Any E440 battery that works?

I have an old E440 here with a very worn battery, type 75. Lenovo originals no longer exist. Tried a 3rd party battery and got the "battery installed is not supported" warning from the BIOS, i.e. it will not charge and is useless. The 75 battery was used in loads of different Lenovos, I guess the cheapo brands don't bother testing every single type... Does anyone know a brand that actually works in an E440?