We remind you that if you are interested in charging stations with lithium iron phosphate batteries (batteries), then a large assortment of models is presented in the profile section of the catalog. If you need a LiFePO4 battery for a UPS, then you can follow this link. And if you need a charger that will safely replenish the capacity of such a battery, then here you go.

Why is a lithium iron phosphate battery better?

LiFePO4 technology is one of the most advanced lithium batteries on the market. The main advantages of lithium iron phosphate batteries include the following:

  • Increased working resource. As a rule, LiFePO4 outperforms competitors by a margin in terms of the number of charge-discharge cycles without loss of working capacity.
  • High safety and environmental friendliness. The LiFePO4 composition is characterized by increased thermal and chemical stability, and does not contain potentially harmful substances - cadmium, lead or cobalt.
  • Ready for high loads. Lithium iron phosphate batteries perform well in tandem with powerful consumer devices.
  • Wide operating temperature range. LiFePO4 batteries are better adapted to difficult weather conditions, even working in cold weather.
  • All the advantages of lithium batteries, namely the absence of memory effect, minimal self-discharge, readiness for deep discharges (90% or more) and quick replenishment of battery capacity compared to any car batteries, for example, AGM.
Today, LiFePO4 is often used in portable charging stations.

What is the difference between LiFePO4 and Li-Ion?

LiFePO4 and Li-Ion are related solutions, as both types of batteries contain lithium. But they differ in their composition, which, among other things, creates a difference in performance properties. So iron-phosphate models can be considered a more progressive solution with additional advantages, namely:

  • Large number of charge-discharge cycles. On average, iron phosphate is 2 times better in durability than lithium-ion batteries. Typically, LiFePO4 are designed for a conditional 3000 or 4000 cycles, compared to 1500 or 2000 for top versions of Li-Ion.
  • Security. Lithium iron phosphate copes well with rising temperatures, does not emit harmful fumes and oxygen, and generally prevents various types of force majeure better than Li-Ion. The latter can overheat, and to prevent this from happening, protective systems with special controllers are needed.
  • Increased operational stability, including at low temperatures. Any lithium battery a priori does not like frost. Thus, Li-Ion discharges faster at minus values, and voltage readings can noticeably sag. LiFePO4 generally has higher overall operating stability and a wider temperature range, so they perform better under high loads (powering powerful devices) and adverse weather conditions (heat or frost).
  • Environmentally friendly. Lithium iron phosphate batteries do not contain cadmium and cobalt, which require proper disposal and are a negative factor for the environment. But the composition of Li-Ion batteries is less “green” in this regard.
Important advantages of LiFePO4 include environmental friendliness, durability and a wide operating temperature range.

Lithium-ion batteries also have an advantage over iron-phosphate batteries. Thus, with the same capacity, they are more compact and lighter, since they have a higher energy density. Even when purchasing charging stations, versions with Li-Ion will cost less than LiFePO4. The relative novelty of iron phosphate technology is probably to blame, since in general the cost of lithium-ion batteries is even higher.

You can read more about the differences between power lithium batteries in our profile material “Li-Ion or LiFePO4: Which is better for a charging station and UPS?”

Popular charging stations with LiFePO4 battery

Can LiFePO4 be charged with a car charger?

It is not recommended to replenish the capacity of an iron phosphate battery with a conventional car jump starter. At a minimum, this is fraught with a decrease in battery life and a drop in performance, and at a maximum - breakdown.

Auto-charging compatible with LiFePO4 has a profile operating mode.

Today there are car chargers on sale that provide a special mode for LiFePO4. It is these devices that should be used in tandem with these batteries. They will ensure stable voltage and power readings during power supply and completely stop the energy supply when reaching 100%. They can also be supplemented with various protective systems.

If there is no profile mode for iron-phosphate batteries, then in theory it is permissible to use car charging, which is characterized by the following parameters:

  • provides operating voltage up to 14.6 V;
  • allows you to disable desulfation or leveling mode (it is important to ensure that these options are not automatic);
  • before switching to maintenance charging there is no conditioning stage with an operating voltage of about 14 V;
  • plus, as soon as the charging process using this device is completed, you need to immediately disconnect the LiFePO4 battery.
Popular chargers for LiFePO4 batteries

How long does a lithium iron phosphate battery last?

