FAQ

First of all, it is necessary to ensure the storage environment around the LiFePO4 battery. The battery storage environment should be dry and ventilated, regardless of the season. In addition, ensure that the SOC of the LiFePO4 battery is 50% or above, which is the best storage capacity, but be careful not to store at full SOC.

Summer Storage:
In summer, due to the relatively high temperature, the self-discharge rate of LiFePO4 batteries will be relatively higher, about 3-4% per month. Although the LiFePO4 battery is a high-temperature battery, it is best not to place it in a place that is too hot. An indoor room that is almost the same as the room temperature is the best choice.

Winter Storage:
Winter is the season when most people do battery storage. Because many people use LiFePO4 batteries as camping batteries, they will not be of much use in winter. During winter, the temperature is relatively low, and in some areas it may reach -20°C. Since the battery is actually a chemical reaction, in winter, the self-discharge rate of the battery will be relatively low, about 2~3% per month. However, it should be noted that when storing batteries in winter, it is best to ensure that the battery storage temperature is higher than room temperature, especially in an environment of -20°C. Too low temperature is not a good thing for batteries. Again, it should be stored indoors. More information can be found in: LiFePO4 Battery Winterize.

It should be noted that when LiFePO4 batteries are stored, all loads need to be disconnected. That is, the positive and negative electrodes are completely reserved. It is not recommended to store the BMS/inverter/charger, etc. connected to the battery, as it will speed up the consumption of the battery. If you have to do this, be sure to use a battery protector to prevent battery abnormalities. Of course, don’t forget to re-balance the LiFePO4 battery when you want to re-enable it after battery storage.

The following is the storage time and the corresponding temperature recommendation, of course, this is not absolute, just a value worthy of reference, I hope it can help you.

Storage for about 1 month: 0°C ~ 40°C

Storage for 3 months (one season): -10°C ~ 35°C

Long-term storage (about 6 months): -10°C ~ 25°C

It is worth mentioning that the LiFePO4 battery needs to be taken out for a complete cycle after about half a year of storage to ensure the performance of the battery.

Lithium-ion batteries can boast different kinds of chemistry based on the application. Regarding solar battery storage, LiFePO4 (lithium iron phosphate) has a battery chemistry that stands out above both lead-acid and other lithium batteries.

LiFePO4 batteries are widely considered the safest type of lithium battery, and they last for a decade or longer. They also offer flexible charging and deeper discharge cycles without damage.

Long Battery Life
Lithium iron phosphate batteries have a lifecycle two to four times longer than lithium-ion. A high-quality LiFePO4 like Infinisolar is designed to last 3000-6000 cycles of deep discharging and still retain 80% of its original capacity. This is critical for a solar system because the batteries are used every single night and recharged every day.

In reality, the battery life cycles are even higher as most discharges are not full. 10,000-15,000 cycles are common for LiFePO4 in a solar application making them good for many years.

Little to No Maintenance
Because our LiFePO4 batteries come with a built-in battery management system, they’re highly efficient. This also means that they require little to no maintenance. Even if you’re using your battery for RVing or marine capacities with constant movement and jostling, LiFePO4 batteries still hold up well.

Lightweight
LiFePO4 batteries also come with considerable weight savings. They generally weigh about one-third to one-half of what a lead-acid battery weighs. This means you can ramp up your battery bank since it takes two or three LiFePO4 batteries to equal the weight of one lead-acid battery. They also have more usable capacity, which maximizes their weight to power ratio.

Fast Charging Time
LiFePO4 batteries offer lower resistance, and they don’t require a float charging cycle. So they charge much faster than lead-acid batteries. When you’re relying on solar power, a battery that recharges faster is significant. If there are only a few hours of pure sunlight per day where you are, a shorter charge time is gold.

Environmentally Friendly
LiFePO4 batteries are non-toxic and recyclable. Many of us want to use solar energy for its environmental benefits, so it only makes sense to utilize solar battery storage that’s not detrimental to the environment. There are fewer gas emissions from them and no risk of acid spills.

When weighing the options for solar battery storage, there’s really no argument: LiFePO4 batteries are the best option.

