Pocket Reform charging question

I understand that Pocket uses USB-C charging, and one of the fancy high-power modes.

Is it capable of charging, at obviously a (much) lower rate, from say average 2A, 3A 5V USB-C chargers? I’m buying the 60W charger and cable from Crowd Supply; I’m thinking of how I might fare while away from home and charger.

Assuming Pocket Reform is powered off, do y’all think I might get an overnight charge from a 2 ampere 5V charger?

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In theory, yes, but in practice it is not ideal and needs some firmware improvement (system controller FW). The current state machine wants at least 6V charging voltage and otherwise ends up in an on-off loop (with a few seconds in each state) trying to renegotiate charging.

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I’m aware it may have been answered elsewhere, but are there recommended chargers that work well?

RAVPower, Ugreen, Apple, PinePower appear to work fine.

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Thank you, got it. Not surprising, it’s a difficult problem.

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I’m also seeing weird charging problems on my Pocket Reform.

From the factory the battery showed 29% and barely moved anywhere when charging, max I got was 31%. Then following another thread here that mentioned a callibration issue, I just ran it empty, and now it indeed charges higher, but still doesn’t pass ~80% on full charge.

Using an Anker 735 GaN charger (65W).

Any suggestions? Should I drain it again?

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I had a similar sort of experience, but after a couple of “discharge 'til dead” cycles it now shows charging to 100%. I’m using the UGreen Uno GaN 65w Nexode Robot charger.

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Mine charged till 100% once I did like 3-5 empty/full cycles.

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I suspect it’s indeed a calibration issue where the battery charge and number displayed aren’t aligned. It seems the batteries are charged fully, but the displayed charge percentage gets stuck at some point.

What makes me say that is that I booted my Pocket Reform when it was at 17 % earlier today. It went all the way down to 1 %, and has been displaying that value for about 30 minutes now without giving in to emptied batteries.

It’s probably the ModelGauge algorithm in the battery monitor chip that first needs to learn the lower and upper charge limits. Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/max17320.pdf

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Thanks for that pointer. It says there (p. 62):

To determine the true accuracy of a fuel gauge, as experienced by end-users, the battery should be exercised in a dynamic manner. The end-user accuracy cannot be understood with only simple cycles. To challenge a correction-based fuel gauge, such as a coulomb counter, test the battery with partial loading sessions. For example, a typical user may operate the device for 10 minutes and then stop use for an hour or more.

That sounds interesting; I’ll use the charger accordingly. (So far, I’ve always kept the charger plugged in for hours, making sure it gets full.)

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Seems like not all Apple chargers work. I tried yesterday with a MacBook Pro charger and it did not charge at all.

Just for the record, I’m using these to charge my Pocket:

  • OK: Inateck PDS75-4UT01 5v/9v/12v/15v/20v, 3A.
  • OK: ShenZhen KunXing Technology FC57 5v3a/9v2.67a/12v2a (gpd pocket 2 charger)
  • BAD: Powerbank Walk Secretary Plus SBS100C 5v2.4a/9v1.5a/12v1a (reform charges at 0.01 or 0.02a rate)

@minute is the BMS on the pocket able to do cell balancing when charging?

Yes, same here:

  • BAD: Apple 30W USB-C Power Adapter (model: A2164)
  • OK: Ugreen Nexode 65W Charger
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I have a lot of chargers, most work fine when the system controller is on but not booted - but they refuse to charge if connected while the pocket is booted. If I plug in the charger before it is booted, it keeps charging while booted.

I have a strange behavior with a anker 100 watt pd charger - plugging it in while the device was on and booted causes the pocket to start charging - but also causes the display to turn off - it was not clear if the whole system halted as well.

Have you already updated the system firmware? Minute said that it would improve the compatibility with chargers significantly.

yes, this is with the latest firmware - I pulled it ahead of time from the latest build pipeline at the time.

So far this affects either only some pockets or some chargers. We still have to find out what’s different there (on my device this problem doesn’t happen, for example).

Looking at the state machine console logs - it never gets out state 0, it sees the CC1 and CC2 - and depending on orientation reports 3/0. it then times out in state 1