What Should a 12 Volt Battery Read When Fully Charged?

What Should a 12 Volt Battery Read When Fully Charged?

Have you recently bought a 12V battery? Regardless of what type of power pack you bought, it is crucial to know how much its voltage reading should be when charging, at rest, and while in use.

Voltage levels tell a lot about your battery pack's condition. This is one of the fastest ways to tell if your battery is dead or having some issues and can be measured with a multimeter. If you have a 12V car battery, here are the basic readings you should keep in mind.

  • A fully charged and healthy battery should read 12.6V.

  • A slight drop around 12.5V should be okay, but better to check it within a few days since you don't want it to drop any further.

  • A partially discharged battery that needs recharging would have a 12.1V to 12.4V level. See to it that you use an appropriate charger. Prolonged periods within this amount of voltage may cause a decline in your battery's lifespan.

  • Anything below 12.0V means your battery is fully discharged or "flat" and should be recharged immediately to avoid damage.

How To Measure Battery Voltage?

A multimeter is the most common way to measure a battery's voltage. They're usually on the affordable side, so no need to worry about additional expenses here.

The first thing you need to do when connecting a multimeter to your battery is to disconnect the terminals. Connect the wires from the multimeterstart with the positive lead from your multimeter to the positive terminal of your battery, then proceed with the negative lead and connect it to the negative terminal of your power pack.

Once all these are done, switch on your multimeter and check the reading.

Another thing to keep in mind about voltage reading is that car batteries tend to have higher volts when your vehicle is running. It will often be at around 13.7V to 14.7V depending on your battery. You will also notice that your battery voltage drops from its initial reading when you first start the vehicle. This is called a cranking test, which is a good indicator of your battery health.

A power pack in optimal condition should read between 9V to 10V when the engine is cranked up. If yours go below this, it could be a sign of a weak battery that needs replacing already.

What About the Voltage Readings Of LiFePO4 Batteries?

If you have a lithium iron phosphate battery or simply a LiFePO4 battery, chances are, you have a slightly higher voltage reading. For instance, a 12V lithium battery would read 13.5V fully charged and 13.2V at 70% SOC.

Aside from voltage level, it's also a good practice to constantly check on your battery capacity. This can be done with a multimeter too, but there are other ways you can go for it as well. Here are some of the devices you can use to track how much battery power you have left:

Battery Monitor

These handy monitors track the number of amp-hours you have used to give you accurate data on your power pack's state of charge. They also display voltage and current information plus, they can be connected to your smartphone via Bluetooth so you can check everything via a mobile app.

At Outbax, we have available 100Ah lithium batteries and 200Ah lithium batteries featuring a power voltage display. This way, you get to see your battery metrics in just one glance!

Solar Charge Controller

If you have a solar panel setup paired with a battery, you're likely to have a regulator as well. However, while this device can measure voltage level, it can be inaccurate when it comes to battery capacity. This is especially true when your battery is connected to loads and chargers.

All set to put that battery pack to use? Use this mini guide if you need a little refresher on voltage readings! If you haven't bought a battery yet, you might want to check on our lithium batteries at Outbax as well for quality, affordable choices. Shop now!

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