1. What is 3.2V LiFePo4 Lithium iron phosphate Battery? And included types on the market.
    Lithium iron phosphate (LFP) batteries use phosphate as the cathode material and a graphitic carbon electrode as the anode. LFP batteries have a long life cycle with good thermal stability and electrochemical performance.
What Are They Used For:
    LFP battery cells have a nominal voltage of 3.2 volts, so connecting four of them in series results in a 12.8-volt battery. This makes LFP batteries the most common type of lithium battery for replacing lead-acid deep-cycle batteries.
    It is a high-power lithium-ion rechargeable battery for energy storage, EV, electric tools, yacht, solar systems that uses lithium iron phosphate as the positive material. LFP Battery has excellent safety and cycle life performance advantages and is the most critical technical index of a power battery.
    LFP batteries typically have a life cycle rating of 2,000 cycles or more. Unlike lead-acid batteries, depth of discharge has a minimal impact on the lifespan of LFP batteries. Most LFP manufacturers rate their batteries at 80% depth of discharge, and some even allow 100% discharging without damaging the battery.
    For Energy Storage Battery, Lifepo4 Battery mainly involve these application: Telecom base ESS, Wind ESS, Solar storage, Back-up uninterrupted power station.

2. Why choose LiFePo4(Lithium iron phosphate) as solar ESS battery (Energy Storage System)?
    Solar energy is a fantastic way to get power anywhere the sun shines. It works great but only when the sun is out, so it’s critical to have the best battery possible for storing solar energy. LiFePO4 battery chemistry is one of the best options for solar ESS battery for a number of reasons.
1) Long Battery Life
    Battery life is where LiFePO4 batteries make up for the higher initial cost. A high-quality LiFePO4 like Dragonfly Energy is designed to last 3000-5000 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 energy storage system application making them good for many years.
2) 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 RV or marine capacities with constant movement and jostling, LiFePO4 batteries still hold up well. For a long time use ESS battery, free maintenance is important for end user.
3) Lightweight
    Compare with traditional Lead-Acid battery, 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 energy storage ratio.
4) 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 ESS 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. Lead-acid battery need longer time to charge it full than LFP battery. 
5) 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 detrimental to the environment. There are fewer gas emissions from them and no risk of acid spills. This is important as ESS battery (Energy Storage System Battery) for what’s one of main reason we use Solar power replace other energy resources like: oil, coal, for we want to protect our earth better.

3. The comparison between LiFePo4 battery (Deep cycle lithium battery) with Lead-acid battery for ESS battery (Energy Storage System Battery)?  
    As you might have gathered from the FAQ above, LiFePO4 have many features make it suitable work as solar power storage battery. It stands head and shoulders above traditional lead-acid batteries of all types, and we consider it the best lithium battery option for solar ESS battery.
Lead-Acid Batteries
    Lead-acid batteries are likely the most familiar type that can be used for storage. The vast majority of gas-powered passenger vehicles operate with a lead-acid battery to power the starter and other electrical components.
    The battery chemistry is tried and true, having been around for generations. It’s easy to find, and they tend to be less expensive than lithium options. There are many different types of lead-acid such as flooded, Gel, AGM, or crystal but they all perform similarly for storage.
    Here we compare in detail between Lead-acid battery with LiFePo4 battery (it have another name: Deep cycle lithium battery according to its features) to help your choice:
1) The cost. while lead-acid is less expensive upfront, there are many drawbacks to solar storage. Chief among these is their usable capacity; you can only discharge them to 50% before they suffer damage. They also last for many fewer life cycles than lithium batteries. Charge rates are also slower and they suffer damage when not fully recharged properly a common occurrence with solar energy systems. LiFePo4 battery have no memory effect, the capacity attenuation very slow, When capacity left 80%, lifepo4 battery have cycle life 3000-5000 times in the test. they last thousands of more cycles than lead-acid. LiFePO4 battery, have a more advanced chemical makeup. Though they’re generally more expensive upfront, lithium batteries have proven their worth over the years in both small applications like cameras and cell phones as well as in large appliances and vehicles. From long term consider, LiFePo4 battery will save cost for us. And save the work to replace new battery.
2) Application. LiFePo4 battery have higher energy density, for same weight and volume, lead-acid battery only have 1/3-1/5 energy of LiFePo4 battery. For example, if you need one battery for your electric boat, if you choose lead-acid battery, need arrange at least 3 times space to put it. For more weight of boat, you need design larger energy to guarantee its endurance. What is the advantage of LiFePo4 battery (Lithium iron phosphate battery) on EV and E boat applications.
3) Maintenance. Some of lead-acid battery need maintenance frequently, some just need a few maintenance.
    LiFePo4 are totally free maintenance. You can use it 10-15 years, if you don’t require too much power, even can work longer time. Save the work to replace new battery, that is one really trouble work, and will delay things.
    As you can see, except the upfront cost, LiFePo4 battery almost take all advantages than lead-acid battery. the positives of LiFePO4 batteries greatly outweigh the negatives. Their efficiency and consistent energy output make it a clear winner.

