What is a Lithium Polymer Battery? Explore Working, Prices, Benefits, Cons 

A lithium polymer battery, also known as LiPo lithium battery or Li polymer battery, is a rechargeable battery that uses solid polymer electrolyte instead of a completely liquid electrolyte found in traditional lithium-ion batteries. Unlike other types of rechargeable batteries, such as lithium-ion and lead-acid batteries, the LiPo lithium battery is extremely lightweight and can be customized into different shapes and sizes. 

With a nominal voltage of 3.7 volts that can reach 4.2 volts per cell when fully charged, lithium polymer batteries are widely used in tablets, smartphones, power banks, radio-controlled aircrafts, and drones. Although rare, they can also be used for storing solar energy in off-grid solar systems. 

Despite their higher energy density and compact design, LiPo lithium batteries require careful handling. Overcharging, puncturing, exposure to extreme heat, or ignoring the manufacturer’s safety guidelines can cause swelling, leakage, or even fire.

In this guide, we’ll explain how lithium polymer batteries work and how they’re made, share their advantages and disadvantages, outline safe handling practices, compare them with lithium-ion batteries, and explore their pricing in 2025.

TL;DR Summary Box: Are Lithium Polymer Batteries Safe?

When used with a LiPo-compatible charger and handled according to safety guidelines, lithium polymer batteries are safe to operate. They offer a good balance of energy density and weight. 

LiPo batteries can deliver high discharge currents. Hence, they’re suitable for devices that need quick bursts of power, such as drones, RC vehicles, and certain portable electronics. However, it’s important to note that Li polymer batteries are less thermally stable than other lithium batteries. Improper charging, puncturing, or overheating can lead to swelling or fire.

Here are the key topics which have been covered in detail in this blog:

Topic	Quick Takeaway
What is a lithium polymer battery?	A lithium polymer battery is a rechargeable battery that uses a gelled electrolyte.
Which is better, lithium-polymer or lithium-ion batteries?	LiPo lithium batteries are better suited for applications that require thin, lightweight, or custom-made batteries.  Standard Li-ion batteries are better for toughness, lower cost, and easier replacement.
What are the benefits of li polymer batteries?	They’re thin and lightweight, can be custom-shaped, use space efficiently in devices, and can deliver strong power bursts with low self-discharge.
What are the disadvantages of lithium polymer batteries?	They’re more sensitive to heat, puncture, and overcharge. Since these batteries can swell and be a fire hazard, they need careful charging and storage.
What are the uses of a LiPo lithium battery?	Phones, tablets, wearables, drones/RC, and power banks or compact devices
Do you need lithium batteries with on-grid rooftop solar systems?	No. On-grid solar systems use the grid for export and backup. Batteries are needed only for off-grid or hybrid solar systems.

What is a Lithium Polymer Battery?

A Li polymer battery is an advanced rechargeable battery that uses solid polymer electrolyte in place of liquid electrolyte that’s used in lithium-ion batteries. Many commercially available polymer batteries nowadays use gelled polymer instead of completely solid polymer. This hybrid LiPo battery with gelled polymer is known as a lithium-ion polymer battery. 

The polymer electrolyte allows lithium battery manufacturers to create batteries in various shapes and sizes while maintaining excellent energy storage capabilities. It means that, despite being compact, lithium polymer batteries store higher energy in a given volume than many other types of rechargeable batteries.

How is a Li Polymer Battery Made?

A lithium polymer battery is made of multiple components, carefully packed in loose pouches that offer these batteries their flexibility. 

Before we explain how a LiPo lithium battery is made, you must develop an understanding of all its main components: 

• Polymer electrolyte: This solid or gel-like material conducts lithium ions between electrodes.
• Cathode materials: Lithium cobalt oxide, lithium iron phosphate, or lithium manganese oxide.
• Anode composition: Graphite or silicon-based materials for lithium-ion storage.
• Separator layer: Polymer membrane preventing electrode contact while allowing ion flow.
• Flexible packaging: Aluminum pouches enable custom shapes and lightweight construction.

