Hi,
I've decided to do away with the original battery, and go for something bigger and crazier.
The battery is completely original, I could do a 40 km max range, and I've measured a usable capacity of around 2.5 kWh (3.9 kWh original).
Let me know if anyone is interested.
I'm located in the Netherlands, Zaltbommel area and regularly visit Amsterdam/Rotterdam.
Pictures will follow.