4. The Maintenance Precautions of Solar Power System battery (ESS Battery)?
What is Solar power system / ESS battery?
there are 4 major types of ESS battery for solar according to its application
-on grid solar, off grid solar, and hybrid solar power system.
1) On grid- solar farm
    It is solar power plant, also called “solar farm”. This is mega-watt huge solar power system works as a power plant to generate electricity to public or private use. Solar panels connect to DC- AC inverter and send electricity to the AC grid. In most cases, it doesn’t need any battery as energy storage since all solar energy is sent to grid.
2) On grid-net metering
    It is home or office size solar power system. On Grid-net metering system can save your electricity bills. AC loads are directly supplied by solar power instead of grid. When solar panel generate more electricity than demand of AC loads, those surplus solar energy will be sold back to grid.
3) Off grid
    This is independent stand-alone solar power system without connecting to AC grid. Our LWI high performance gel deep cycle solar battery can provide long service life for off-grid solar power solution. Off-Grid solar power system gives you completely self-sustainable solar energy anytime, anywhere.
4) Hybrid
    Hybrid solar power system combines the advantages of “On Grid net metering ” and “Off grid” system. AC loads are supplied by solar power directly, the surplus solar energy can be used to charge batteries or sell back to grid. The batteries are charged by AC grid in cloudy day and night. Battery can be used to supply AC loads in day or night whenever grid electricity rate is expensive. AC loads also secured by LWI high quality gel deep cycle batteries when grid is failure (blackout).
What is a good battery pack for solar power system ?
    After understanding 4 major types of solar power systems, let’s talking to battery pack. The battery pack means several batteries with parallel and series connection set up into an energy storage pack, which store solar energy from solar panel and provide electricity to loads via DC-AC inverter. Battery pack is core item in a solar power system as an energy storage.
    We should use long cycle life battery and good performance cells for solar power system.
    Obviously, battery in a solar power system is being charged in daytime by sun and discharged in cloudy day or night. Battery is acting as a solar energy storage device, it reserve solar power in sunny time and provide power in raining time or night. So solar battery is always being fully charged and deeply discharged. We should choose long cycle life battery for battery pack.
    Also,Good performance of cells at high temperature and high temperature resistance 
    can able to use safely without problems. It is also the key of choosing a good battery pack for solar power system.
How many battery should I have for my solar power system ?
    It depends on how much AC loads, which are usually home electric appliance and how long they will be powered by batteries. For example, if you have 1500W AC loads and need to be powered by batteries for 3 hours. The calculation is :
  1500W x 3 hours = 4500Wh, which means you need 4500Wh battery capacity If we use 12V 150Ah long cycle battery, The single battery capacity is 12V x 150Ah = 1800Wh 4500Wh / 1800Wh = 2.5, so we need at least 3 pcs battery to support AC loads.
    However, the solar inverter system for household use is usually 48V system, It means solar panel and battery pack should be 48V. Single battery is 12V, so we need a multiple number of 4 which make it into 48V system by series connection. In above case, we need to use 4 pcs 12V 150Ah batteries for the battery pack.
What should I consider before choosing battery pack ?
    There are several factors that should be taken into account when determining the total cost over the life of the battery.
    Battery Price: low price is always attractive, but if low price comes at the expense of quality and battery life, the need for frequent battery replacements could boost the cost over time.
    Battery Capacity: Capacity is important because it’s a measure of the amount of energy stored in the battery.
    Battery Voltage: The battery bank voltage must be considered to ensure it matches the system requirements. The battery bank voltage is often determined by the inverter specifications if installing a DC-to-AC system or by the voltage of the loads in a DC system.
    Battery Cycle Life: The most critical consideration is cycle life, which provides the number of discharge/charge cycles the battery can provide before capacity drops to a specified percentage of rated capacity. Batteries from different manufacturers may have the same capacity and energy content and be similar in weight. But design, materials, process and quality influence how long the battery will cycle.

5. What is our Warranty time and detail Warranty Policy for Lithium ion battery and LiFePo4 (lithium iron phosphate) battery? 
The service life of Lithium ion 18650, 21700, 26650 battery is 2 years or 500-800 times cycle. 
The service life of Lithium ion prismatic battery is 3-5 years or 2000 times cycle. 
The service life of Lithium iron phosphate prismatic battery for electric vehicles application is 8-10 years or 2000-4000 times cycle. 
The service life of Lithium iron phosphate prismatic battery for energy storage application is 10-15 years or 3000-5000 times cycle.

According to this, Our warranty time is differ from battery types and applications:
    For Lithium ion and LiFePo4 cell, we supply one year warranty, make sure its voltage, internal resistance and capacity in promised range. Supply compensation or return for qualified one.
    For Lithium ion battery pack, we supply one year warranty. If have cells broken in warranty time, we supply replace new one. If BMS not work normally, we supply replace BMS, parts and technology support for maintenance. 
    For LiFePo4 battery pack of EV application, supply three years warranty. If cells or BMS not normally in warranty time, we supply replace new one and technology support for maintenance. 
    For LiFePo4 ESS (Energy storage system) battery module, we supply five years warranty for new developed ESS battery module to let our customer be assured for our quality. And supply three years warranty for proven ESS battery module.

6. As dangerous products, What is the shipment ways you can choice for Lithium Batteries? 
    From fast to slow delivery time, there are 4 channels for Lithium battery shipment: 
1) By UPS or DHL express service to door, the fastest way, need 5-10 days, to door but don’t include Tax and custom fee, customer need pay it himself.
2) By Air to door, this shipment is not cheap than by express to door service, need 10 days around. but it is DDP service, customer no need pay Tax and custom fee. Above two ways are suitable for sample or urgent orders. 
3) By sea to door or by train to door, this is cheapest door to door service, need 40-45 working days. The cost just 1/3 of UPS or DHL with DDP service.  
4) By sea to port, customer need arrange clearance and picking up goods for this shipment way, also the cheapest. It is suitable for batch order or full container shipment. 
  For shipment way 1) 2) 3), no need any special documents for clearance in China, can ship via HongKong. For shipment way 4), need MSDS, UN38.3 and dangerous goods package certificate to book container.