Can I use any charger on my ebike battery ?

The simple answer is no. 

What could go wrong? 

Best case scenario your battery will undercharge. So only charge untill halfway or not charge at all. Or blow its fuses and shut down. 

Worst case scenario, it could heat up and start a fire. 

Here in this video we're explaining and showing what could go wrong. Although the batteries look the same, the charges look the same. 

And the important job of the charger being correct for the battery and paired up correctly.