Here you can find a library of blogs, videos, and FAQs all about charging your lithium battery

plus a complete LiFePO4 Charging Instructions technical guide.

Everything You Need To Know About Charging Lithium Iron Phosphate Batteries

Have you recently purchased your first lithium battery and are unsure where to start when it comes to charging? Learn everything you need to know about charging your lithium battery - from charging conditions to battery storage - in this blog.

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You've Got Questions. RELiON Has Answers.

Frequently Asked Questions

Can I use my existing lead-acid battery charger (Wet, AGM or Gel) to charge RELiON lithium iron phosphate batteries?
We encourage new Lithium battery owners to use a charger that has a Lithium specific charge profile for LiFePO4 batteries. These are easy to find since most chargers on the market today have a lithium charge profile, and LiFePO4 is the predominant Lithium battery chemistry in the marketplace. However, some customers would like to continue using their existing Lead-Acid charger if possible. Although many existing lead-acid chargers will still charge our Lithium battery, it is generally discouraged to do this. The risk is the lead-acid chargers may wind up in fault code condition at some point, despite the Lithium battery probably having received a full recharge. The problem is that the conditions incurred during the fault codes can also cause issues and/or damage to other system electronics, and even the charger itself. Therefore, we strongly recommend you use a Lithium battery charger. If this recommendation is neglected then it is best to choose AGM, Gel, sealed battery charge profiles to charge a Lithium battery.
Can I use my alternator to charge my lithium iron phosphate batteries?
RELiON batteries can be charged with most alternators. Depending on the quality of the alternator, it should work with LiFePO4 batteries. Low quality alternators with poor voltage regulation can cause the BMS to disconnect LiFePO4 batteries. If the BMS disconnects the batteries, the alternator could be damaged. To protect your LiFePO4 battery and alternator please be sure to use a compatible high-quality alternator or install a voltage regulator. Please contact RELiON technical support if you need assistance.
How long will it take to charge a lithium battery?
Lithium iron phosphate batteries can be charged in as fast as 1 hour. We recommend using a rate that charges our batteries in 2-5 hours. Please refer to the data sheet for your particular model, to find the recommended charge rates. All of our data sheets are available on our website within the product section.
How can I determine the state of charge (SOC) of my lithium iron phosphate battery?
The best way to determine the SOC of your battery is to use a battery indicator— a high-precision instrument that captures instantaneous and integrated data in real-time. We sell Mastervolt brand gauges for Legacy batteries, and InSight gauges for InSight batteries.
How strictly do I need to follow the recharging limits?
The short answer is “not very.” Our specs call for the batteries to be recharged to 14 to 14.6 volts for bulk charging, and to float the battery at 13.8 volts. If you recharge the battery below that range, you’ll have less than 100% charge in the battery - it will be at a partial state of charge. All that means is you’ll need to recharge it again sooner than you otherwise would. But you’re not harming the battery in any way by coming in lower than our recommended range - you’re only cutting into the capacity you’ll have from that charge. If you go over the 14.6 volt limit, our battery monitoring system - or BMS - will sense the over-voltage and disconnect from the battery. That’s it! The only thing that will happen is that the BMS will do what it is designed to do and protect your battery.
Are lithium batteries poorly affected by partial state of charge (PSOC)?
No! Drawing current from a lithium battery does not produce any harmful or undesirable byproducts. Charging and recharging simply moves lithium ions from one side of a membrane to another. Lithium batteries also have their peak performance when they spend their life at a partial state of charge. The ideal maximum charge for a lithium-ion battery is about 80-90%. This is much more practical in terms of the time and amperage necessary to recharge your battery, and it gives you a margin of error for when things don’t go as planned.
How deep can a lithium iron phosphate battery be discharged?
LiFePO4 batteries can be discharged up to 100% without risk of damage. Make sure you charge your battery immediately after discharge. We recommend discharging be limited to 80-90% depth of discharge (DOD) to avoid the BMS disconnecting the battery.
How does the rate of discharge effect capacity?
The rate of discharge for LiFePO4 batteries has virtually no effect on the delivered capacity. This is not the case with lead-acid batteries which have significantly reduced capacity of up to 50% as the rate of discharge increases.

Need More?

Review our technical LiFePO4 Charging Instructions guide and check out the videos below.

Lithium Charge Time vs. Lead-Acid

In this video, we cover the common question of how long it takes to charge your lithium battery. In addition, we'll touch on whether or not you can use your existing lead-acid charger for a lithium battery and how to go about doing so properly.

Depth of Discharge (DOD) and State of Charge (SOC)

In this Tech Tuesday, Simon discusses the depth of discharge, or DOD, state of charge, or SOC, and how it affects a lithium battery. In addition, we cover how the rate of discharge effects of lithium vs. lead-acid batteries.

Charging With Your Alternator

We often get asked if our lithium batteries can be charged with an alternator. In short, yes, they can be, but it is important to make sure you have a quality alternator for the best results. In this video, we'll provide all the details you need to know.

Voltage Parameters When Charging

RELiON lithium battery specifications call for our batteries to be recharged to 14 to 14.6 volts for bulk charging and to float the battery at 13.8 volts. Many customers ask how strictly they need to observe those limits. In this video, we answer this common question and discuss why.

Have Additional Questions?

Read through more of our FAQs or contact our team of dedicated LiFePO4 specialists!