Factors that affect the life of LiFePO4 battery cell

1, Charge and discharge
Slow charging can extend the life of the battery compared with fast charging. It is best to use the charger with the stop charging function(such as anti-overcharge cut-off, negative voltage difference (-dV) cut-off and anti-overheating cut-off). To avoid lithium iron phosphate batteries due to overcharging and shorten the life of use.

We should avoid over-discharging the LiFePo4 cell to a very low voltage. The depth of discharge is the main factor affecting the life of lithium iron phosphate batteries. The higher the depth of discharge, the shorter the life of the LiFePo4 cell. In other words, simply reduce the depth of discharge, you can significantly extend the life of the LiFePo4 battery.

Not mixed use. Different capacity, different chemical structure or different charging levels, as well as a mix of old and new batteries, will make discharge too much. Which will constitute a reverse charge.

Assuming that a long time without charging lithium iron phosphate batteries, will reduce its life. LiFePo4 battery needs to keep electronic activity for a long time to reach its ideal life expectancy.

2, Operating environment
If we using the LiFePO4 battery cell at high temperatures for a long time, the electrode activity will decay. Then shortening the use of life. So try to adhere to the appropriate operating temperature. Which is a good way to extend the life of lithium iron phosphate batteries.

Prevent the accumulation of dust inside the pack, and maintain the battery inside the power supply on time. The depth of discharge is the main factor affecting the life of lithium iron phosphate batteries. The higher the depth of discharge, the shorter the life of the LiFePo4 cell. In other words, simply reduce the depth of discharge, you can significantly extend the life of the LiFePo4 battery.

LiFePo4 batteries require long periods of electron activity to reach their ideal life span.

The life span of LiFePo4 battery is followed by the number of times with the charge and decay. The general lithium iron phosphate battery charge is 3000-5000 times.

Lithium iron phosphate battery maintenance strategy

1, The temperature should be moderate
Temperature should not be too low and too high. If the operating temperature is higher than 35 ° C, the battery power will continue to reduce. The battery power supply time will not be as long as usual. If charging at such temperatures, the damage to the battery will be even greater. Even if storing in a hotter environment, it will inevitably cause corresponding damage to the quality of the battery. Therefore, trying to maintain a moderately favorable operating temperature is a good way to extend the battery’s life.

If used in a low-temperature environment, that is, below 4 ° C, it will reduce the life of LiFePo4 battery. Should avoid charging at 0 ° C or below.

2, The frequency of use should be in place
To play the maximum effectiveness of lithium iron phosphate batteries, you need to use it often. So that the electrons within the lithium battery is always in a state of flow. If you do not often use lithium, please be sure to remember to complete a monthly charge cycle. Do a power calibration, that is, deep discharge deep charge once.

3, Avoid mixing with metal objects
Do not mix the battery cell with metal objects. Avoid metal objects cause a short circuit and damage the battery or even causing danger.

4, The surrounding environment should be suitable
Lithium iron phosphate batteries should be in a clean, dry, ventilated environment. Should avoid contact with corrosive substances, away from fire and heat sources.

Lithium iron phosphate battery life we can generally get from its specifications on its theoretical life. But the actual use of life is generally a certain distance from the theoretical life. Good use habits can make the battery cell life extension.

Only in this way, lithium iron phosphate batteries can be properly maintained and remain healthy.

In the energy industry, peak shaving refers to leveling out peaks in electricity use by industrial and commercial power consumers. Power consumption peaks are important in terms of grid stability, but they also affect power procurement costs: In many countries, electricity prices for large-scale consumers are set with reference to their maximum peak-load. The reason is simple: the grid load and the necessary amount of power production need to be designed to accommodate these peak loads.

Comparision Between Load Shifting and Peak Shaving

With peak shaving, a consumer reduces power consumption (“load shedding”) quickly and for a short period of time to avoid a spike in consumption. This is either possible by temporarily scaling down production, activating an on-site power generation system, or relying on a battery. 

In contrast, load shifting refers to a short-term reduction in electricity consumption followed by an increase in production at a later time when power prices or grid demand is lower. Dedicated generators or electricity storage facilities owned by the power consumer can be used to bridge high-price or high-load phases, but play less of a role if production will eventually catch up again.

