Renting flameless candles

Another option may be to check facebook marketplace or a few other areas where people may be selling "kits" of their wedding decorations. Similarly, if you buy these, you could sell them as a kit, to help recover the costs afterwards. But I have not checked with rental companies. These may be standard enough to rent.

Some rental companies do offer flameless candles. I'd suggest checking around to see how much it would be to rent vs buy in bulk. You can also try to buy them used from a local resell group, but my concern with used ones would be how much they'd already been used and whether the battery would hold up.