The average working life for LiFePO4 is 3500 charge-discharge cycles without loss of capacity. Moreover, depending on the specific battery, this indicator can range from 2000 to several tens of thousands of cycles. In practice, degradation, that is, a noticeable loss of capacity, occurs after 7–10 years of operation. But much depends on the specifics of the application, compliance with storage and charging recommendations.

LiFePO4 is more expensive than a lead-acid (SLA) battery, but is many times more durable.

Iron phosphate batteries are approximately 7 to 10 times more durable than lead-acid batteries, and lithium-ion batteries are at least 2 times more durable.

What voltage should I use to charge a LiFePO4 battery?

For a lithium iron phosphate battery, the optimal “voltage” is 3.6 V per cell(but not more than 4.2 V). A standard 12-volt LiFePO4 has groups of four such elements, which means that it is recommended to charge it at a voltage of 14.2 to 14.6 V (3.6 V x 4 = 14.4 V). Whereas for 24-volt the range 28.4 – 29.2 V is suitable.

It is also important to consider that for LiFePO4 the charging process must include 2 main phases - constant power and constant voltage. So, at first, at one amperage, the volts gradually rise and then remain at the optimal level. And the power slowly drops to 2 A as you approach the end of the charging cycle.

You don’t really need the information described above if the charger you use provides a mode for LiFePO4 or if you have a UPS that “can” charge iron-phosphate batteries.

What is the self-discharge of LiFePO4?

The self-discharge rate of lithium iron phosphate batteries is the lowest compared to analogues. The indicators are very individual, that is, they depend on the specific battery. In general , the maximum self-discharge when stored at room temperature for LiFePO4 should not exceed 3% per month. In practice, manufacturers even provide such an indicator, so to speak, “in reserve,” and individual units discharge even more slowly when idle - by 3–5% per year.

To what voltage can LiFePO4 be discharged?

Lithium iron phosphate technology is notable for supporting high battery discharge rates without compromising reliability. Thus, it is LiFePO4 that can be operated down to the lowest voltage levels compared to analogues (lithium-ion and especially lead-acid batteries).

LiFePO4 slowly loses voltage, the differences at 100% and 25% are minimal

The acceptable minimum voltage is usually in the range of 2.2 to 2.8 V per cell. Accordingly, for 12-volt batteries of standard assemblies (with 4 batteries in a group), we obtain a maximum discharge of approximately 10 V.

It is worth considering that the minimum operating voltage is usually indicated in the instructions for a specific LiFePO4 battery. Plus, most modern models implement a BMS (Battery Management System) protective system, which will forcefully turn off the battery when a critical discharge depth is reached. In this case, the minimum working direction can be verified experimentally. In the future, it is better not to reach the maximum discharge in order to extend the overall working life of the battery.

How to store LiFePO4 battery?

Basic recommendations for storing lithium iron phosphate batteries are provided by manufacturers in their user manuals. It is the information in the instructions that you need to focus on first.

General storage recommendations are:

  • charge the battery to 100% or reach a voltage of 14.4 V. For short breaks in operation (up to several months), a full charge for the battery is not necessary - a range from 50 to 80% is sufficient. Partial battery capacity will not have a detrimental effect, unlike the simplest lead-acid analogues;
  • disconnect the device from the charger and consumers;
  • the optimal storage temperature is from 0 to 40 degrees Celsius, and for a long period (over 3 months) - closer to room values (about 20 °C);
  • for a short period of time (usually up to 30 days), a lithium iron phosphate battery can be left even in the cold (unless a different temperature range is declared by the manufacturer);
  • If possible, find a shaded, dry and well-ventilated place for the battery and protect the device from mechanical influences;
  • During long periods of downtime, it is recommended to periodically check the LiFePO4 charge level and maintain it above 50%.

