Takuma battery pack voltage

Short version: Takuma battery pack shows 18V across the two main pins after a full 3 hour charge. All leds are lit up. Should one be able to measure the full pack voltage across the pins?

Longer version:
When i powered up the battery at the start of the day, the third blue diode remained off but the rest lit up.
It was fine (typical required 75% power to foil at a slow speed) for 15 minutes then i noticed the remote said the battery was at 2 bars. It had very little power after this. Full throttle had maybe 10kph.
Battery voltage was 15V and two diodes were lit up.
Charged pack, now all the diodes (including third) light up but voltage is only 18V

My apologies. The Voltage needs to be read with the battery activated. It reads 50.2 Volts when fully charged. Anything less than half battery remaining, does not have the power to get on foil.

Suggest you make contact here. Company has acquired Takuma

https://efoilsurf.ca/en/