Clean the top of the battery to avoid electrical discharge from condensation. Charge the battery once/month. Store it away from water heaters and furnace.
Rick
An ag13 battery can be bought at an auto store. You might also find one at a department store in the auto department. You can alone find one on the Internet.
Any Auto Parts Store will test your battery for free.
From your local auto parts store.
Have the battery tested at any auto parts store.
With a hydrometer which you can buy at any auto parts store.
You can test your battery with a battery tester. If you don't have a battery tester, you could take the battery to Advance Auto Parts and they will test it for you for free.
Drop it off at any auto parts store. If you want to get paid for it you can take it to a battery store.
Remove the battery and take it to an Auto Parts store. They will check it and tell you if it is defective.
Any Auto Parts Store, Walmart, Sears, Farm Store, etc
Dead cell in the battery or something is on pulling power from the battery. Have the battery tested at any auto parts store.
Clean the battery up with baking soda and water then fully charge it. Store it in a cool dry location. Recharge the battery every 2 months.
Have your local auto parts store test it for free.