Follow either of these procedures:
Kia Niro 2017 (DE HEV) Service Manual: Components and components location
Component Location
1. Engine
2. Hybrid Drive Motor Assembly
3. Hybrid Starter Generator (HSG)
4. Transaxle
5. High Voltage Battery System Assembly
6. Power Cable
...
Kia Niro (DE HEV) Owners Manual: Battery recharging
Your vehicle has a maintenance-free, calcium-based battery.
If the battery becomes discharged in a short time (because, for example,
the headlights or interior lights were left on while the vehicle was not in
use), recharge it by slow charging (trickle) for 10 hours.
If the battery gradu ...