uConsole: How Does Charging Work?

Hi there,

So for charging your uConsole, is it true that you can only do this while the system is powered on? I recently tried to charge it while it was off, and it didn’t really do anything. So now I’m trying to do it while it’s powered on. Anyone know for sure what the best way to charge the system is?

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Ok! So powered on the machine, and when plugged in via USB-C, upower seems to be showing that the system is indeed charging. However, it seems to be doing so very slowly given that the running system is taking up a fair bit of juice. I guess since the system has to be powered on, there’s nothing that can be done to charge things faster?

Ok! So in checking out the system, I can see that the charge current is set to something quite low:

cat /sys/class/power_supply/axp20x-battery/constant_charge_current


However all my attempts to modify or change this value seems to have failed. Maybe someone else knows how to change this?

For what it’s worth, the Devterm also charges very slowly. Although there was a revision in the main board from Devterm to uConsole, I guess the slow charging aspect didn’t change.

Well, AFAIK the DevTerm can charge when powered off. The uConsole can’t seem to do that at all, unless I just didn’t wait long enough for the slow charging to show any effects.

The DevTerm can charge when it’s off, but there’s nothing to indicate that it’s charging. No led lights up, but given enough time the battery will gain charge. Maybe the uConsole does something similar and charges but doesn’t show it?

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Ah, maybe I just need to leave it on for a significantly longer time period. It would be helpful if other uConsole owners could chime in, but it sounds like many people are still waiting for shipments.

Edit: I should probably preface this with the fact that I have a CM4 installed in my unit. Maybe the core makes a difference in terms of your ability to change the charge current. Not sure.

I’ll chime in with the fact that I’m also confused about this too. I have both the devterm and the uconsole and even though the devterm didn’t have indicator lights (when turned off) that showed you when it was charging, you can tell when you powered it back on that it was charging…
The uconsole is a bit more nebulous on what its doing. Add to that the hibernation issue which causes it not to wake from sleep and I’m always confused on how much power I have with the uconsole…

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Friendly update so others can benifit:

If you edit or create /etc/udev/rules.d/99-devterm-charging.rules, you can use KERNEL=="axp20x-battery", ATTR{constant_charge_current_max}="2500000", ATTR{constant_charge_current}="2400000" to change the charging current level permanently.


bingo. I assume you’re running a CM4 core? If you look at the dmesg output, it complains that the kernel failed to set the constant charging current, which results in the lowest possible value (300mA).

A devicetree overlay update is required to correct the maximum allowed value.

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uConsole will charge when powered off. There’s just no indicator, which is kinda sucky.

Yep, CM4 core! I’m glad this is resolvable in software. It would really blow if it required 8+ hours to charge the device every time :smiley:

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If you charge when the unit is off, does this charge at the lowest 300mA value? Because the system is off, it’s not clear what it should use.

if you charge it off, it will use the default settings of the axp228 pmic, something around 2amps I think.

This udev rule doesn’t seem to change anything on the A06.

So if I understand your photos correctly, your saying you get more charge power stock when the unit is powered on, than off? And I guess that changing the current setting does nothing on your core?

The voltages are pretty close to the same. It does vary a bit up and down while charging. And yea, changing the settings do nothing on my a06.

11-14 Watts is already really good. Should be a fine charging speed with that.

Yea, I’ve got no complaints.

When I tried this, I was surprised at how fast the charging speed became! thank you