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ChuwiHI13 and the Keyu battery charger

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szucsi|Post time:10-28-2017 00:10:17 View:1339|Reply:69

MemberChuwi| Post time 10-21-2017 05:51:04 | Show all posts
Edited by MemberChuwi at 10-21-2017 06:03

BTW, don't panic about keyu too much. The only obvious issue is when the plug cracks. Anything else is speculative concerning hi13 damages. However keyu is definitely dangerous to other devices.

You might wish to get an USB-C OTG adapter to check your Hi13 port first. As long as this works it's very unlikely that there is any physical damage.

I've charged my Hi13 many times with keyu and all is fine. But you can't risk to use keyu with a USB-C hub supporting PD or similar accessories.

BTW 2, concerning cost, I experienced that there is always significant additional expenses with any new devices for things like cases, memory cards, stylus, keyboard, extra chargers, adapters, apps(?!) and the like... it's a good idea to calculate 50% on top, especially with budget purchases... it's not a good idea to spend all of a budget on the main item, that does usually not work. Just my 2ct of course...

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David_S| Post time 10-21-2017 08:27:00 | Show all posts
MemberChuwi replied at 10-21-2017 05:51
BTW, don't panic about keyu too much. The only obvious issue is when the plug cracks. Anything else  ...

Thanks for your replies, much appreciated
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MemberChuwi| Post time 10-21-2017 09:23:52 | Show all posts
You're welcome. Not much going on here...  not too happy with all the USB-C oddities myself.
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MemberChuwi| Post time 10-23-2017 06:18:23 | Show all posts
Edited by MemberChuwi at 10-26-2017 15:03

Just to let you know what I ended up with... It's not really a recommendation but it seems to work.

PD charger:  Aukey PA-Y10  
47W USB-C PD charging, additional standard charging port.

https://www.amazon.de/gp/product ... 1_s00?ie=UTF8&psc=1


USB-C cable:  Choetech USB-C 3.1 Gen 2 (length 1m)
It's s bit more than necessary for charging but it is officially USB-C IF certified. The plugs show the SS10 superspeed logo. As many fully wired cables it's a bit stiff but not too thick. Plugs are of decent size, grippy and seem to be a bit easier to handle than the smaller counterparts like keyu's.

https://www.amazon.de/gp/product ... 2_s01?ie=UTF8&psc=1


USB-C 90° adapter: maxhood (2 pieces)
Definitely not a must but I liked the way these adapters reduce space needs for cabling. A bit pricey but with SS10 superspeed logo too and good reviews, so I think these little helpers are ok. No issues for charging found yet. Use the second one with USB-C otg cable, works ok too.
https://www.amazon.de/gp/product ... 2_s00?ie=UTF8&psc=1

Edit: found this much cheaper offer too late, seems to be the same 90° adapters

https://www.amazon.de/dp/B071GSQBG1/ref=psdc_1626220031_t2_B071XHCW5W



USB-C otg adapter cable: Aukey (2 pieces)
Basic stuff, works ok, USB-3

https://www.amazon.de/gp/product/B074K38QC7/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1


90° USB 2 otg adapter cable: cable cration (3 adapter cable set, one left, straight, right plug)
Cheap stuff but works good enough.

https://www.amazon.de/gp/product/B013G4DMCE/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1




90° adapters

90° adapters
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szucsi| Post time 10-24-2017 10:39:11 | Show all posts
Edited by szucsi at 10-24-2017 10:45

Inateck 45W tragbares USB-C Charger Ladegerät, Type-C Power Delivery
https://www.amazon.de/Inateck-tr ... sb-c+power+delyveri

Mackertop 65W Ersatz USB C Type c PD
https://www.amazon.de/s/ref=nb_s ... e-C+Power+Delivery+
I bought the Inatech charger, working excellently. If the connector is damaged. only the cusb-c cable should be replaced. If you can not communicate with the ETRONTECH PD Chip, you will not disable the system board because it will only have 5 volts. From this you will know that the cable is damaged and needs replacing.
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MemberChuwi| Post time 10-24-2017 11:34:09 | Show all posts
Edited by MemberChuwi at 10-24-2017 12:05

Fine if the Inateck works. I did not consider it because the text did not specify 12V compatibility. It's cheaper than the Aukey but USB-C only. The Aukey PA-Y10 offers a second standard USB charging port so I don't need more adapters or cables to use the charger with other gear which made the higher pricetag acceptable to me.

The recommended RavPower battery didn't charge my Hi13 as well. I've checked that with 3 different cables and the one that is shipped with the unit. Also not specified for 12V. Not sure how this battery can work for others here.

Maybe not all Hi13 are the same concerning PD charging?

I understand your point concerning cable replacement an initial protection. However, if the plug wiggles/crosses after 12V have been communicated and established I don't see much of a difference, it's the same risk. If you have a buggy cable it's even possible that a proper charger remains on 20V when you charged another device before with that request. Let's see if Hi13 can stand 20V... smartphones were fried by such cables that are as dangerous as the keyu.

