01-03-2016 08:21 AM
Probably the simplest way would be to visit eBay and purchase a new cable and then spliced that into your old adapter / charger cord so you have the correct end.
This exactly is what I initially intended to do to produce a 12V DC car charger. But I read so much about people frying their devices. There seems to be some communication between the Yoga and the charger. As I understood it, the Yoga tells the charger either to deliver 5V or 20V on the same wire.
Read this before damaging your Yoga:
01-03-2016 08:50 AM
I was aware that the unit that plugged into the wall had dual DC voltage ability, but I wasn't aware that it extended to the cable that plugged into the laptop. It sounds like the handshake communication is what defines it and I don't how you would get around that. Fortunately your extra reading saved you some grief.
01-04-2016 03:05 AM
This company in the UK has an alternative AC connector available: http://www.laptopchargerfactory.co.uk/lenovo-yoga-900 (not advertising). They say it is tested. But I doubt it would manage to reproduce the handshake. Do you think it's safe to use? Is there a risk that 20V might be sent to the 5V circuitry of the Yoga 900?
01-04-2016 09:31 AM
Read the blog I linked above. They killed 2 Yoga 3 Pro by aplying 20V the incorrect way.
I´m afraid, the company you found does not offer chargers with the USB-type connector at all. In their products menu the have only chargers for some older Yogas. Their search function is pulling your leg. You can even order a charger for non existent models like Yoga 740:
01-25-2016 09:40 AM - edited 01-25-2016 10:25 AM
Was anybody able to modify the cable to get the external battery to charge the Yoga 900?
I saw the blog and the products from the mikegyver site. But wondering if there are other simpler solutions?
Would it be possible to make an adapter tip like the ones available for the other Yogas (Yoga 2)?
01-25-2016 10:23 AM - edited 01-25-2016 10:24 AM
For external battery, I just got a ChargeTech (27,000 mah) battery pack with an A/C outlet.
I was able to charge the Yoga 900 with it.
I also have a RAVpower Extreme 23,000 mah and would like to be able to use that to charge the Yoga 900. But there is no connector available!
03-04-2016 02:19 PM
i finally bit the bullet so to speak and cut my cable in half. there is a red V+ and a black V- cable in there, as well as a white cable. if you connect the white cable to the red V+ cable, it completes the circuit and you can charge your laptop by connecting the black V- to a power supply, and the white and red V- combo to the V+ of a power supply
03-06-2016 02:22 AM - edited 03-06-2016 02:25 AM
Can you confirm that you connected
white wire and red wire to +20V of power supply
black wire to ground of power supply?
Did you charge your Yoga this way saveral times without causing any damage?
Are there any more wires in the charger cable or just this three?
03-23-2016 08:54 AM
I finally bought a spare charging cable and removed the insulation for further investigation.
There are only three wires in my charging cable: black, white and blue. None of them are connected to each other.
With the cable plugged into the charger but the other end unplugged I measure:
5.37V between black and white
4.56V between black and blue
With the cable plugged into the Yoga but the other end unplugged I measure:
5.15V between black and white
0V between black and blue
4.29V between white and blue
With the cable plugged into both the charger and the Yoga I measure:
20.1V between black and white
3.13V between black and blue
I could not find out, how to switch the charger from 5.37V to 20.1V without connecting it to the Yoga. As there is probably no microprocessor in the charger, I do not expect any digital communication between the Yoga and the charger. Just connecting blue to white or black does not do the trick (the charger then stays at 5.37V).
Please Lenovo tell us how the charging process works. We really need to charge our Yogas from DC sources.