Is My Car Battery Bad Because it Needed a Jumpstart?

Did you come out to your car, only to find the battery was discharged and you needed a jump start, either with jumper cables or a jump pack, to get your car started? That happens to a lot of folks and while it isn't normal, it does raise the question of whether or not your car battery is bad, because it needed a jumpstart. There isn't a clear answer to this question, because every situation is different, but we can tell you what to do next.

The first thing you should do is try to get your battery fully recharged with a battery charger as soon as possible. Some may suggest driving around and letting your vehicle's alternator try to charge the battery, but alternators are designed to maintain batteries near a full start of charge, not recharge deeply discharged battery. Asking an alternator to recharge your battery can put a tremendous strain on it, which could lead to an even more expensive repair bill associated with an alternator replacement.

What you should do is find a battery charger, connect it to your battery and let it run until the battery voltage is at least 12.6 volts. How long will this take? It depends on the battery and the charger. For instance, if a typical car battery is 50Ah (the amount of energy it can hold) and your battery charger has an output rate of 10 amps, a completely discharged battery could take five hours or more to recharge. Many chargers will taper amperage and voltage over time, so do the simple math and add 20%, just to be safe.

Once you know the battery has been fully recharged, you can have it load tested, to determine if the battery needs to be replaced. Most quality auto parts retailers offer free battery load testing and they can come out to your car and test it, while the battery is in the car. You can find a quality battery retailer in the search bar at the top of this page.

If your battery tests bad, replace it. If it tests good, you need to figure out why it became deeply discharged. Sometimes the answer is simple- you left a light on all night or the car had not been driven in two months and the battery wasn't being maintained. Other times, it may be more difficult to understand. Is there something on the car that is discharging the battery, like an aftermarket dashcam, car alarm or car stereo? A parasitic draw test might be a good idea. If you cannot perform a parasitic draw test, a dealership or local mechanic can do it for you.

All modern vehicles have parasitic draws. That's how radio presets and other functions are maintained when the engine isn't running. It's normal to have a parasitic draw, you just may need to understand how that draw impacts the state of charge of your battery. If you have a 50Ah car battery and the parasitic draw on your vehicle is 75mA, that means it will discharge the battery at about 1.8A per day (0.075 x 24= 1.8A). That means if the battery was fully charged and sat unused, it would take just under 28 days to completely discharge the battery (50Ah/1.8A= 27.8 days).

The best thing you can do to maximize car battery lifespan and performance, is to keep battery voltage properly maintained whenever possible. Regularly driving a vehicle for more than 15-20 minutes can allow the alternator enough time to maintain the battery. We also recommend periodic maintenance charging with a quality battery charger. Whenever a battery gets discharged below 12.4 volts and sits, it starts to sulfate, which diminishes capacity and lifespan. If you top off your battery once a month with a quality battery charger, you can extend battery lifespan and improve battery performance.

OPTIMA chargers come with quick disconnect cables, that allow you to remotely mount charging cables, so you may not even need to open the hood of your car to connect your battery charger. Just make sure to remember to disconnect it before you drive your car again! OPTIMA chargers are fully automatic, so they'll only deliver as much current to your battery as it needs and our push button display and LED light bars make it easy for anyone to charge their car battery.