Peak loads and grid usage fees

Peak loads are not popular with grid operators; they must design the grid based on the maximum amount of power that will be needed. Nevertheless, everyday operation at many industrial companies – such as powering up or increasing a production process – can cause fluctuating loads on the grid. It is possible to reliably detect the source of a sudden load increase by monitoring power consumption. Depending on the grid operator, these peaks are used to calculate grid usage fees assessed to certain power consumers. The following example illustrates how these additional grid fees are calculated for a medium-sized company in Germany.

Calculation example

A company has a constant load of 4,000 kW throughout the year without peak loads. The company pays a fixed annual grid fee, which is assessed per kilowatt. In this example, this is 50 € per kW: 4,000 kW x 50 € = 200,000 € per year in grid charges. A special production order causes an exceptional peak load of an additional 500 kW, which lasts for just 30 minutes. The grid fee increases immediately, with additional costs of 25,000 € based on 4,500 kW of annual consumption. This is just to cover grid usage and does not include the cost of electricity utilized by the company.

1.1 State-Of-Charge (SOC)
State of charge can be defined as the state of available electrical energy in a battery, usually expressed as a percentage. Because the available electrical energy varies with charge and discharge current, temperature and aging phenomena, the definition of state of charge is also divided into two types: Absolute State-Of-Charge; ASOC) and relative state of charge (Relative State-of-Charge; ASOC) State-Of-Charge; RSOC). Usually the relative state of charge is in the range of 0% – 100%, while the battery is 100% when fully charged and 0% when fully discharged. The absolute state of charge is a reference value calculated from the designed fixed capacity value when the battery is manufactured. The absolute state of charge of a brand new fully charged battery is 100%; an aged battery, even fully charged, will never reach 100% under different charge and discharge conditions.

1.2 Max Charging Voltage
Maximum charge voltage and battery chemistry are related to characteristics. The charging voltage of lithium batteries is usually 4.2V and 4.35V, and the voltage value will be different if the cathode and anode materials are different.

1.3 Fully Charged
When the difference between the battery voltage and the highest charging voltage is less than 100mV, and the charging current is reduced to C/10, the battery can be regarded as fully charged. Battery characteristics vary, as do full charge conditions.

1.4 Mini Discharging Voltage
The minimum discharge voltage can be defined by the cut-off discharge voltage, which is usually the voltage at which the state of charge is 0%. This voltage value is not a fixed value, but varies with load, temperature, degree of aging, or others.

1.5 Fully Discharge
When the battery voltage is less than or equal to the minimum discharge voltage, it can be called full discharge.

1.6 Charge-discharge rate (C-Rate)
The charge-discharge rate is a representation of the charge-discharge current relative to the battery capacity. For example, after an hour of discharge at 1C, ideally, the battery will be fully discharged. Different charge and discharge rates will result in different usable capacities. Generally, the higher the charge-discharge rate, the smaller the usable capacity.

1.7 Cycle life
The number of cycles is the number of times a battery has undergone a complete charge and discharge, which can be estimated from the actual discharge capacity and the design capacity. Every time the accumulated discharge capacity is equal to the design capacity, the cycle number is once. Usually after 500 charge-discharge cycles, the capacity of a fully charged battery will drop by about 10% to 20%.

1.8 Self-Discharge
The self-discharge of all batteries increases with temperature. Self-discharge is basically not a manufacturing flaw, but a characteristic of the battery itself. However, improper handling during the manufacturing process can also lead to an increase in self-discharge. Typically, the self-discharge rate doubles for every 10°C increase in battery temperature. The monthly self-discharge of lithium-ion batteries is about 1~2%, while the monthly self-discharge of various nickel-based batteries is 10~15%.

2.1 Introduction to the function of the fuel gauge
Battery management can be considered a part of power management. In battery management, the fuel gauge is responsible for estimating battery capacity. Its basic function is to monitor voltage, charge/discharge current and battery temperature, and to estimate battery state of charge (SOC) and battery full charge capacity (FCC). There are two typical methods for estimating the state of charge of a battery: the open circuit voltage method (OCV) and the coulometric method. Another method is the dynamic voltage algorithm designed by RICHTEK.