After having seen so many odd things in videos and also recommendations here not working with my Hi13 I don't trust much in anything USB-C any more... including the Aukey charger I'm using right now. It seems to do the job, but who knows how long this thing works...

I personally would really have preferred no USB-C charging at all but a dedicated jack and usual type A USB-3 connectors. Go to shops and you will find nearly nothing USB-C thats worth spending money on. Most is about charging phones. If you really have some devices with USB-C how to connect some of them plus a charger to a single USB-C port? Haven't seen hubs with multiple USB-C ports (except charging).

USB-C is interesting for the future, but that has not arrived yet imho. Especially budget devices should have additional standard size USB-3 ports, micro USB is a pain too.

BTW, all sfuff I quoted worked just for me. Take it all with a grajn of salt. Finally one needs to verify for themselfes what works. Not all seems to work with any Hi13.



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amichael| Post time 10-25-2017 14:15:41 | Show all posts
My RavPower PB058 worked the first time I tried it, but I didn't know about the KEYU charger at the time and my connectors ended up bending.
The USB cable was long enough to fit, then. I suppose that means it also supplies 12 V, too, but I didn't see that information anywhere before I bought it.
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MemberChuwi| Post time 10-26-2017 15:08:25 | Show all posts
Strange. Did you have Hi13 1st hw revision ( Samsung MMC ) or the second ( Hynix ) ?

Anyways, RavPower battery does officially (website) not support 12V.
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szucsi| Post time 10-27-2017 21:58:18 | Show all posts
Edited by szucsi at 10-27-2017 22:02

Hi, It's no problem if the charger is 15 Volt. The Etrontech EJ USB pb controller can handle up to 24 volts. According to the manufacturer's specifications. At the same time, the wide use of this chip does not spread. This is not a coincidence because the USB-c standard is not designed for such a heavy load. The slim USB-c pins, 2-3 Amp charging current can not be twisted. It is soon oxidized, and then because of the increased resistance, the current will also increase. Because the current is determined by the resistance. I = U / R See Ohm's Law.
If it can not communicate with the charger with the usb pd controller, there may be two reasons for being damaged by the EJ898A Chip or eloxidized by the connecting pins. Provided the charger used is USB PD compliant.
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MemberChuwi| Post time 10-28-2017 00:10:17 | Show all posts
Edited by MemberChuwi at 10-28-2017 01:04

To be honest, l don't trust speculations with PD communication as long as I can't see a sniffer protocol.

PD is not about basic electric properties only. As far as I understand maximum current is statically communicated by a control voltage via dedicated pins. These are not prone to thermal wear the way you describe. The voltage increases (probably more details) are communicated dynamically (electrically its an ac overlay to the static voltage specifying max current needs). If this communication fails the electric properties are irrelevant. The charger sticks at 5V then and that's not enough to charge Hi13.

The oxidation may be true in general but because we don't know materials and any related data your hint remains speculative. There are 4 pins for Vbus and Gnd to spread current so even 3A results in just 0.75A per pin, assuming approximately even distribution. We also know that Hi13 does not use 3A but approx. 2A for charging, simply referring to keyu specs. This results in 0.5A per pin which is the same as USB 2.

Engineering is not about presenting formulas only, it's about interpreting them. The main current is not significantly determined by contact resistance (as long as it's not really extremely high) compared to the load we face here. To push 2A @12V total resistance is about 6 Ohms. I doubt contact resistance will ever reach 10% of this. Even with 5A (20 V) 100W USB charging we get 4 Ohms load resistance. There may be some tiny loss by the cable itself too, still how much total resistance do you expect? You seem also not to unterstand the models of voltage source and current source. A constant voltage step means current can not increase with resistance. Instead current drops. With increasing voltage drop you get of course additional power dissipation, resulting in more heat. To be honest, I've not experienced any significant warming with the plugs during charging yet. The charger warms up slightly, the tablet too. Nothing at all with the cable. I'm curious about your data or assumptions on resistance effects.

To me your explanation remains speculative referring to my experience RavPower's battery did not work to charge my Hi13. Its much more likely that it does not work what's not specified - 12V step. Because it is not officially supported it's prone to firmware changes in chargers, maybe some production batch works, another maybe not. That's my thought on any charger not explicitly specifying 12V . You don't know if it works with Hi13.

The fact that the stronger Aukey charges my Hi13 confirms that PD works with my device. Unclear is to me why the smaller one does not work. It should from electric standpoint but it does not from PD perspective. As it's speced for 12V and 2+A there must be a different problem. I think contact corrosion is very unlikely for complete failure, this would just explain heating plugs or slower charge speed only. I believe it's a PD communication bug... but that's also speculative without a sniffer protocol, it's just a somewhat logical conclusion that makes sense to me...

I don't believe in magical obscure assumptions without a proper evidence as long as there are simpler more likely options. However, magic isn't completely impossible either... just less likely - as long as we have no better facts

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