I bought two new batteries in April of 2018, I cannot find my receipt and they would not turn the engine over this morning ... How long is a battery warranteed ..?

Take them in and have them tested, then they will determine what is best

Every battery that you buy comes with a sticker , that stick has a date on it you can take it in as long as it hasn't past that date. Also if you have an o'Reilly card then the purchase of those batteries will be in their system.

Generally, they are 2yr or 3yr from the date of purchase. See if they are premium or extreme batteries, the warranty should have been save under a phone number........they can verify at the store