I hate wasting products or throwing out things that work,plus I like to save a buck just because.
If you have a telephone at home,a wireless that sits on a charging base,you have a battery charger.
I just got new phones and noticed the battery in old phone was a 3.6 volt,NiMh battery.
Whatta ya know,my Eton/Grundig radio also has the same volt/type battery pack,and I dont have a charger for it.
So here is the battery from the phone,the pigtail connector plug is different from the Eton battery plug
I cut the pigtails off,stripped the ends and twisted all to the Eton Battery wires,then encapsulated the open wires in a blob of fast set epoxy,a fine way to attach low voltage wires very securely.The white connector is what fits the Eton,the black fits the phone.
And there you have it,the old phone is charging the Eton battery.Also cool the battery indicator on phone shows when battery fully charged,darn nice little charger leading a second life.Fun project.
The keys here are battery packs must be same voltage and same type,ie,in this case NiMH rechargeable,dont mix voltages or battery chemistry,they MUST be the same.