v8 (?) four flashing red lights, then one flashing blue one

Context:

The vacuum I’m using is not sucking.

I’m half sure it’s a v8 Animal.

Pushing its trigger shows 4 flashing red, then 1 blue light. I learnt 4 flashing red lights indicate that it’s a battery issue, but the blue light threw me off. 

Being a US model, the first three characters of the vacuum’s serial number won’t show up in the Singaporean Dyson website.

I see that there are Batteries D and E for this vacuum and that the E one is suitable.

Questions:

1. Is it a v8 Animal?
2. Is it a battery issue, or something else?
3. If it is a battery issue, is the Dyson V8 Battery E compatible with this Dyson vacuum? Otherwise, how do I resolve the vacuum not sucking?