Hardware 3ds not charging

[TheTunaSandwich]

Bought a used 3ds charger online for my 3ds, which has been in storage since 2017, since my original one was lost. however, when i plugged in the charger nothing happens. i had a feeling that it was a dead battery, but i am still not sure. lacking the necessary knowledge to meddle with the hardware and stuff, what is a potential root cause and how can i troubleshoot this issue?

 

[KleinesSinchen]

Please measure voltage of the new charger and voltage of the battery.

Of course this is just a simple test when not applying any load on either one, but it is enough to see if something shows next to zero volts.