We've tested and reviewed products since 1936. Read CR's review of the DieHard 47 H5 car battery to find out if it's worth it.

How long a battery can power a car if the charging system fails. A higher score reduces the risk of failure if accessories are left on. A higher score means more reliable cold starts. This test ...

One of the most noticeable signs of a failing battery is a slow engine crank when you ... battery is losing its charge. A ...