LiPo 3S Battery 101: All About LiPo 3S Batteries

Lithium Polymer 3S batteries, also known as LiPo 3S batteries are lightweight and very powerful rechargeable lithium batteries. Lithium Polymer batteries feature electrolytes in the form of polymer gel with graphic anode and cathode in the form of a Lithium Cobalt Oxide (LiCoO2) or some similar material.

LiPo 3S batteries consist of 3 (three) LiPo cells connected in series, hence "3S". LiPo 3S batteries are commonly used in high-performance toys, drones, RC vehicles, and similar applications where high energy density is required, combined with high discharge currents.

Updated: November 14, 2024.

LiPo 3S Battery Voltage

LiPo 3S batteries consist of 3 (three) rechargeable lithium polymer cells connected in series - so-called 3S1P configuration. Each individual cell features a nominal voltage of 3.7 volts (rarely 3.6 volts), a maximum charging voltage of 4.2 volts, and a cutoff voltage of 2.7 - 3.0 volts (may slightly differ among the brands).

Note: some high-voltage LiPo batteries feature a nominal voltage of 3.8-3.9V per cell.

Thus, the 3S LiPo battery features a nominal voltage of 11.1 volts (rarely 10.8 volts), a maximum charging voltage of 12.6 volts, and a cutoff voltage of around 9 volts. High-voltage 3S LiPo batteries have slightly higher voltage and charging voltage should be adjusted as recommended by the battery manufacturer.

The nominal capacity of the 3S LiPo batteries varies from several hundred mAh to 5-10+ Ah - small 3S LiPo batteries are often used in small helicopters, drones, electric RC gliders, and similar applications, while large 3S LiPo batteries power large RC trucks and other RC vehicles. 

Discharge currents vary greatly and usually range from 25C to 120C+ currents.

For example, a 100C 5000 mAh 3S LiPo battery is able to provide 500 Amps, which, in theory, is enough to crank full-size cars.

Note: Lithium car battery jump starters are based on high-drain lithium rechargeable batteries, which are able to provide 50-100C+ currents.

Most popular LiPo 3S batteries feature discharge current in the 50-100C range. Such batteries can provide plenty of energy for RC applications like RC trucks, RC cars, RC planes, drones, and similar, but if required, they can also provide plenty of energy for shorter periods of time ensuring great acceleration, liftoff, and other required maneuvers.

The energy density of the 3S LiPo batteries varies from 120 to 250 Wh/kg, but it also depends on the discharge currents - LiPo batteries don't suffer from the capacity loss due to the increase in discharge current like lead-acid batteries do, but nonetheless, it is not the same to discharge the same battery at a rate of 1C or 100C.

Note: when the new 3S LiPo battery (or batteries) arrives, be sure to check the manual/Owner's Guide in order to get accustomed to your new battery - some battery models can be rather specific in terms of charging, discharging, storage, transport, etc.

One of the important features of the 3S and other LiPo batteries is that they feature two different cables/wires:

• discharging cables are thick and used ONLY for discharging. Depending on the intended use, battery size, average, and maximum discharge current, etc., 3S LiPo batteries usually come with Dean's T connector (T plug), XT30 plug, XT60 plug, EC5 plug, TR plug, etc.

Note: although it is good to avoid additional connections, if required, various adapters can help with mismatched plugs.

• charging cables are thinner and used for both charging and cell balancing. 3S LiPo batteries commonly use JST-XH(R) connectors and in combination with balance chargers, allow the user to both recharge the battery and to balance the individual cells, prolonging the operating lifetime of the battery.

Versatile and Reliable Haisito Smart Balance Charger (LiPo, Li-ion, Li-Fe, NiCd, NiMH) (Amazon link, opens in the new window)

When charging not just LiPo 3S batteries, but all LiPo batteries, never leave them unattended.

Although 3S LiPo batteries are capable of providing insanely strong currents, their charging currents should be kept in the 0.5-1.0C range or as recommended by the manufacturer.

Also, it is good practice to charge/discharge brand new 3S LiPo batteries few times at home, under controlled conditions by gradually increasing the Depth of Discharge (DoD%).

For example, charge/discharge the battery down to 25% DoD, then down to 50% DoD and then down to 75% DoD, after which the battery can be used freely.

Note: Some manufacturers claim that this is not required/necessary, but ...

Also, having a good fireproof and explosion-proof carry/storage LiPo battery bag can increase safety significantly.

