It’s always nice to have extra batteries on hand for smoke and carbon monoxide detectors. Be ready when they start beeping with a 12-pack of Insignia 9V batteries from Best Buy. Normally $14.99, these are marked down to only $8.99 right now!
You may be able to pick up your order for free at your local store, depending on availability, or get free shipping on orders of $35 or more.