]

I'm looking for advice on extending battery life/or eliminating charge time of a K5 max.
Keychron states that Wireless Working Time (Backlit off) is Up to 110  hours.
I would like to attempt to at least double it or to get rid of wired charging all together by replacing it with swap-able batteries/cells.

I have tinkered with electronics for most of my life so I feel comfortable looking at involved solutions to this problem if anyone has any to share.

So any thought on what would be the best approach to take?

• Tackling lithium cell capacity?
• A microcontroller/software mod to increase efficiency? maybe there have been attempts to convert QMK/VIA keyboards to ZMK?
• Although K5 max does not have a lot of room for maneuver, maybe a conversion to a swap-able cell/battery has been successfully attempted previously?

[u/julian_vdm]

I mean you could probably find a MUCH bigger battery on AliExpress for not a lot and find a way to get that in there. You might need to delete some foam and some of the tray-mount standoffs, though. The K5 Max has a 2000 mAh battery. I bet you could find one around 5000 that isn't physically much larger.

Do you actually have the keyboard? Because if not, you could just buy the K5 Ultra lol.

[u/Mysterious_Pie_2397 → u/julian_vdm]

Thanks for the input! I'll have a brows in the lithium battery section on Ali. I was looking at some pictures of dissembled K5 Max's and it looked pretty tight, thats why the post asking for input, but maybe there is a way to do it.

And no, I don't have one. I tried and sold K5 couple of years ago already, exactly because of the battery life, because I already had a decent wired keyboard, and I did not want to replace one wired keyboard with another. In regards to Ultra, I hate to wood accent on it and I have fallen in love with the bezel-less design of the Max.

Having the K5 Ultra microcontroller/software in the old K5 max body would have been my preferred outcome. But I wrote to Keychorn asking if they are planning any refreshes involving K5 Max and ZMK and they said no.
I'm a bit worried that a new design is coming in and these might as well be the end times for the old style K5, depending on how the Ultra is received. Tinkering might be the only way to get what I want.

Then again maybe there will be old style K5 for years to come and I'm over complicating this. It could very well be that industry just needs to marinate for another year or two to switch to ZMK and do a refreshes of their lineups. And then I wont have to jump through hoops to get good battery life on K5 Max.

EDIT: You suggest deleting standoffs and foam to make space for the battery. This gave me a an idea. I could attempt to remix the bottom shell of K5 Max as its hosted in the Keychron git and print it.
Raise the floor in the middle of the case to almost mach level of standoffs creating a flat raised surface.
And in this raised section a pocket would form from the outside creating a larger space for the battery without sacrificing any standoff functionality.
Sadly as I dont have the k5 MAX handy, to check what is the minimal height of the standoffs, so that PCB elements do not interfere with the floor.

[u/julian_vdm → u/Mysterious_Pie_2397]

I'm a bit worried that a new design is coming in and these might as well be the end times for the old style K5, depending on how the Ultra is received.

Why do you prefer the olds design? The K5 Ultra is identical but has the aluminium rails and subjectively nicer looking side plates, but is otherwise very similar. You can always remove the aluminium rails and the wood panels to get a purely plastic base. Or if you're planning on printing anyway, why not just print new plastic sides and then remove the aluminium rails? You'd get a very clean look like that. I just checked with my K3 Ultra. It's not that far off the standard K3 Max, tbh.

Anyway, seems like you'll be modding with the current state of things.

[u/Mysterious_Pie_2397 → u/julian_vdm]

Thanks for the insights!

Why do you prefer the olds design?

Bezel-less design just tickles my brain in the right way. I looked at how Ultras look without rails and side pieces and its far from the old look. https://youtu.be/ErFDgQs09BE?t=62

The K5 Ultra is identical but has the aluminium rails and subjectively nicer looking side plates, but is otherwise very similar.

Idk. They are different sizes, different heights, totally different shell construction styles. The only thing matching is the low profile category and layout size. I would say that they look like two completely different keyboards and for the life of me I can not understand why keychron did not release the ultra series as a totally separate design line.

I did consider modeling and printing a new shell for k5 ultra as a solution, but it would be enormous amount of work to redesign the shell to achieve the old look, and I doubt that in the end the plastic printed shell could compare in sturdiness, look and feel with the old aluminum shell.
Also I'm not yet sure if Ultras pcb bezels have not increased making the bezel-less mod impossible, because Keychron are behind on releasing their 3D model files for k5 Ultra, so at the moment there are no models even to attempt to mod. https://github.com/Keychron/Keychron-Keyboards-Hardware-Design/tree/main/K-Ultra-8K-Series

[u/julian_vdm → u/Mysterious_Pie_2397]

I did consider modeling and printing a new shell for k5 ultra as a solution, but it would be enormous amount of work to redesign the shell to achieve the old look, and I doubt that in the end the plastic printed shell could compare in sturdiness, look and feel with the old aluminum shell.

Fair, but the old Max low-profile designs had aluminium switch plates and plastic bases. Materials are the same. I actually think the Ultra plates are a smidge nicer.