I recently found my lost LED Lantern after one year in my old garage, but unfortunately it wasn't worked when I turned on.
I opened it and checked if the charging circuit was fault, but it wasn't because I tested charger circuit with another small sized rechargeable battery(I didn't know if it is lead acid or another) and battery had charged fine.
Then I though battery was fault and I was right, this 4.0V 2.0Ah rechargeable sealed lead acid battery even not charged with a power pack(I tried adjusting voltage from 3V to 6V even 12V, even not charged).
Its voltage remained 0V when I tested with my multi meter.
The Lantern is Rikon and Battery is a RB420C model, bigger than the good small battery I tested.
I can't think why this small torch battery which even not used for more than one year charged fine, but this wasn't.
Any help is needed me to determine what to do, replace bigger battery with my unsuitable small battery(because both batteries are very different) for the lantern or any step to take this dead battery back to life?
Thanks in Advance.