China leading LiPo battery manufacturer
- Powerful design and manufacturing ability
- 15 years experienced LiPo R&D team including battery expert
- Tens of thousands of cell and battery pack solutions
- High quality guaranteed
- Fast and prompt delivery
- Quick and professional support 24/7.
Understanding LiPo battery
What is lithium polymer battery?
Lithium polymer battery is rechargeable lithium ion battery with pouch shape and soft aluminium foil plastic film package.According to original definition for lithium polymer battery, it is using solid or Gel electrolyte and soft external aluminum foil film. However, most of polymer batteries in the world now refers to pouch cell, a lithium ion battery which uses soft square package.
- Name:Lithium polymer battery is also named lithium ion polymer battery,LiPo battery,Li-Poly battery,Li-Polymer battery.
- Basic structure: it is consist of mainly cathode,anode,separator, electrolyte.aluminum laminated film.
- Cathode structure: LiCoO2(Lithium cobalt oxide), conductive material,PVDF(adhesive), aluminum foil current collector.
- Anode structure: Graphite, conductive material,PVDF(adhesive), Copper foil current collector.
- Working principle : When the LiPo battery is charging, the Li ion move from cathode(positive) to anode(negative) where many caves are there in the graphite material, the ions entered the all the caves, then the battery is fully charged. When the battery is discharging, the Li ion move from graphite caves in the anode(negative) to cathode(positive) ,the ions left the all the caves, then the battery is fully discharged.
Parameters of lithium polymer battery
To understand and use Lithium polymer battery better, we must know clearly about below parameters.
- Nominal Voltage: The stable operating voltage,during the full discharge and charge time of Lithium polymer battery, there is a stable 3.7 v voltage in the discharge charge curve, that is the nominal voltage for LiPo battery. This parameter is important for a rechargeable battery cell, with a higher value, less of cells will be needed to reach a suitable battery pack voltage, smaller size and less weight can be achieved.For example, to make a 3.6V battery, we need 3 pieces 1.2V NiCH battery cell while only one lithium polymer battery cell is enough to make it, this makes LiPo battery much more attractive when engineers look for battery solutions.
- Charging voltage: This is the output voltage required for charging a lithium polymer battery, the value is 4.2 v.
- Charging cut off voltage: This is the protective setting to avoid over charging, it’s 4.25 v. It’s not allowed to charge the lithium polymer battery up to higher than 4.25 v. otherwise, it may cause danger and accident. The charging cut off function is always included in LiPo battery PCM, when the battery voltage rise up to 4.25V, this function will be activated and the circuit will be cut off.
- Nominal capacity: It’s the power that a battery can drain, let’s put it this way, if a LiPo battery discharge with a constant current of 1 A for 2 hours before it runs out of energy and cut off, then we can say the battery capacity is 2 Ah(1 A*2 Hours), its the calculation result of multiply of the discharge current and lasting time.
- Discharging cut off voltage : Voltage at which the battery stop discharging. This is a value set by lithium ion battery protection IC to protect the lithium polymer battery from over discharging, for LiPo battery cell it’s always 2.75 v or 3.0 v. This voltage is a design that each lithium battery protection circuit must have, it protects the battery during discharging, otherwise, over discharging can damage the battery.
- C rate: C rate is the result of current divided by battery capacity. Let’s take an example, If a 200mAh LiPo battery is discharging @ 2000mA, then we can say that it’s discharge c rate is 10C(2000mA/200mAh).Compared to it’s capacity, the bigger the current is, the higher the C rate is.
- Cycle life: We discharge the LiPo battery to cut off voltage, then we charge it @0.2C under room temperature 25C till it reaches 4.2V, and then we discharge it to 3.0V @0.2C, and keep it stay and wait for 5 minutes,this is called one cycle, then we repeat this process again and again, till the capacity become 80% of original value. The total cycle times we did before the battery capacity changed to 80% is the battery cycle life. Lithium polymer battery is 500 times.This is different from lifespan that we experience in daily life, but they both means similar things about a lipo battery life.
Advantages of Lithium polymer battery
As the most popular rechargeable lithium battery in market, Lithium polymer battery has many unique advantages, especially because it can be made into different shapes according design needs, this is deadly attractive for many industries such as the field of consumer electronics,smart devices, wearable devices. This feature is a key success factor for lipo battery,but it is absolutely not enough, it’s high voltage, low weight and other more features made it together.
- High voltage.
- High energy density.
- Flexibility on shapes.
- Light weight
- Maintain free
- No memory effect
- Low self discharge rate
- Environmental friendly
- Great high drain discharge performance
- Long cycle life
LiPo battery assembly and parts
Lithium polymer Battery cell
A bare lithium polymer battery cell is the basic unit of a lithium polymer battery pack.It has ability to operate discharging and recharging, but it has no protection circuit. Most time it will be added with a PCM to work, or the applications will themselves have protection built in the PCBA, otherwise it’s dangerous to use only the battery cell, because the possible over charging, over discharging, short circuit and over current can occur battery damage and injery accidents.
PCM for lithium polymer battery
PCM is the protection circuit module for rechargeable lithium polymer batteries.It includes four protections for:Over charge, over discharge , short circuit,over current.We use Japanese seiko IC on the PCM to offer high level protection for our lithium batteries.This is a strong external safety guaranty.Different PCM will be designed to fit the custom lipo battery packs according to different requirements.
