Individual solar cells are somewhat difficult to solder to. Self-adhesive metal stained-glass tape makes for the easiest soldering job--the tape holds itself in place while you solder. Use electronics solder that contains 2% silver. One side of the cell is (+), the other (-).
rain check (plural rain checks) (idiomatic) Any voucher or note from a merchant to a customer to provide an item the merchant has run out of at a later date for the item's current price, or (in a more literal sense) to provide a service at a later date.
Noun. 1. rain-water falling in drops from vapor condensed in the atmosphere. rainfall. monsoon-any wind that changes direction with the seasons. downfall, precipitation-the falling to earth of any form of water (rain or snow or hail or sleet or mist). raindrop-a drop of rain.