Charging a 21700 battery in a 18650 charger?

[AGZ]

Hi all
Was wondering if it was possible to modify a 18650 charger (e.g. by adding wires) to fit a 21700 battery or are the electronics different.
TIA
A

 

[fulee9999]

from the charger's point of view they are the same. technically all 3.7v li-ions are the same from charging pov

 

[AGZ]

Ended up building a 18650-sized battery adapter from wood with wires attached to either side. Wood cylinder goes into the charger, the wires touch on the contacts and attach to the 21700 battery. Completely removable and works great.