The use of Blood Points is optional and disabled by default. You must turn it on with the mod MCM or console command (see the Customization page).
You can only enable Blood Points if you are playing in Reverse Progression (stronger when fully fed).
If you want blood potions to grant Blood Points, you have to turn on "Blood Potions Affect Satiation" in the MCM or with the console command.
If you want feeding off the recently dead to grant Blood Points, you have to turn on
"Advanced Feeding" for dead bodies in the MCM. It will affect satiation when enabled.
When you first install Better Vampires, your Blood Points will be out of sync with your satiation stage - feed once to have the Blood Points set to their appropriate number. The Blood Meter (optional) must be enabled with the check box in the MCM and you can choose to have it displayed all the time, or briefly each time it changes. Blood Point cost and the size of your Blood Pool remain fixed throughout all vampire ranks. I saw no point in adjusting the size of your pool each rank while simultaneously increasing costs for stronger abilities. If I increased blood pool size, and decreased the cost of abilities as you increased in ranks it would unbalance the mod. | 
