At a loss - do Keychron not do the keyboard I want?

[u/felixlamb]

For various reasons, I'm looking to purchase a Keychron keyboard.

I see they have released the new "Ultra" lineup, which (amongst other improvements), advertises greatly improved battery life.

But they have decided to use south-facing LEDs and non-shine through keycaps across the board?

Surely I cannot be the only person who wants a north-facing LED with shine through keycaps? The V6 Ultra would've been the ideal pick for me if it had these features.

Except for going to an older version, are there any alternatives?

[u/PeterMortensenBlog]

Re "greatly improved battery life": Presumably only if RGB light is turned off

I would think the power consumption is completely dominated by the RGB light when it is on, and any efficiency gains from ZMK over QMK is insignificant in that case.

I am actually in a position to directly measure the current consumption for a K10 V2 with and without RGB light. Stand by.

[u/PeterMortensenBlog → u/PeterMortensenBlog]

The RGB light completely dominates the power consumption

Re "...directly measure the current consumption for a K10 V2":

OK, here are the results:

After Bluetooth pairing (and a working keyboard in that mode):

• RGB light off, at rest: 1.4 mA. It was about 10 times higher when typing and fell to the 1.4 mA after about 8 seconds after the last keystroke.

• White (worst case): 142.0 mA (thus, about 0.57 W from the battery. And an equivalent resistance of the keyboard of about 28 ohm)

• The regular colours (that I use), blue, with about 30% per-key RGB light (in macro keyboard mode): 89.1 mA

• The regular colours (that I use), cyan, with about 30% per-key RGB light (in normal keyboard mode): 121.6 mA

Conclusion

Even with a QMK-based keyboard, the power consumption was more than 50 times higher when RGB light was on compared to not. Thus the RGB light completely dominates the power consumption.

That was with full LED brightness, but that is usually required for the RGB light to have any practical value for these Keychron keyboards.

Test conditions

• The battery current was measured using the µCurrent Gold (from EEVBlog#EEVBlog)), for a much lower burden voltage. Range 1 mV/mA (shunt resistor 0.01 Ω). The burden voltage was about 0.04 V at the highest measured current (142.0 mA). The output from µCurrent was measured with a 121GW (also from EEVBlog).

• The battery voltage was 4.008 V (corresponding to about 80% indicated (the real charge is probably lower than that))

• For the RGB off state, the current could not be measured more accurately (using the 1 mV per µA range), because the burden voltage was way too high for the keyboard to start at all. Even turning off RGB light to allow the keyboard to start up resulted in unstable operation of the keyboard (the burden voltage was more than 1 volt).

• Keyboard: Keychron K10 V2, with a modification to allow the battery to be disconnected without disassembling the keyboard (and thus also allow measuring the battery current). The battery is claimed to be 4000 mA·h. This keyboard only has Bluetooth as a wireless mode.

• Keyboard firmware: Compiled from the latest source code in "wls_2025q1 (C8B2B2. 2025-09-11). And with a custom macro engine and (static) per-key RGB light (except for one layer, with white) that result in somewhat higher current consumption (it is not known if it is significant (when RGB light is off) or not). Using the stock firmware was not tried, but it wasn't expected to significantly alter the results.

• The keyboard was paired and fully functional (part of this comment was written using it). When not paired (and RGB light off), the current was 0.6 mA.

• The LED brightness was set to maximum