Now, let’s check out how these batteries are made:

• Step 1 – Planning the size and shape of the LiPo lithium battery: As strange as this might sound, it’s completely true in the case of lithium polymer batteries. They don’t have a standard size. Thus, the manufacturer determines the battery’s size, shape, and storage capacity based on the application for which the battery is being made.
• Step 2 – Preparing the cathode, which is the positive side of the battery: A special powder that stores energy is mixed with other materials to help the battery work better. This mixture is spread like a thin layer of paste on a sheet of aluminum foil and then dried.
• Step 3 – Preparing the anode, which is the negative side of the battery: Another type of powder, usually made from graphite, is prepared separately from the cathode. Instead of aluminium foil, the mixture of anode is spread on a sheet of copper foil, and then dried.
• Step 4 – Connection tabs between the anode and cathode are added: Small metal tabs are attached to both the positive and negative foils. 
• Step 5 – Battery layers are built: Thin plastic sheets called separators are placed between the positive and negative layers to prevent them from touching and short-circuiting. These layers are stacked on top of each other.
• Step 6 – Everything is placed in a flexible pouch: The stack of layers from step 5 is put into a soft but strong pouch made from aluminum and plastic. This pouch keeps the battery light and allows for different shapes.
• Step 7 – Moisture is completely removed: Before adding the electrolyte, the pouch is dried in special machines to remove moisture because water can damage the battery.
• Step 8 – Electrolyte is added: A special gel-like material is poured into the pouch. This material allows lithium ions to move between the two sides of the battery when it charges or discharges.
• Step 9 – The pouch is sealed: The pouch is sealed tightly so nothing can leak out, and no air or water can get in.
• Step 10 – The lithium polymer battery is tested: The battery is charged and discharged slowly for the first time in a controlled environment. This helps form a protective layer inside, allowing the battery to work safely and last longer.
• Step 11 – Removal of extra gas, if needed: Sometimes, a small amount of gas forms inside the battery during the first charge. The manufacturer removes this gas, and the pouch is resealed.
• Step 12 – Final testing and sorting before sale: Each LiPo lithium battery undergoes testing to ensure its power, safety, and quality. Good ones are packed for use.  

How Does a LiPo Lithium Battery Work?

A LiPo lithium battery has a positive side (cathode), a negative side (anode), and a thin plastic sheet between them soaked in a gel-like electrolyte that lets lithium ions move. The working begins as soon as voltage is created between the cathode and anode ends. 

Here’s a step-by-step guide on how a lithium polymer battery works:

• Step 1 – Voltage is created between the positive and negative sides: Because the two sides hold energy at different levels, there is already about 3.7 volts of potential difference in each cell even before it is used.
• Step 2 – Lithium ions move to power your device: When you turn a device on, lithium ions travel from the negative side of the battery to the positive side through the electrolyte. While lithium ions move inside the battery, electrons flow through the device from the negative side to the positive side. This flow of electrons creates electricity that powers the device. As the device charges, the battery depletes.
• Step 3 – The separator keeps the two sides from touching: The separator prevents a short circuit but still allows lithium ions to pass between the two sides during charging and discharging.
• Step 4 – The electrolyte acts as a highway for lithium ions: The gel material inside the separator helps lithium ions travel quickly between the positive and negative sides.
• Step 5 – Energy is released until the lithium ions reach the other side: As more ions move from the negative to the positive side, the battery’s stored energy decreases. Eventually, it needs to be recharged.

How to Charge Lithium Polymer Batteries Safely?

Use LiPo-compatible chargers with automatic cutoff and temperature monitoring in order to safely charge these batteries. You can also use fire-resistant charging bags during charging for added safety. It’s always recommended to charge the battery to 4.2 volts per cell. Since this is the maximum, do not exceed it as it might cause the battery to overheat.