2.2 Open circuit voltage method
Using the open-circuit voltage method of the fuel gauge, its realization method is relatively easy, and can be obtained by looking up the table of the open-circuit voltage corresponding to the state of charge. The open circuit voltage is assumed to be the battery terminal voltage when the battery is resting for approximately more than 30 minutes.

Under different load, temperature, and battery aging conditions, the battery voltage curve will also be different. Therefore, a fixed open-circuit voltmeter cannot fully represent the state of charge; the state of charge cannot be estimated by looking up the table alone. In other words, if the state of charge is estimated only by looking up the table, the error will be large.

2.3 Coulomb measurement
The principle of operation of the coulometric method is the connection of a sense resistor in the charge/discharge path of the battery. The ADC measures the voltage across the sense resistor and converts it to the current value of the battery being charged or discharged. A real-time counter (RTC) provides integration of this current value over time to know how many coulombs are flowing.

2.4 Dynamic Voltage Algorithm Fuel Gauge
The Dynamic Voltage Algorithm Fuel Gauge calculates the state of charge of a Li-Ion battery based solely on the battery voltage. This method is based on the difference between the battery voltage and the battery’s open circuit voltage to estimate the increase or decrease in the state of charge. The information of dynamic voltage can effectively simulate the behavior of lithium battery, and then determine the state of charge SOC (%), but this method cannot estimate the battery capacity value (mAh).

It is calculated by using an iterative algorithm to calculate the state of charge for each increase or decrease based on the dynamic difference between the battery voltage and the open circuit voltage to estimate the state of charge. In contrast to coulombic fuel gauge solutions, dynamic voltage algorithm fuel gauges do not accumulate errors over time and current. Coulometric fuel gauges often suffer from inaccurate state-of-charge estimation due to current sensing errors and battery self-discharge. Even though the current-sensing error is very small, the coulomb counter continues to accumulate errors that can only be eliminated when fully charged or fully discharged.

The Dynamic Voltage Algorithm Fuel Gauge estimates the battery’s state of charge from voltage information only; since it is not estimated from the battery’s current information, no error is accumulated. To improve the accuracy of the state of charge, the dynamic voltage algorithm needs to use an actual device to adjust the parameters of an optimized algorithm from the actual battery voltage curve under the condition of full charge and full discharge.

Fast-growing and more affordable than conventional power sources like fossil fuels is Solar energy. Residential solar installations in the US are constantly breaking growth records. The cost of solar technology has considerably dropped in recent years as a result of increased use.

Solar energy is quite appealing as more individuals look for ways to lower their carbon impact (and their electricity expenses). However, solar power has numerous other advantages for individual homeowners, the economy, and the environment in addition to the obvious advantage of generating clean, renewable energy.

To decide if solar energy is the best option for you and your family, learn about its advantages.

1.Source Of Renewable Energy

The fact that solar energy is a renewable energy source is one of its key advantages. In contrast to other energy production methods like fossil fuels or nuclear power, renewable energy may be used without destroying priceless natural resources.

2.Friendly To The Environment

Solar energy is ecologically good since it is clean and renewable. It doesn’t release any pollutants into the atmosphere, including greenhouse gases.

solar panels can also lessen or even remove your dependence on your local electricity grid and safeguard your family against blackouts.

Sustainability is the primary driver of solar adoption, and it’s getting more and more affordable for households who want to contribute to environmental protection.

3.Lowered Electricity Costs

Utilizing solar energy to produce electricity can drastically lower your monthly electric bills and eventually help you recoup your initial investment in a home solar power system. Depending on how much electricity you consume and how much power your solar array can produce, it can even eliminate your electricity bill. 

4.Net Metering And Tax Credits

Homeowners can benefit from federal, state, and local tax credits in addition to utility cost reductions. These solar incentives include a 30% tax credit to help you pay the costs of installing and maintaining a domestic solar power system as well as your original investment in one.

The government is continuously thinking of methods to make solar energy even more cost-effective in the long run as meeting net-zero carbon emission objectives becomes an urgent issue.

