The battery represents roughly half of the price you paid for your NIU. So it should be maintenanced at least as well as the scooter itself.
[UPDATE: In 2018 NIU themselves published this page pretty much covering this FAQ entries content.]
- Optimal charging temperature: 10 to 35°C
- Using-temperature should not exceed -10 to 45°C
- Do not unnecessarily keep on charging the battery when it is fully charged (Green LED lit on charger)
- Do not completely drain the battery – try to charge at 10% at the very least.
(long term) Storing
- Optimal storage temperature: 0 to 20°C
- Recommended charge of 40-75%
- Check charge-level every 2 months (e.g. put it into your NIU to get a proper readout)
- Charge it to 100% when planning to use it again
To make sure you’re not “overloading” your battery you could use this engery-saving mains socket from Ansman (or something similar):
This automatically cuts of power when it falls below a certain (programmable) threshold, e.g. below 50 watts.