Very popular, affordable, but tough and durable: Zeee Fireproof and Explosion-proof LiPo Battery Bag (Amazon affiliate link, opens in the new window)

Personally, even if You do have such bag(s), do not leave these batteries unattended when they are charging. These bags do increase safety, but Lithium Polymer batteries can burn/explode even without the oxygen present. And if the oxygen is present, fire can be really hot and spread further...

In the long run, it is good to have a high-quality balance LiPo battery charger that can increase safety and the LiPo's number of charging/discharging cycles which on average ranges from 100 to 300 cycles, sometimes even more.

How Long Does a 3S LiPo Battery Last?

A 3S LiPo battery's lifespan depends on usage, charging practices, and storage conditions. Typically, a 3S LiPo battery lasts between 200 to 300 charge cycles if maintained correctly.

Regular use and proper charging increase its lifespan, while high-stress conditions like frequent high-drain usage and overcharging reduce it.

To extend battery life, charge at a moderate rate, avoid full discharge, and keep the battery within safe temperature ranges.

Store the battery at a partial charge of around 50-60% if unused for long periods. With these practices, a 3S LiPo battery can perform well for about 1 to 2 years before a noticeable drop in capacity occurs.

How Can I Choose the Right 3S LiPo Battery for My Device?

To choose the right 3S LiPo battery for your device, focus on three main factors: voltage, capacity, and discharge rating. These elements determine whether the battery will perform safely and efficiently in your device.

• Voltage: A 3S LiPo battery has a nominal voltage of 11.1V (3.7V per cell). Ensure that your device is compatible with this voltage to avoid potential damage. Some devices may have a recommended voltage range, so confirm that 11.1V is within safe limits.
• Capacity (mAh): Battery capacity, measured in milliamp hours (mAh), indicates how long the battery can power your device. Higher capacity means longer runtime but also adds weight and size. Choose a capacity that balances runtime and the physical space available in your device. For instance, a 3000mAh battery will provide more runtime than a 1500mAh battery, but only if your device can accommodate the additional weight.
• Discharge Rating (C-Rating): The discharge rating, or C-rating, tells you how quickly the battery can release energy. If your device requires high power for motors or other demanding components, look for a high C-rating (e.g., 20C, 30C) to ensure the battery can handle the demand without overheating. Multiply the C-rating by the battery capacity to find the maximum safe discharge rate. For example, a 3S LiPo battery with a 2000mAh capacity and 20C rating can deliver up to 40 amps (2000mAh x 20C), suitable for high-drain devices.
• Connector Type: Check the battery's connector to ensure it matches your device. Common LiPo connectors include XT60, Deans, and EC3. If the connectors don’t match, you may need an adapter or connector swap, though it’s easier to choose a compatible battery upfront.
• Size and Weight: Ensure the 3S LiPo battery physically fits within the battery compartment of your device. Measure the available space and compare it to the battery’s dimensions. For devices like drones or RC cars, weight is also a crucial factor as it affects balance and performance.

What Are High-Voltage 3S LiPO Batteries And What Is Their Voltage Range?

High-voltage (HV) 3S LiPo batteries are a type of lithium polymer battery designed to operate at a higher voltage than standard LiPo batteries.

While traditional 3S LiPo batteries have a nominal voltage of 11.1V (3.7V per cell) and a fully charged voltage of 12.6V (4.2V per cell), high-voltage 3S LiPo batteries are engineered to safely reach a higher voltage, typically up to 4.35V per cell.

The voltage range for HV 3S LiPo batteries is as follows:

• Nominal Voltage: 11.4V (3.8V per cell)
• Fully Charged Voltage: 13.05V (4.35V per cell)

High-voltage 3S LiPo batteries offer benefits such as increased energy density and longer run times due to the higher voltage capacity.

However, they also require compatible chargers and careful handling, as overcharging or incorrect charging can lead to damage or safety risks.

HV LiPo batteries are often used in applications that demand higher performance, such as racing drones and RC vehicles, where every bit of extra power can enhance performance.

Long Story Short: LiPo 3S batteries can provide enough power even for the most demanding applications, at least for a very short time.

Lithium Polymer batteries are not without issues, but when used, charged, stored, and transported properly they are safe to use.

But, never underestimate LiPo batteries, even when treated properly - better safe than sorry...

3S LiPo batteries (Amazon affiliate link, opens in the new window) can be found in local hardware and hobby shops or can be ordered from online shops.