DIY - Battery status check, end of life or just cold? 2004 Honda Accord EX

This recent cold has really done a number on my gf’s car and its ability to start. She tends to not drive it everyday and it continues to be problematic when trying to start it. I’m assuming its directly related to the cold weather as I’ve had issues like this before, but would like to confirm her battery isn’t at its end. I have a multimeter, is that all I need to check the status of her battery to see if it is in need of replacement? What is the best way to diagnose her battery status?

We have a battery backup in the trunk we have had to use to get the car started recently, so I don’t think there is any issues with the starter in case anyone asks.

2004 Honda Accord EX

Anyone nursing the last few months out of a battery is on a fool’s errand.

After driving the car for a while, enough to warm it up and then some. Car off, check battery voltage. It should be 12.4 to 12.6 volts. Start car and check again, it should be 13.5 to about 15.7 volts, if you see that, the alternator is good. Let the car sit overnight, car off, check voltage. It should be over 12 volts, likely 12.2 to 12.4 even on an older battery. Leave the voltmeter in place, start car, does it start up OK? Does the voltage drop below 9 volts? If it doesn’t start easily and or the voltage drops below 9 volts, your battery is likely in need of replacement. If it does start OK and voltage stays up, let it sit another night and see if the battery drops below 12 volts as it sits. That may mean you have something shorted in the car drawing the battery down between starts.

Most auto parts stores have a battery tester that can load check it for free, and they’ll likely remove and install the battery for you. Drive the car a bit before stopping at the store. If it load checks OK, you have a short causing a drain on the battery, most likely.

Short drives in winter are super hard on an aging battery (heck, any battery). It doesn’t have a chance to fully recharge.

How old is the battery?

Buy a cheap battery tester and do a load test; it will show you what reserve the battery has. I paid $28 for such a tester. It will also record the voltage, as others recommend and these two readings will determine whether to replace it. My 2007 Toyota battery reads still in the green, but I will replace it before next winter.

Also, make sure battery terminals are clean and tight. If the battery is 5 years old just replace it.

Voltage is not necessarily an indicator of battery strength. Many auto parts stores will check your cranking amps for free.

The battery was an unknown number of years but greater than 4, so I just went ahead and replaced it. It works fine thus far and I expect it was just past it’s time.

Thank you for all the feedback and suggestions.

I suspect you’re right.
Happy motoring.