LiFePO4 Battery Voltage Charts (12V, 24V & 48V) – Footprint Hero

Here are LiFePO4 battery voltage charts showing state of charge primarily based on voltage for 12V, 24V and 48V batteries – as well as 3.2V LiFePO4 cells.

Note: These charts are all for a single battery at 0A. Also, lithium battery most lithium iron phosphate batteries follow these voltage curves, however not all. Consult the manual of your LFP battery for its specific discharge curve and voltage parameters.

12V LiFePO4 Battery Voltage Chart

12V 100Ah LiFePO4 batteries are at the moment a few of the most popular for off-grid solar power programs. They’re an ideal improve from 12V lead acid batteries. They’re fully charged at 14.6 volts. Fully discharged at 10 volts.6 volts and fully discharged at 10 volts. They’re made by connecting 4 3.2V LiFePO4 cells in sequence.

24V LiFePO4 Battery Voltage Chart

24V lithium iron phosphate batteries are one other fashionable choice for solar energy projects. You possibly can both buy off-the-shelf 24V batteries or buy 12V batteries. Connect them in series to make a 24V battery bank. They’re totally charged at 29.2 volts. Fully discharged at 20 volts.2 volts and fully discharged at 20 volts. They are made by connecting eight 3.2V LiFePO4 cells in series.

48V LiFePO4 Battery Voltage Chart

48V isn’t as popular of a voltage for photo voltaic programs, particularly for small-scale initiatives. They’re totally charged at 58.Four volts. Fully discharged at forty volts.4 volts and absolutely discharged at forty volts. They are made by connecting sixteen 3.2V LiFePO4 cells in sequence.

3.2V LiFePO4 Cell Voltage Chart

Individual LiFePO4 cells have a nominal voltage of 3.2 volts. They’re absolutely charged at 3.Sixty five volts. Fully discharged at 2.5 volts.Sixty five volts and fully discharged at 2.5 volts.

You should buy individual LiFePO4 cells online, though they’re harder to seek out than 12/24/48V LiFePO4 batteries. They’re finest used for making your own lithium batteries. You’ll be able to connect cells in collection and parallel to make LFP batteries with your desired voltage and capability combinations.

Three Ways to Check LiFePO4 Battery Capacity

1. Measure Battery Voltage with a Multimeter

Pros: Moderately accurate

Cons: Must disconnect all loads and chargers and let battery rest

Battery voltage modifications relying on charge and discharge charges. Plus, LiFePO4 batteries have a relatively flat discharge curve from round 99% to 20% capability. Because of these elements, it can be exhausting to estimate their state of charge from voltage alone.

To get an even somewhat correct estimate based on voltage, you first need to disconnect any loads and chargers from the battery. (Don’t neglect to disconnect your photo voltaic panels out of your charge controller first! If you enjoyed this short article and you would such as to obtain additional details pertaining to rechargeable battery (https://writeablog.net/birchsusan27/how-to-bill-a-lithium-polymer-battery-in-a-right-means) kindly go to our own internet site. Let the battery rest for a short while – I usually wait 15 minutes -. Then measure its voltage with a multimeter.

Compare your measurement to the fitting voltage curve above, or the state of charge chart in your battery manual. Use it to get a tough estimate of your battery’s remaining capacity.

For example, I just lately purchased the Ampere Time 12V 100Ah LiFePO4 Deep Cycle Battery. When it arrived, I pulled it out of the field and instantly measured its voltage with a multimeter. I received 13.23 volts.

I then compared this quantity to the 12V LiFePO4 state of charge chart above, as properly as the one within the battery manual.

Based on the charts, I’d estimate my battery’s state of charge was someplace around 80%.

I like this method greatest for estimating the state of charge of an LFP battery I’ve just obtained. The battery is already at rest. Not linked to anything. I discover it too inconvenient to disconnect every little thing once the battery is in use.

DIY lithium battery builders will even measure the voltage of used (and new) battery cells – resembling LFP cells and 18650 lithium batteries – to see that are good and which are duds.

2. Use a Battery Monitor

Pros: Most accurate, handy

Cons: Good battery displays are costly

One of the best ways to track battery capacity is to connect an excellent battery monitor – such because the Victron SmartShunt or Victron BMV-712.

Battery monitors monitor the quantity of amp hours consumed to precisely estimate the state of cost. They also show useful system specs corresponding to battery voltage and current. Some join through Bluetooth to your phone so you possibly can examine your LiFePO4 battery’s capacity in a cellular app.

3. Use a Solar Charge Controller

Pros: Convenient

Cons: Very inaccurate

You could also be considering:

“My solar charge controller already measures battery voltage. I can just use it to verify battery capacity.”

But!

This voltage reading is usually very inaccurate. It suffers from all of the issues mentioned above, plus it’s executed whereas the battery is related to hundreds and chargers.

For instance, recall that after i checked my battery’s voltage with a multimeter at the battery terminals, I acquired a voltage studying of 13.23 volts. That correlates to a roughly 80% state of cost.

But after i linked my battery to a solar charge controller, the controller measured 13.0 volts. That correlates to a roughly 30% state of cost – a difference of 50%!

After all, voltage drops underneath load. And a charge controller is a load. If I have been to attach a photo voltaic panel and begin photo voltaic charging the battery, voltage would change once more.

Checking battery capability this way is convenient. But it’s so inaccurate as to be almost useless. I generally use this voltage studying simply to ensure my battery isn’t close to being below or over voltage.

You should purchase a battery voltage sensor, such as the Renogy Battery Voltage Sensor or Victron Smart Battery Sense which work with some of their respective brand’s MPPT cost controllers. A voltage sensor gives the controller a extra accurate voltage studying, particularly in solar energy systems with long wire runs.

LiFePO4 battery pack Voltage FAQ

Note: The caveat to all the following solutions is that they apply to most LiFePO4 batteries. Consult your battery’s manual for its specific charging parameters.

What is the voltage of a totally charged 12V LiFePO4 battery?

A completely charged 12V LiFePO4 battery can have a charging voltage of round 14.6 volts and a resting voltage of around 13.6 volts.

How a lot are you able to discharge a LiFePO4 battery?

Many LiFePO4 batteries can discharge 100% of their rated capability each time with no ailing effects.

However, many manufacturers advocate discharging only 80% to maximise battery life. The truth is, some manufacturers state the cycle life of their batteries primarily based on 80% DOD.

For comparison, lead acid batteries can solely discharge 50% of their rated capacity. So a 12V 100Ah LFP battery has as a lot usable capability as a 12V 200Ah lead acid battery.

What’s the low-voltage cutoff of a 12V LiFePO4 battery?

The low-voltage cutoff of most 12V LiFePO4 batteries is around 10 volts. The BMS detects when the battery voltage falls under 10 volts. Disconnects the battery to stop over discharge.

Low-voltage cutoff can be called low-voltage disconnect, which you’ll generally see abbreviated LVD.

Once a battery enters low-voltage disconnect, it needs to be “woken up.” Consult with your battery’s manual for instructions on how to do that.

What’s the float voltage of a 12V LiFePO4 battery?

LiFePO4 batteries don’t have to be float charged as a result of they don’t leak cost the best way lead acid batteries do.

If you possibly can, disable float charging on your cost controller or battery charger. When you can’t, forestall the battery from getting into float charge by setting the float voltage to that beneficial within the battery handbook – usually 13.6 volts ± 0.2 volts.