Fast charging support

[Varti]

Last updated: 8/3/2018

There are still some doubts on how does fast charging work on the Gemini , I'll post here what I have found so far:

- the Gemini can be charged using its power charger or an USB-C to USB-A cable, both of them are supplied with every perk.

- only the left USB-C port can be used for charging (both normal and fast charging).

- Planet has claimed that the left USB-C port supports Pump Express, Mediatek's own charging standard. Mediatek provides 3 versions of it: Pump Express+ (an older revision released in 2014), Pump Express 2.0+ (for lower cost MicroUSB and USB-C devices) and Pump Express 3.0 (for high-end USB-C phones). Judging from the supported voltages printed on the supplied wall charger, it seems that the only supported standard is Pump Express+.

- Compatible chargers: apparenly only Pump Express+ compatible chargers can be used. For comparison, both Pump Express 2.0 and 3.0 support Quick Charge 2.0 (a Qualcomm standard) chargers too, and Pump Express 3.0 also supports USB Power Delivery (an official USB 3.1 spec) adapters that support 3V to 6V at 5A+, plus any cable that supports 5A.

- Charging speeds: Pump Express+ devices can charge up to 75 percent in 35 minutes. For comparison, Pump Express 2.0+ devices take about 30 minutes, while Pump Express 3.0 ones take about 20 minutes.


A detailed review of all the available fast charging standard (not covering Pump Express+ though)  can be found on Digital Trends: https://www.digitaltrends.com/mobile/how-do...-charging-work/.

Thanks to potate, pakman, JamesKerr and Pete G. for most of the info provided here.

Varti

[Alius]

Thank you for this info!  To my knowledge, I have never had a device that supports fast charging, but it sounds great.  My current android phone is starting to die on me if I don't plug it in partway through the day, so the Gemini can't come any sooner

[Varti]

Thank you for this info!  To my knowledge, I have never had a device that supports fast charging, but it sounds great.  My current android phone is starting to die on me if I don't plug it in partway through the day, so the Gemini can't come any sooner

Same for me, never had any fast charging device before, and my smartphone is also starting to bite the dust. Perfect timing for the Gemini release

Varti

[speculatrix]

My current phone is an LG V20 and it supports fast charging, the qualcomm standard. I generally avoid fast charging it because it makes the battery warmer than normal which will reduce its life (not so worrying since phone's battery is easily replaced), but when I do need to charge it in a hurry, it's great.

I use a RAV Power charger, four ports of which one is fast charge. It seems very well made, not a lightweight thing, an older version of this:
https://www.amazon.co.uk/dp/B018Q7HNRQ
I would hope we can find something similar which does MediaTek fast charging.

I can plug non-QC devices into its QC port and they charge normally, so there's no risk there. Only if I plug my LG V20 with its QC feature, using a UCB-C cable, into the QC port will I get fast charging. Mostly I slow charge it off a different port.

[Mike D.]

What happens if you accidentally plug the charger into the right-side socket?  Does is just safely not do anything, or will it fry something?

[Mike D.]

the phone charges normally if I plug it into the QC socket, it's only if I use a USB-C cable with a device capable of using QC that it gets activate, so it is safe.

But what happens if you plug the usb-c charger cable into the right-side socket?

[Varti]

the phone charges normally if I plug it into the QC socket, it's only if I use a USB-C cable with a device capable of using QC that it gets activate, so it is safe.

But what happens if you plug the usb-c charger cable into the right-side socket?

This is an interesting question, and something I'd ask to Planet on their Indiegogo page. I have searched in Google for an answer, with no avail.

Varti

[speculatrix]

I deleted some of my comments and edited/clarified my original post about my QC-enabled LG V20, because I didn't want to muddy the water about discussing the Gemini and how it might do fast charging with the right kind of power supply.

[JamesKerr]

I deleted some of my comments and edited/clarified my original post about my QC-enabled LG V20, because I didn't want to muddy the water about discussing the Gemini and how it might do fast charging with the right kind of power supply.

From the specification of the included charger (specifically the voltages it supports), it appears the
Gemini is using PumpExpress+, an older version released in 2014.

See:

[img]https://www.androidpolice.com/wp-content/uploads/2016/05/nexus2cee_mediatek-pump-express-3-comparison.png\" border=\"0\" class=\"linked-image\" /]

There is more information here: MediaTek PumpExpress overview

That PDF states that there should be no additional cost in supporting PumpExpress 3.0 on the device, but that cables may be more expensive.

[Pete G.]

- it will be possible to charge the Gemini either using its power supply cable (supplied with all the perks) or an USB-C power supply charger (one is supplied with the All-In and Connectivity packages).

I don't think this is quite correct any more.  I noticed that when I ordered my unit (before the price increase) it specified a "Charging Cable", but after the increase it specified an actual charger, so I emailed Robin, and got this reply:

When we launched on Indiegogo we planned to only ship Gemini with a USB-C to
+USB-A cable. During the project we changed that to ensure every backer from the
+first, would get both a USB-C to USB-A cable and a wall charger. So your unit
+will also include a wall charger when it ships.

So I guess everybody gets a fast charger.

[Varti]

Thanks everyone for your comments, I have now amended my initial post. What I’d still like to understand is if the PE compatibility limitation is only dictated by the USB driver, and so if a software update might upgrade the Gemini to a more recent PE specification.

Varti

[sobukus]

I am not sure since when you consider charging to be fast charging, but it was noted in the Indiegogo comment section that the Gemini does pull 1.8 A from a normal USB power bank. Those banks can often do up to 2.4 A, but I am not sure which device really pulls that. I remember a Samsung phone only charging with the USB 3 standard 0.9 A (at least more than 0.5 A!) from such a power bank. So, for me it is reassuring to know that the Gemini at least does the normal more-than-plain-USB charging. 1.8 A is not that bad and means you can charge the device in around two hours (depening on how low you pushed the battery). Half an our of charging still should get enough juice for some hours of use, managing the time until the next charging opportunity when in a hurry.

Of course, not being able to charge from a connected USB C hub is really a drag and means that the Gemini is _not_ suited for a converged desktop experience using a docking station for large peripherals. It is a mobile device. So it is more phone than laptop to me … well, a PDA!

[Daniel W]

But what happens if you plug the usb-c charger cable into the right-side socket?

In short:Not much.

Since I own a USB type C power meter, I plugged that into the right-side port, and then plugged a USB-C cable from the Gemini fast charger into that. As any USB fast charger, it started at 5V, and since the right side port didn't explicitly request higher voltage, it stayed at 5V. Actually the Gemini did draw some power, about 360mA, which did increase a bit when I caused some CPU load (installing updates), but it never went over 500mA. Apparently, the Gemini can draw some power from the right hand port, but it doesn't charge, and as doing this isn't endorsed by Planet Computers, I wouldn't recommend keeping it plugged in that way. Something that shouldn't could get hot in the wrong way inside, so I ended the experiment within a minute, and yes, the port was fine afterwards.

[speculatrix]

Thanks, Daniel W, that's very useful to know.

[Grench]

Has anyone found an automotive fast charger that will work?