No more overcharged batteries
A common cause of premature battery failure is over-charging. Many tools come with a charger claimed to be "automatic", either switching off when full charge is reached or going into low current trickle charge mode. Over many years I've had such chargers which failed to go into either of these states and have found the batteries too hot to hold.
My granddaughter's husband, being a caring type and knowing of my past problems has bought me a count-down timer, max. time 4 hours, so such problems should now be a thing of the past. Incidently, I've never come across these timers before.
Nothing but heaven itself is better than a friend who is really a friend. - Plautus