Does "Lost Mode" drain the battery?

Yesterday, Friday evening, 😟 I forgot my phone at a bank, just a couple of minutes before they closed. When I track it, I can see that it's still there, so I know the phone is safe. I want to put it in "Lost Mode" so that I can put my husband's phone number on the screen. Hopefully they'll be open tomorrow, but if they're not, will the battery be drained by Monday morning?

I know I can go back in on Monday and retrieve it, but I it would be nice to know, does "Lost Mode" accelerate the battery drain?

Thanks,

Erica