Here’s a step-by-step guide on how you can charge a lithium-ion polymer battery safely:

• Step 1 – Confirm the battery details to determine the correct voltage: Always check for cell count. It’s displayed as 1S, 2S, 3S, and so on. 1S means there’s one cell in the battery pack, 2S means there are two cells connected in series, and so on. Suppose your battery pack is marked 2S; the maximum nominal voltage for this pack will be 8.4 volts (4.2 x 2).
• Step 2 – Use a LiPo-compatible charger only: The charger must have a LiPo mode and support balance charging. Never use NiMH/NiCd or trickle modes for charging a lithium polymer battery.
• Step 3 – Connect the battery to the charger: First, plug in the small balance connector, then the main leads. The charger now sees each cell and confirms the S count.
• Step 4 – Press start to begin charging in Constant Current (CC): The charger feeds a steady current. On screen, you’ll see the voltage slowly climb. Inside the cell, lithium ions move toward the negative side to store energy.
• Step 5 – The charger keeps an eye on each cell and starts balancing: If one cell charges faster, the charger gently bleeds it down to keep all cells at a similar level. This keeps the pack even and safe.
• Step 6 – The battery pack reaches the voltage limit (about 4.20 V per cell): The charger switches automatically to Constant Voltage (CV). Voltage now stays fixed, and current begins to drop on its own.
• Step 7 – Disconnect the battery and let it rest for a few minutes: The voltage settles slightly, and the pack is ready to use.

Safety Considerations to Follow When Charging LiPo Lithium Batteries

When charging a lithium-ion polymer battery, always put the battery on a non-flammable surface. A LiPo-safe bag or fireproof container is recommended.

Here are all the safety precautions you must follow when charging a lithium polymer battery:

• Set a safe charge current: A good default is 1C. Go higher only if the manufacturer allows it.
• Connect the leads correctly: For multi-cell packs, plug in the balance lead first, then the main power leads, matching polarity. For 1S packs, use the main leads only.
• Check the battery for damage: Look for swelling, tears, punctures, leaks, odd smell, or hot spots. If you see any of these, do not charge the battery.
• Stay nearby and monitor: During charging, the pack may get slightly warm. However, it should not get hot. If you see swelling, smell chemicals, or readings jump around, stop the charge immediately and disconnect safely.
• Let the charger finish automatically: LiPo charging uses CC/CV and stops at about 4.20 V per cell when the current tapers. Do not top up or trickle a LiPo lithium battery.
• Follow temperature limits: Avoid charging below 0°C or above 45°C. Room temperature is best for safety and battery health.
• Use timer settings: Set maximum charging time limits to prevent overcharging.

What Are the Benefits of a LiPo Lithium Battery?

Lithium polymer batteries are flexible and compact. They can be customized into many shapes and sizes. Furthermore, they have a higher energy density and extended cycle life, which makes them suitable for many purposes. 

Let’s check out all the benefits of a lithium polymer battery in detail:

• They have a higher energy density: Compared with NiMH or lead-acid batteries, a LiPo polymer battery offers higher energy per kilogram. Therefore, devices run longer without adding bulk.
• They can be customized into different shapes and sizes: LiPo cells are made as soft pouches. Hence, manufacturers can build them in many shapes and thicknesses to fit tight spaces.
• They have a higher power delivery: Many LiPo cells can deliver strong bursts of current without damaging the battery or the device being charged. This is ideal for drones, RC gear, and performance electronics.
• They have a low discharge rate: Like other lithium-ion batteries, LiPo cells lose very little charge when sitting unused for weeks or months.
• They come in a wide capacity range: From tiny wearables to multi-amp-hour packs that can store electricity generated by solar panels, LiPo cells are available across many sizes to match different applications.
• They have an extended cycle life: Unlike lithium-ion batteries that can last for 500-1,000 charge cycles, lithium polymer batteries can last for 1,500-2,000 charge cycles. 

What Are the Disadvantages of Lithium Polymer Batteries?

Lithium polymer batteries can be a safety hazard and fire risk if you fail to follow the manufacturer’s instructions to charge and store these batteries. If overcharged or overheated, LiPo batteries can catch fire. 

