i bought a noco genius g3500 battery charger on clearance sale 10 years ago for $30.
it will charge any type of battery. it won't charge a completely dead battery. you have to put a little juice in the battery first from a regular charger first.
i have revived several completely dead AGM batteries with it that others gave up on.

https://www.walmart.com/ip/NOCO-Genius-G3500-6V-12V-3-5-Amp-Battery-Charger-and-Maintainer/46605772

Last edited by Mr T2U; 06/27/20 11:20 AM.
perception is 90% of reality