Do you need a balancer for LiFePO4?

When purchasing ready-made batteries, the issue of having balancers, that is, devices for equalizing the voltage in battery cells during charging, is hardly relevant. Manufacturers know when they are needed and which ones. The situation is different with self-assemblies. Thus, balancers are necessary if the total capacity of the battery assembled independently exceeds 40 Ah. But for batteries up to 40 Ah, the balancing task is usually handled well by the BMS (Battery Management System) protective system.

For LiFePO4, it is recommended to use only passive balancers. These devices stop charging those battery cells that have reached the optimal voltage (usually 3.6 V) and simply remove excess energy as heat. Passive balancers work correctly with the BMS board and do not have a negative impact on the working life of the battery.

This is what balancers look like in LiFePO4 batteries with a BMS system.

But active equalizers - those that “know how” to distribute energy between cells - from those already charged to those still in the process, are not recommended for LiFePO4. They can reduce the overall resource and work incorrectly in tandem with the BMS.

Can LiFePO4 be inverted?

In theory, operation of a lithium iron phosphate battery is possible in any position. There is no acid that can spill out like lead batteries. And the liquid electrolyte in LiFePO4 is reliably protected inside sealed cells.

In any case, we recommend that you first read the instructions. Manufacturers often still prohibit turning over. This may be due to the specifics of heat removal (air exchange is disrupted if the battery is positioned differently), the layout of cells or other working elements, or simply the manufacturer’s desire to play it safe. Thus, attempts to overturn fairly heavy batteries may cause shocks or other undesirable mechanical impacts.

Is it possible to charge LiFePO4 in the cold?

In most cases, lithium iron phosphate batteries cannot be charged in sub-zero temperatures. It is permissible to replenish the battery capacity in the cold if there are built-in heating systems (low-power heaters), which allow the batteries to reach positive temperature values.

Many LiFePO4 batteries are ready to work effectively in cold weather, but charging is a little more complicated.

Even if the manufacturer allows charging in cold weather (say, at -5 or even -10 degrees Celsius), then this option is only advisable for emergency cases. In most situations, it is better to move the LiFePO4 battery into a warm place and then feed it with energy. It will also be much faster, because a safe charging process in cold weather requires amperage limits (and this greatly increases the overall time spent). So, for example, at temperatures below 0 °C the maximum charging power should be no more than 10% of the battery capacity (for example, for 80 Ah it is 8 A). And when the thermometer drops below -10 degrees, it is necessary to limit the power to 5% (in our example, 4 A).

How much does a LiFePO4 battery weigh?

The weight of a LiFePO4 battery directly depends on its capacity. The energy density for batteries of this technology usually ranges from 90 to 150 Wh/kg. Based on the average value, we will carry out approximate calculations for a 12 V battery per 100 Ah:

  • Let's convert Ah to Wh: 100 x 12 = 1200 Wh;
  • Let's calculate the weight taking into account the density of 120 W*h/kg - 1200 / 120 = 10 kg;
  • the final mass of the battery will be higher by about 1 or 2 kg, because the value of 10 kg does not take into account the battery case itself, additional electronics, etc. And in the case of charging stations, the final weight is even greater, because there are inverters, a cooling system and other elements.

Note that iron phosphate batteries are heavier than a lithium-ion battery of similar capacity, but much lighter than lead-acid and gel models.

Is it possible to connect a LiFePO4 battery to any UPS?

Not all uninterruptible power supplies are compatible with LiFePO4 batteries. In theory, you can connect such a battery to literally any UPS that supports external batteries. But due to the specific operation of the BMS system in a lithium-iron-phosphate battery, which maintains stable voltage readings, many uninterruptible power supply systems “do not recognize” its discharge, and therefore are not able to charge it.

If you want to use LiFePO4 with a UPS without any problems, then you need to choose uninterruptible power supplies that support charging these batteries and/or additionally clarify the fact of compatibility before purchasing.

Popular UPSs with support for charging LiFePO4 batteries