Here are the disadvantages of a lithium polymer battery that you must know:

• They’re a fire risk if mishandled: Overcharging, puncturing, or overheating can result in a fire.
• The batteries can swell over time: Gas can form inside from side reactions. This may cause the pouch to swell. A swollen pack loses capacity and should not be charged at all.
• They are sensitive to over-discharge: Letting a cell drop below ~3 volts can cause permanent damage and safety risk.
• Mechanically delicate pouch: The soft pouch can be bent or punctured more easily than hard-cased cells. Hence, it needs physical protection.
• Temperature limits: While extreme cold reduces power and usable capacity, high heat accelerates aging.
• Quality variation across suppliers: Poor manufacturing can lead to imbalance, faster aging, or safety issues.
• Replacement can be tricky: Custom sizes are great for design, but make replacements harder to find later.

Lithium Polymer Battery Price in India in 2025

The cost of a lithium polymer battery in India can range from a few hundred rupees to lakhs of rupees based on the size of the battery pack and the manufacturer. For instance, a 500 mAh LiPo lithium battery can cost ~Rs. 120* and the high-end batteries used to store kilowatts of solar electricity can cost as much as Rs. 1.5 lakhs*. 

*Please note: The lithium polymer battery prices mentioned above are based on standard market estimates. They can significantly vary by brand, capacity (mAh/Wh/kWh), discharge rating (C-rating), cell grade, included protection/BMS, connectors/enclosure, warranty, certifications, seller, city, and market conditions, taxes (GST), import duty, shipping/handling, delivery, and installation. SolarSquare does not manufacture, sell, install, or endorse any brand. Always confirm the exact specification and what’s included (taxes, delivery, installation, and warranty) with authorized suppliers.

What Are the Applications/ Uses of a Li Polymer Battery?

Small and compact lithium polymer batteries can be used to charge smartphones, tablets, and power banks. The larger battery packs, which range in kilowatt-hours, can be used to store the solar electricity generated by solar panels. 

Let’s check out the multiple applications of a li polymer battery in detail:

• Smartphones & tablets: Thin, flat LiPo pouch cells fit tight spaces and keep devices slim.
• Wearables & hearables (smartwatches, fitness bands, and earphones): Custom shapes and small capacities make LiPo ideal for lightweight devices.
• Drones & RC aircraft: High C-rating LiPo lithium battery packs can supply big bursts of current for takeoff without adding to the weight.
• RC cars and boats: Strong, repeatable power delivery and compact packs suit high-draw motors.
• Power banks: Many small power banks use single-cell LiPo for simple, rechargeable 5-volt outputs.
• Ultra-thin laptops: When manufacturers need very slim batteries, LiPo pouches can replace cylindrical cans.
• Medical & fitness devices: Portable monitors like ECG machines benefit from these batteries as they’re lightweight and custom-designed.
• Solar energy systems: Although lithium-ion batteries are more commonly used for storing solar renewable energy in PV systems, LiPo batteries can also be used.

Which is Better, Li-ion or Lithium Polymer Batteries?

Although lithium polymer batteries have the highest voltage among all types of lithium batteries and they’re very flexible, lithium-ion batteries are more commonly used for storing solar energy in battery-based solar PV systems as they allow longer runtime and are comparatively cheaper. 

Both types have their advantages and disadvantages. Here’s a head-on comparison between the two types so you can choose the one that’s more suitable for you:

Feature	Lithium-ion Battery	Li Polymer Battery
What is it?	A rechargeable battery in a rigid metal case.	A rechargeable battery in a thin, flexible pouch.
Shape and size	Mostly available in standard sizes only.	Can be very thin Available in custom shapes
Fits best in	Laptops, power tools, e-bikes, and big packs.	Phones, tablets, drones, slim gadgets.
Space utilization	Round cans can waste space.	Flat packs use space very well.
Weight	Slightly heavier packaging.	Lighter packaging.
Power burst	Good, varies by model.	Great for short, strong bursts.
Toughness	The hard case resists bumps and punctures.	The pouch needs gentle handling These batteries can puff and swell
Safety if damaged	More forgiving to physical abuse.	More risky if punctured or overcharged.
Price and availability	Usually cheaper Easy to source and replace	Can cost more Custom sizes are harder to replace

Do You Require LiPo Batteries With On-Grid Solar Systems?

