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 12.8V.
- 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 multimeter starting 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 goes 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.
Ready to purchase your battery pack? Explore our range of quality lithium batteries at Outbax for reliable, long-lasting power with every use. We also have a range of solar panels and solar charge controllers you can choose from.
Here at Outbax, we aim to provide adventurers and homeowners with quality power equipment at the best price tags. Whether you're upgrading an existing system, switching to solar for the first time, or powering an outdoor trip, this is your go-to online shop for everything you need to keep your essentials running smootly. Shop now!
Frequently Asked Questions
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What should the voltage of a fully charged 12V battery be?
A fully charged and healthy 12V car battery should read 12.8V. If you have a 12V LiFePO4 (lithium iron phosphate) battery, it will read slightly higher, at 13.5V when fully charged
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What is the process for measuring battery voltage using a multimeter?
To measure battery voltage with a multimeter, first disconnect the battery terminals. Then, connect the positive lead from the multimeter to the battery's positive terminal, followed by connecting the negative lead to the negative terminal. Once connected, switch on the multimeter to see the reading.
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What should a car battery's voltage be while the car is running?
Car batteries tend to have higher voltage readings when the vehicle is running, typically around 13.7V to 14.7V depending on the specific battery.
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What do different resting voltage levels mean for a 12V battery?
For a 12V car battery at rest: 12.8V is fully charged, around 12.5V is okay but should be monitored, 12.1V to 12.4V is partially discharged and needs recharging, and anything below 12.0V is fully discharged or "flat."
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My battery is reading 12.1V, what does that indicate?
A voltage level of 12.1V to 12.4V means your battery is partially discharged and requires recharging. Allowing it to stay at this voltage for prolonged periods can reduce its lifespan.
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At what voltage is a 12V battery considered fully discharged?
A 12V battery with a reading below 12.0V is considered fully discharged or "flat."
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What is a normal voltage reading during a car's cranking test?
During a cranking test, a battery in optimal condition should read between 9V to 10V as the engine is cranked up. A reading below this range could be a sign of a weak battery.
What are the typical voltage readings for a LiFePO4 battery?A 12V LiFePO4 battery has a slightly higher voltage reading than a standard car battery. For example, it would read 13.5V when fully charged and 13.2V at a 70% state of charge.
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What tools can be used to measure a battery's capacity?
You can use a multimeter to check battery capacity. Other devices include a Battery Monitor, which tracks amp-hours used, and a Solar Charge Controller, though the latter may be inaccurate for capacity when loads are connected.
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How does a Bluetooth battery monitor work?
A battery monitor is a device that tracks the number of amp-hours you have used to provide accurate data on the battery's state of charge. They can also display voltage and current, and some can connect to your smartphone via Bluetooth, allowing you to check all the metrics through a mobile app.
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Can a solar charge controller accurately measure battery capacity?
While a solar charge controller can measure voltage level, it can be inaccurate when it comes to measuring battery capacity, especially when the battery is connected to loads and chargers.
Do 100Ah lithium batteries come with a voltage display?Yes, the 100Ah and 200Ah lithium batteries offered by Outbax feature a power voltage display, which allows you to see your battery metrics at a glance.
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What are the consequences of a battery's voltage dropping below 12.0V?
If a battery's voltage is below 12.0V, it means it is fully discharged ("flat"). It should be recharged immediately to avoid damage and a potential decline in its lifespan.
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How do you properly connect a multimeter to a battery?
After disconnecting the battery's terminals, connect the multimeter's positive lead to the battery's positive terminal. Then, connect the negative lead from the multimeter to the battery's negative terminal.
