Battery indicator and display indicator question

[John F]

My 36V 15A battery has 2 red lights and 4 green lights on the back which I can check after switching on the battery.

My handlebar display also has indicators to show the battery state.

Q1 What's the difference between the two?
Q2 Is one more accurate than the other?
Q3 Do I need concern myself?
Q3 and finally I still don't understand this battery management system. Do I have one? Where is it?!!!

 

[Deleted member 4366]

1. Ones on the battery, the other's on the handlebars
2. No
3. No
4. Yes. It's inside the battery case.

The battery indicator LEDs, whether on the battery or anywhere else, go off at fixed voltages, but there's no standard, although I'd expect similar bikes/batteries to behave in the same way. After you've used the bike a few times, you get an idea about how they behave, so you can make a rough judgement about how much battery you have left, or if somethings wrong- like you forgot to charge the battery.