You can revive a sleeping 12V LiFePO4 battery, which voltage is around 5V. To revive that, connect your battery with another similar battery and wait until it wakes up your sleeping battery. And then charge it normally.
What Is the Riving Process Of LiFePO4 Battery?
Riving a LiFePO4 battery means waking it up from sleep mode. If your LiFePO4 battery discharges even lower than the cutoff voltage point, the battery management system will send it to sleep mode to protect your battery from irreversible damage.
If your battery is near the cutoff voltage, you can wake it up again using some tricks. This waking-up process is called battery reviving. However, some batteries go beyond the scope of reviving.
There are many ways you can try it. But I will show you two of the most reliable methods of reviving your LiFePO4 battery. One uses a power supply, and the other uses another battery with similar specs.
What’s The Success Rate of Battery Reviving?
You might be wondering whether you can revive any dead batteries. The answer is, No. I’m afraid some batteries are dead.
You can only revive those sleeping LiFePO4 batteries whose voltage is somewhere near the cutoff voltage points. For example, if you have a 12V sleeping LiFePO4 battery, and its voltage is about 5V, the chance is 100% that you can revive it.
But if you have a battery whose voltage is as low as 0.5V or 0.4V, you will not be able to revive it no matter what you do. So, it depends on your battery condition.
Processes of Riving LiFePO4 Battery
As I have mentioned earlier, there are two reliable ways I will show to revive a sleeping LiFePO4 battery. So, let’s check them out.
Method 1: Reviving LiFePO4 Battery Using Another Similar Battery
Before you follow this procedure, I strongly urge you to refer to your battery’s manual. If there is any conflict, avoid the process.
Now let’s move to my first method. You will need the following equipment for that.
|A Sleeping LiFePO4 Battery||Another LiFePO4 battery With the Same Nominal Voltage|
|A Multimeter||Jumper Cables|
Here’s the step-by-step process of reviving your LiFePO4 battery.
Step 1: Remove All the Loads
First, you must disconnect all the loads and charges from your battery. Then let the battery rest for 30 minutes at room temperature.
Now check the open circuit voltage with a multimeter. Some LiFePO4 batteries have a self-waking feature that can wake the battery after removing all loads. But if your battery is around 5 volts, it’s in sleep mode and needs to be woken up.
Step 2: Connect Your Sleeping Battery with Another LiFePO4 Battery
Connect your sleeping LiFePO4 battery with another battery in parallel mode.
Both batteries have to be in the same voltage. For example, if your sleeping battery’s nominal volt is 12V, the second battery should be between 12 and 14.6 volts.
The following table shows the voltage level of the second battery based on the first battery’s voltage
|First Battery Voltage||Second Battery Voltage|
|3.2V||3.2V to 3.65V|
|12V||12V to 14.6V|
|24V||24V to 29.2V|
|48V||48V to 58.4V|
For a parallel circuit, connect the positive terminal to the positive and the negative terminal to the negative with jumper cables.
In most cases, both batteries need to be of a similar type. However, some manufacturers allow other kinds of batteries as well. Refer to your manual for that.
Step 3: Wait A Few Moments.
Now it’s time to buckle up and wait for a few minutes. While doing that, the second battery works on waking up your sleeping battery.
Usually, you have to wait up to 3 to 5 minutes. Check your battery manual for any specified waiting time, and follow that if there is any.
However, the waiting time can be different for different brands. For example, Ampere Time recommends waiting 1 to 3 minutes, whereas Battle Born recommends a few minutes to an hour.
Step 4: Check Your Battery Voltage
It’s time to remove the jumper cables and check your sleeping battery’s voltage. If the 12V battery voltage is around 11 to 12 volts, it means- your battery has successfully woken up.
But if the voltage is still lower, just keep connected the two batteries for longer. Check the voltage level of your second battery. Make sure it’s within the acceptable voltage range.
If it doesn’t wake up in the worst-case scenario, you might have to contact the manufacturer or scrap your battery. The possibility is that your battery has become completely dead.
Step 5: Normally Charge Your Battery
The final step involves charging the waken battery. Fully charge your Lifep4 battery until it reaches 14.6 volts.
Do not worry if you see an under-voltage warning. It will go away once it’s fully charged.
Method 2: Reviving LiFePO4 Battery Using a Power Supply
A group of scientists found that you can revive a sleeping LiFePO4 battery using a power supply. But it only works if your battery is not taking charge because of the low voltage. You will need a 30V and 10A power supply for this process.
So, here’s the step-by-step process.
- Firstly, set your power supply to 13.8 volts and turn amps all the way up several times.
- Then, attach the power supply leads to your LiFePO4 battery.
- Now, turn the amps up to 1% of your battery capacity. If your battery is 100 amp, set it to 1 amp.
- After that, let the power supply run for about 1 hour. Your battery’s voltage should rise to around 12V.
- Finally, charge your LiFePO4 battery with its charger.
Remember that none of the above two processes gives you absolute certainty that your battery will wake up. None of them is 100% accurate. It mostly depends on your battery condition.
If your battery is sleeping for too long and the voltage tends to zero, the chances are minimum that it will wake up.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.