@sfpoulcolin for every vote you cast your voting power decreases by 2% . It repleshes at a rate of 20% per day . Don't drain your Steem Power to levels below 80%. Your votes will have less effect (worth less) the lower your Voting Power goes

If you vote 40 times you just drained your voting value down to 20% .(40x 2% = 80%) if your vote is worth 0.10 at 100 % it will be worth 0.004 at 20% vote value % when you vote at 100 % .
It will also take you 4 days to replenish your vote back to 100 % .
Below is a copy of yours . You have 57.56 voting power and you will get back up to 100% VP ~> 100% in 2d 4h 15m | 2018-06-03, 00:45

With that all said how can you say
It won't drain your SP for the day. You can vote 40x @ 100% before your SP will drain.

Or did I misunderstand you ?