As an aside, if portable power tool makers introduced that derating idea in their chargers, one of the bugbears of good tools getting scrapped because of high replacement battery costs would be solved! I currently have 3 Makitas on the edge of extinction!
They are in the business of selling tools,
have a Milwaukee 18V ni cad tool kit out of service due to failed batteries, cost of replacing them is $90 each or about $140 for 2, the ni cads are obsolete but the tools are still good so going to bite the bullet as I miss the cordless Sawzall®.
