For $75 we come to your car, test the battery's health and charge, check the alternator's output with the engine running, and look at the cables and grounds. Then we tell you what's going on in plain words. Sometimes that's "you need a battery." Often it's "your battery is fine, and here's what's really wrong."
Why a test matters
A slow crank, a clicking start, a car that's dead every Monday. Those all look like a bad battery. Sometimes they are. But we also find:
- A battery that's just discharged from short trips, not worn out
- An alternator that's barely charging
- A corroded clamp adding just enough resistance to stop the starter
- A ground cable that came loose
- Something staying on overnight and draining it
Replacing a healthy battery doesn't fix any of those. You'd be back in a week.
What we measure
Battery state of charge. How full it is right now. Resting voltage gives a rough idea.
Battery health. How much cranking power it can still deliver compared with what it's rated for. This is the number that tells you whether it's worn out, and you can't get it from a cheap voltmeter.
Cranking. How far voltage drops while the engine turns over. A big drop points at the battery, a connection or the starter.
Charging. Alternator output at idle and with the lights, blower and defroster on. Most systems sit somewhere around 13.5 to 14.8 volts running, though a lot of newer cars vary it on purpose.
Connections. Clamps, cables and grounds. We look, and we put a wrench on them.
What you get
A straight answer. If the battery's done, we can usually replace it right then, and the test is part of that job. If it isn't, we tell you what we think the problem is and who should fix it if it's not us. You can read up on the numbers in how to read a battery test.
When it's worth doing
- Your battery is two or more years old and summer is coming
- Start-stop quit working and the weather's mild
- You're about to leave the car parked for a month
- You're buying a used car and want to know what you're getting
- The car has been dead twice in a week
That last one especially. Battery dies overnight walks through the three usual causes, and battery, alternator or starter helps tell them apart.
Questions we get about this
If you replace the battery, do I still pay for the test?
No. When we replace the battery, the test is part of that job.
Can you test my alternator?
Yes, as long as we can get the engine running. We check output at idle and under load.