Most people think of cold weather as the battery killer. In the Sacramento Valley, summer does most of the damage.
What heat does
Under the hood, temperatures on a 100-degree day climb well past that. Heat speeds up the chemistry inside a battery, which wears the internal plates and dries out the fluid faster.
Why it fails later
A weakened battery can still start a warm engine in August. Then the first cool morning in October asks for more cranking power, and it can't deliver. That's why so many no-starts happen in fall.
What you can do
- Park in shade or a garage when you can
- Keep the terminals clean and tight
- Take a longer drive now and then so the battery fully charges
- Get a load test after summer if the battery is three or more years old
A load test takes a few minutes and tells you whether the battery will make it through winter.