Another initiative that encourages the conversion to solar electricity is net metering. With net metering programs, you can resell any extra electricity to your utility provider if you have a solar power system that is connected to the grid. The grid is also available anytime you need it, such as at night or during really bad weather, if you use more electricity than you produce.

5.Increased Value Of Homes

Installing solar panels on your house might raise its value, particularly if the array has already been paid for. You’ll not only save money on your electricity costs while residing in your house thanks to this, but you’ll also gain more equity if and when you decide to sell.

Forbes claims that “every dollar a solar panel saves you on your electrical bills increases the value of your home by $20.”

6.Power During Disasters and Outages

Off-grid solar energy can power vital gadgets and appliances during a power outage. As more regions grow vulnerable to harsh weather conditions and natural disasters like hurricanes or floods, access to off-grid power is turning into a requirement. Aging infrastructure, extreme weather, and growing demand can all cause grid power for days or weeks outages.

You may build a backup system, such as the 2000W power station Solar Generator, to give a whole home backup power solution when the next blackout occurs even if you don’t already have a totally off-grid solar power system.

7.Getting More Affordable (With ARapid And High ROI)

Recent price reductions have made renewable energy technology substantially more accessible to the average customer. Although there is still a large upfront commitment, prices are dropping. In between five and ten years, depending on consumption, government incentives, and finance, many consumers recover their initial costs.

8.Low Costs Of Maintenance

Since solar panel systems are self-sufficient in generating electricity from sunlight alone once installed, they typically require little maintenance over the course of their lifespan. Furthermore, a lot of manufacturers provide multi-year warranties that include parts, labor, and repairs in the event of a problem.

9.Home Automation Integration

Smart technology is changing how we manage home temperature, keep an eye on who is at the door, and even control the brightness of the lights and the air conditioner – and you can do it all remotely using a smartphone.

Modern solar energy innovations are keeping up with these technologies, and you can create a whole ecosystem of smart home ecosystem that you can operate from an app on your phone. Say good-bye to antiquated power sources and hello to energy efficiency in the future.

10.Suitable For Various Applications And Remote Locations

In isolated areas where access to conventional types of electricity may be few or unstable, harnessing the power of the sun is excellent. Almost every situation may be used to create power using solar technology, which is incredibly adaptable.

Adding a solar battery bank to your solar installation can have several benefits. You’ll be able to survive power outages by running your home on just solar power, and you can use the energy stored in your batteries to power your home during peak usage times when electricity from the utility is more expensive.

We’re not quite yet at the point where battery storage can pay off its financial cost with savings on your electric bill, but you can’t put a price on the peace of mind you feel knowing that your solar panels and batteries will be enough to keep you warm and safe if (or when, if you live in PG&E territory in California) the power goes out.

If you’ve decided to get a home solar battery, but have yet to determine how much energy storage you’ll need, let’s dive in to figuring out how much battery capacity you’ll need.

How many batteries do you need to run a house?

The key question to ask when choosing a solar battery bank is “how many batteries do I need?” The answer to that question depends on what you want to power, how long you think you might need the backup, and the type of batteries you choose.

What You Can Power With A Solar Battery Bank

If the power goes out, what do you want your life to be like? If you need to have full power, you’ll be looking for what’s called a “whole home battery system,” which can keep your air conditioned, your food frozen, and your clothes dryer running, but not all at the same time (more on that below).

If you can get along with keeping your food cold and the lights on, you can choose to power “critical loads” only. That would keep the A/C and electric stove off, but run refrigeration, wi-fi, lights, and outlets to charge devices.

Calculating Your Needs

If you’re looking to power your whole home during an extended outage, you’ll need to know your average usage per day. You can look at your electric bill or login to your utility company’s website to find out how many kilowatt-hours you use in a month or year.

If you’re looking at monthly usage, be sure to choose the month in which your usage is highest. You don’t want to lose power for three days in July and go without A/C because you didn’t choose enough battery capacity.

For our example of PG&E territory in California, it looks like usage for the average residential customer has two annual peak months, July and December, which makes sense, because that’s when you’ll be needing HVAC running. Those peaks hover around 675 kWh in a month, or about 22 kWh per day.