No battery is required with on-grid rooftop solar panel systems for homes, housing societies, or commercial complexes and industries. You need batteries only with off-grid and hybrid solar systems. 

A rooftop on-grid solar system offers the best ROI for homes and housing societies. The government also offers a subsidy under the PM Surya Ghar Muft Bijli Yojana for installing rooftop solar for housing societies and homes. However, if you’re installing commercial rooftop systems or off-grid solar systems, you won’t be eligible for the subsidy. 

It’s best to install on-grid rooftop solar systems when you have a reliable grid, since the government offers a subsidy, and no batteries are involved. Still not sure? Here’s a snapshot of the costs involved in installing an on-grid rooftop solar system at homes in a city like Nagpur, compared to the savings this system can generate over its 25-year lifespan. Have a look before making any decision:  

Solar System Size	Solar Panel Price in Nagpur With Subsidy (Starting Price – Indicative for Base Variant)*	Solar Savings in Nagpur in 25 Years*
2 kWp	~ Rs. 1.15 lakh	~ Rs. 11.05 lakh
3 kWp	~ Rs. 1.32 lakh	~ Rs. 16.58 lakh
4 kWp	~ Rs. 1.77 lakh	~ Rs. 22.11 lakh
5 kWp	~ Rs. 2.27 lakh	~ Rs. 34.43 lakh
10 kWp	~ Rs. 5.02 lakh	~ Rs. 68.86 lakh

*Please note: The above-mentioned solar plate price is indicative as of 11th August 2025 for the SolarSquare Blue 6ft variant. The final cost of installing an on-grid rooftop solar panel system at home depends on your DISCOM charges, product variant opted for, panel type, inverter type, mounting structure height, type of after-sales service, savings guarantee, roof height, etc. Prices are subject to change. Additionally, while calculating savings, we have considered the annual tariff escalation at 3% and the annual degradation at 1%. The actual final savings from solar panel installation depend on the types of solar panels you’ve installed and their efficiency, intensity of sunlight your rooftop receives, orientation of the panels and tilt angle, the pollution level and weather conditions in your city, the temperature, shadow on the roof, impact of dirt/dust, and how well you maintain your panels after installation.

So you see? Installing on-grid solar isn’t an expense in its true sense. It’s an investment that offers returns better than any other form of investment can ever offer. If you’re not from Nagpur but would like to get an estimate of solar savings in your city, use SolarSquare’s free rooftop solar calculator.

Conclusion

The main difference between a lithium polymer battery and a lithium-ion battery is that the former uses solid polymer (or gelled polymer) instead of the liquid electrolyte used by lithium-ion batteries. A Li polymer battery, also known as a LiPo polymer battery, is compact, lightweight, and has a low discharge rate. They can be customized into different shapes and sizes, making them super versatile.
However, if you’re planning to buy lithium batteries for solar energy systems, opt for lithium-ion batteries. And if you’re installing an on-grid solar system, you don’t need batteries at all. Book a free solar consultation with SolarSquare for any further details.

FAQs

Q1. Which is better, LiFePO4 or LiPo?

Ans. A LiFePO4 battery is safer, runs cooler, and usually lasts thousands of cycles, but it’s heavier and stores less energy. A LiPo lithium battery, on the other hand, is thinner, lighter, and can deliver big power bursts. However, it ages faster and needs more careful handling.

Q2. How long does a Li polymer battery last?

Ans. A lithium polymer battery, also known as a li polymer battery, can last for 1,500 to 2,000 cycles.

Q3. Are iPhone batteries Li polymer?

Ans. No. iPhones generally use lithium-ion batteries, not lithium polymer batteries.