Thinkpad X61's power adapter plus an eBay adapter takes much longer to charge X270

sunhux used Ask the Experts™
I have an original Lenovo power adapter 65W 20V that was used for my X61 Thinkpad
& the adapter connects to the X61's round-shape power input: think the X270's USB-C
wattage is 45W & 19-20V only : correct me if I'm mistaken?

I have an office-provided X270 Thinkpad that I bring home but to minimize the weight,
I don't bring home (to reduce the weight that I carry) its power cord & adapter that
connects to a rectangular shape power input : is this called USB-C?


When I'm at home, I use an adapter to connect the X61's power adapter that I got
from eBay link above to power my X270 but this takes about double the amount of
time to charge up the flat battery of the X270 compared to the adapter that comes
with X270: is this due to the eBay adapter or the X61 adapter?

If it's due to the eBay adapter, can recommend a good one to enable faster charging?
I try not to get an original X270 power adapter & place at home as it may costs up to
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Dr. KlahnPrincipal Software Engineer
Fastest charging on modern laptops is usually achieved by using a genuine manufacturer charger.  This is because laptop manufacturers are fighting back against Chinese replacement chargers.

A genuine manufacturer charger usually has a one-wire communication chip built into it.  When the charger is plugged into the laptop, the laptop sends a challenge code to the charger.  If the charger responds correctly, then the laptop will charge at full capacity.  If there is no response or the response is wrong, the laptop will probably still charge, but at a reduced rate.

This is almost always the case on Dell and other manufacturers are now following suit.  So if minimum charging time is required it is best to get a genuine manufacturer charger.
Business Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018
Q1: The X270 has a rectangular power plug (not USB-C) to be thinner.  You need to use that adapter.

Q2: No, not USB-C.  Just a power adapter.

Q3: You can use this if the voltages are the same (I think they are).  I have an X1 Carbon here.

Q4: So long as the adapter puts out the rated wattage it should be fine. We always use the Lenovo adapters to avoid issue, but a decent quality adapter should be fine.


One last query:
in the attached screen, it show's 2nd battery:
does it mean X270 could support 2 batteries?
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018
Yes, front and back batteries. There were a number of Lenovo machines like that. You would want to do this via Lenovo Support if you want to add a battery as you would need to take the machine apart.
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Thanks and good luck with your Adapter.

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