Yeah, E25 would be the software version.
Sounds like an older version of the software (not sure though). But seems newer is higher numbers. I believe only H28 and higher are safe for NiMH. You can send the charger into Tekin and have the software updated. I'm not sure what it costs.
I have an old Tekin BC112C (h27). I'd love to be able to still use that thing. But it just sits collecting dust. It was however the most robust charger I have ever used. It always worked.