NTC is Negative Temperature Coefficient, it is a popular thermometer sensor part used by many lithium polymer battery packs for temperature protection. NTC is important to sense the battery temperature and protect the lipo battery from too high temperature. 10k NTC is the typical one for 3.7v rechargeable lithium battery packs.We can add this part whenever clients requires it.
Battery connector is the accessory for connecting battery with devices PCBA or battery charger. By connecting way, there are Wire to wire type,Wire to Board type,Board to Board type. By brands and manufacturers, there are JST, Molex, HRS,ACES, JVT, JAE, HR,AMP, OUPIN, HIROSE, TYKO,DELPHI,KET and more.By wires amount, there are 2 pin, 3 pin, 4 pin, 5 pin, 6 pin and even more pins. We can choose different battery connectors to install on the lipo battery pack according to different requirements of customer’s projects.
About LiPo battery transport
LiPo battery is rechargeable lithium battery which is listed as dangerous goods for airway and sea way transport. Because fire accidents caused by transporting lithium ion batteries happened now and then, transport companies especially airlines and airports in all over the world released more and more strict regulations and limits to manage safe transporting of lithium ion batteries.With our professional service based on highly reliable battery quality management, as an experienced rechargeable lithium battery manufacturer and exporter, we have kept a good record of no accident in the past 15 years.
PD has enough experience to arrange transport to countries all over the world, with our transport partners, we can transport the lithium ion battery packs and lithium polymer battery through international express and airway transporting service suppliers such as UPS,DHL,FEDEX,TNT,etc.Our customers counted on us to arrange transport for the lithium batteries they ordered.
Lithium polymer battery package
We can design and use different packages to ship the lipo batteries according to transport company requirements. Sometimes we use custom made individual white boxes for each battery before we put them into bigger cartons. Sometimes, we use plastic battery trays and pack them tightly according to related dimension and weight standards.Cartons will be attached with caution labels.
Certificates for lithium polymer battery
Why and which certificates are always needed?
To get access to markets of different countries, lithium polymer battery products are always required to prepare some certificates and get them ready. In China, 3C certificate is needed for electrical and electronics products, CE is the condition to enter EU market, For Korea market, it’s KC. Also for some specified industry,there are some new certificates are necessary.Many consumer electronics such as wearable devices and smart glass, mobile phones all require IEC62133,medical devices with battery power requires UL1624. And for safe transport, worldwide airports needs us to offer them UN38.3 or MSDS.
Can PD prepare certificates for customers?
PD can arrange samples testing by third-party labs and prepare lithium battery certificates mentioned above for customers.Even there is no stock of the battery cells, we can produce new samples for the certificates needs. So far, we have got CE, ROHS,UN38.3,IEC62133,KC,CB,REACH,UL,MSDS and so on.
FAQ on lithium polymer battery
Question 1: Do you manufacture only 3.7v LiPo battery?
Answer: We manufacture 3.7V Lithium polymer battery cells, meantime, different LiPo battery packs are also available for us. we have powerful battery assembly ability, Different types of configurations are not problem for us,such as 2S,3S,4S,6S,,7S,10S,13S, 2S2P,3S2P,3S3P and so on.
Question 2: How to order LiPo battery?
Answer: The process to order our LiPo battery is as below:
- Confirm battery voltage,dimentions,capacity,discharge current,operating temperature, application,assembly
- We offer you with battery solution with quotes
- Confirm datasheets and order
- We send you invoice for payment
- Start battery manufacturing.
- Battery get ready and be delivered to you.
Question 3: What kind of Guranty do you have for your lithium polymer battery?
Answer: We offer one year guranty for our lithium battery products, We can take responsibility to replace if the defects are caused by manufacturing after investigation.However, if the problem is caused by incorrect dispatch, wrong operating,abused use, then its beyond our responsibility.
Question 4: How long is your lead time for lithium polymer battery samples and mass production?
Answer: For battery samples, If we have the same or compatible LiPo battery cells available in stock, then the lead time is generally 4~7 days. If there is no stock, we need to take 2~3 weeks to produce it.
For mass production, it takes generally 30 days when there is no stock. If there is enough battery in stock, it takes about 1~2 weeks.
Question 5: Can you offer custom LiPo battery solution if we can not find what we need on your website?
Answer: Yes. We have our own tooling workshop to develop our own new models for custom lithium polymer battery. You just need to tell us the width,length,thickness ,capacity you want to have, discharge rate and work temperature, we can evaluate and make a complete LiPo battery solution for your confirmation, As soon as you agree, we can start to customize the custom battery for you.
Question 6: Do you offer datasheets/specifications for your lithium polymer batteries?
Answer: Yes. We will confirm with you on the main parameters of the LiPo battery, such as the dimensions, capacity, cables, connectors,discharge current. Then we will offer official battery datasheet for your approval.
Question 7: What's your MOQ for manufacturing the 3.7v LiPo battery?
Answer: If we have it in stock, you can order any quantity. If it’s out of stock, generally speaking you need to order 5k pcs to start production, however, to support your project, before mass production, we can support one or two small quantity production.
Question 8: Can you arrange battery shipment for us ?
Answer: Sure. We can transport our lithium batteries to you through UPS, FEDEX,DHL. You can choose door to door express, airport to airport, seaway. It takes generally 3~4 days to arrive EU customers by UPS, 5~8 days by FEDEX.
Contact us with your inquires(batterylipo.com)
Tell us what kind of LiPo battery you are looking for:
2-Capacity you hope to have
4-Work current of your device
5-Cables and connector