How to Balance Batteries in Series – Charge Each Battery Individually for Greater Performance & Lifespan

Linking 12 Volt batteries in series is an easy way to create higher voltage 24V, 36V and 48V battery systems. Before linking batteries in series however it is helpful to first charge each battery individually. This is called balancing batteries in series, also known as voltage matching.

Balancing batteries in series has two big benefits:

1.The total capacity of the system will be higher. This means more runtime for your golf cart, trolling motor, solar battery bank, or whatever you are powering.

2.The lifespan of each battery will be longer since the stress of running to empty is evening shared by all batteries instead of a single battery.

Lithium Iron Phosphate (LiFePO4) batteries have a long lifespan (typically 5 – 15 years), and twice the usable power of traditional batteries. To ensure you are getting the maximum performance and lifespan we recommend all customers balance their batteries before linking them in series.

Here’s directions on how you can balance your batteries in series:

1.Use a 12V Lithtech Lithium or LiFePO4 compatible charger to charge each battery individually (all Dakota Lithium batteries 50Ah and larger come with a free 12V 10Amp LiFePO4 charger). The LED light on the battery will be red when charging and will turn green when the battery is fully charged. You only need to do this once before you set up your system. In the future you can charge the entire system with the higher voltage charger.

2.Once all batteries are fully charged you can install them in series to create a higher voltage system (24V, 36V, 48V, etc.). The batteries in the system are now balanced.

3.When charging in the future it may be more convenient to use a higher voltage Lithtech Lithium or LiFePO4 compatible charger to charge the entire set when linked (for example, a 36V battery set can be charged with a 36V LiFePO4 battery charger).

4.Do NOT use a 24V, 36V, or 48V charger to charge a single 12V battery pack. The higher voltage charger is only for charging the full set / series system at a high voltage. It is too much power for charging a single 12V battery pack.

Performance impact / benefit of balancing lithium batteries in series:

1.Increases the run time of what you are powering by 10 – 20%

2.Increases the lifespan of the batteries by 1 to 3 years depending on use.

Engineering explanation (why balancing batteries in series helps improve performance)

• Federal DOT shipping regulations require that Dakota Lithium batteries (and all lithium or LiFePO4 batteries) are shipped at a low state of charge (<20%). This means each battery arrives near empty and with a slightly different charge and slightly different voltage.

• Charging each 12V battery individually ensures that each battery is full and at the same voltage before the batteries are linked in series. This is called “matching the voltage / voltage matching”, or “balancing the batteries” and increases the total runtime and lifespan.

• If the batteries are linked in series when near empty and then charged with a higher voltage charger the battery charger will read the system as “full” once one of the batteries in the set is fully charged, even if one or two other batteries in the set are only 75% full.

• If one of the batteries in the system is at 75% capacity the system will only perform with 75% of capacity, even if the other batteries are at 100%.

• If one of the batteries in the system is at 75% capacity the system while the others are at 100% then every time the system runs to empty the single battery will be discharged to zero, and experience higher stress, resulting in a shorter lifespan.

• By charging each battery individually before linking in series to create a higher voltage system you have made sure that all batteries are 100% full and that your system is performing at its best.

When should I balance my batteries in series in the future?

• Balance your batteries after long periods of storage (>3 months), or if you see a significant performance drop.

• Balancing your batteries once a year will extend the battery lifespan.

Earth Day is a time to reflect on the impact that our actions have on the environment and to take steps towards a more sustainable future. As a manufacturer of lithium-ion batteries, our company recognizes the importance of clean energy and is committed to making a positive contribution to the world.

Lithium-ion batteries are a crucial component in the transition towards renewable energy. They are used in everything from electric cars to grid storage systems, enabling us to harness the power of wind and solar energy in a more efficient way. By manufacturing high-quality lithium-ion batteries, our company is helping to accelerate the adoption of clean energy and reduce our reliance on fossil fuels.

On this Earth Day, we are proud to reaffirm our commitment to sustainability and clean energy. We will continue to invest in research and development, and work towards improving the efficiency and sustainability of our products. We believe that by working together, we can create a cleaner, more sustainable future for all.