Probably eBay. I buy fuses like that for work from allied.
It's a 3AG 25 amp fuse, looks like some kind of slow-blow, also looks like a nail wrapped in solder.
3AG only describes a glass tube fuse's physical size ...... meaning a size 3, American automotive glass fuse.
--------------
The direct replacement for the pictured fuse seems is a Cartridge miniature fuse; Time-Lag (T)612 series fuse .......and is to be rated at 250V AC and 25 amperes.
see http://www.betterfuse.com/MyUploadFi...t_20160620.pdf
You could contact the charger manufacturer for a replacement. If in a hurry, this may be an acceptable substitution though is rated at 32VAC:
https://www.walmart.com/ip/Ancor-Mar...02250/33277795
Last edited by Lou r Pitcher; 11-14-2017 at 11:52 AM.