Reddit reviews AC Charger Power Supply Adapter Converter Cable Cord For Lenovo ThinkPad T440, T440p, T440s, T540p, X1 Carbon, X140e, X240
We found 4 Reddit comments about AC Charger Power Supply Adapter Converter Cable Cord For Lenovo ThinkPad T440, T440p, T440s, T540p, X1 Carbon, X140e, X240. Here are the top ones, ranked by their Reddit score.
BRAND NEW, NEVER USEDLength: 13.5 cmConnector A: 7.9 X 5.5 mm (Female)Connector B: Slim Tip (Male)Compatible With: Lenovo ThinkPad T440, T440p
Here you go, problem solved.
The new chargers and old chargers are electrically compatible- literally all that changed is the shape of the plastic surrounding it (probably because it was too thick for the Ultrabook ThinkPads- the inset hinges make it impossible to put the charger on the back).
The 720 15 has a proprietary Lenovo connector, and it draws 135W of power. They'll need to make their own power cable that connects to a standard 19V/20V socket at one end, and the proprietary connector at the other end, then connect it to a power bank that outputs 19 or 20V and supplies 135W or more.
Get adapter like this one
https://www.amazon.com/Charger-Supply-Adapter-Converter-ThinkPad/dp/B00T013J44
I could be wrong but I believe the Yoga 14 requires a 12V source to charge. You're battery pack is designed to charge mobile devices that require 5V.
There are a few 12V battery banks out there and you could use one of their standard laptop cables with something like this? Haven't tried it myself so can't say it would work with certainty.