1S LiPo Batteries: Tiny Whoop Power, 3.7V vs 3.8V LiHV, and Charging Basics

A 1S LiPo battery uses a single lithium-polymer cell, so there are no series-connected cells inside the pack. A conventional 1S LiPo is typically rated at 3.7V nominal and about 4.20V fully charged, while many modern micro-FPV batteries are 1S LiHV packs rated around 3.8V nominal and up to 4.35V fully charged when the battery specifically supports that voltage.

That sounds simple, but 1S is actually one of the most specialized battery classes in RC. It dominates ultra-light platforms where every gram matters, especially Tiny Whoops and micro FPV aircraft. At the same time, a completely different branch of the hobby uses large-capacity 1S Shorty batteries in 1/12-scale pan cars.

So “1S” does not automatically mean “tiny battery.” It describes the cell count and voltage class. Capacity, chemistry, connector, discharge capability and physical format can still vary dramatically.

1S LiPo at a Glance

What Does 1S Actually Mean?

The S in LiPo battery terminology refers to the number of cell groups connected in series.

A 2S battery has two series cell groups. A 4S battery has four. A 6S battery has six.

A 1S battery is different because there is only one cell group:

For a conventional LiPo:

There is nothing to add together because no second cell exists.

This is also why a conventional 1S pack normally does not need a separate balance connector. Balance charging exists to compare and correct the voltage differences between multiple series cells. A single-cell battery has no second cell to balance against.

For the full relationship between cell count and pack voltage, see the LiPo Battery Voltage Guide: 1S to 8S Explained for RC Models.

1S 3.7V LiPo vs 1S 3.8V LiHV: This Difference Matters

One of the most important things to understand about modern 1S batteries is that not every pack labeled “1S” uses exactly the same charging voltage.

Two common versions are:

This distinction is particularly important in Tiny Whoops, because many current 1S micro batteries are LiHV packs.

Charging a conventional 3.7V LiPo as though it were a 4.35V LiHV battery can overcharge the cell. Always follow the chemistry and maximum voltage printed on the battery rather than assuming that every 1S pack should be charged the same way.

Why Tiny Whoops Use 1S Batteries

Tiny Whoops are one of the clearest examples of why 1S still matters.

These aircraft are extremely small. Adding another cell does not only increase voltage; it also increases battery mass. On an aircraft weighing only a few dozen grams, even a small weight increase can noticeably change flight behavior.

A good 1S setup can therefore offer:

• Low battery weight
• Low overall aircraft mass
• Fast throttle response
• Reduced crash energy
• Good indoor controllability
• Simple battery swapping
• Compact charging equipment

This is why 1S remains common in approximately 65mm and 75mm-class Tiny Whoop platforms and other ultra-light micro FPV designs.

But the battery still has to match more than the voltage. A Tiny Whoop battery should also be selected by:

• Capacity
• Weight
• Connector
• Battery dimensions
• Discharge capability
• Whether the aircraft expects standard LiPo or LiHV charging

A heavier 1S battery can provide more stored energy but may make a small quad feel less responsive. A smaller pack may make the aircraft feel more agile but reduce flight time.

Why Connector Choice Matters So Much on 1S

On a large high-voltage RC system, a small amount of connector resistance is only one part of a much larger electrical system. On a low-voltage 1S aircraft, the connector can have a surprisingly noticeable effect.

The reason is simple: 1S begins with very little voltage headroom.

If voltage is lost through resistance in a small connector, worn contact or thin wire, the ESC and motor see less usable voltage.

This is one reason connector condition can affect:

• Throttle punch
• Voltage sag
• Low-voltage warning behavior
• Flight time
• Consistency between packs

PH2.0

PH2.0 has been widely used on 1S micro-RC and Tiny Whoop batteries. Many existing aircraft and chargers still use this connector ecosystem.

BT2.0

BT2.0 is also common in modern performance-oriented 1S micro-FPV systems. Its popularity reflects the increasing attention paid to connector resistance and current delivery in small aircraft.

Do not choose between them only by looking at the battery specification. The battery plug must match the aircraft and charging equipment.

A physically similar connector should not be assumed to be electrically or mechanically interchangeable unless compatibility is explicitly confirmed.

1S Capacity: 300mAh, 450mAh, 500mAh — What Actually Changes?

Capacity describes how much electrical charge the battery stores. In Tiny Whoop applications, common 1S capacities may be only a few hundred milliamp-hours.

Examples:

• 300mAh = 0.30Ah
• 350mAh = 0.35Ah
• 450mAh = 0.45Ah
• 500mAh = 0.50Ah
• 650mAh = 0.65Ah

A higher-capacity pack normally carries more energy, but it also tends to be larger and heavier.

For a Tiny Whoop, that trade-off matters much more than it might in a large RC truck.

A larger battery may improve potential flight time while also:

• Increasing takeoff weight
• Reducing agility
• Changing throttle feel
• Increasing crash energy
• Changing the center of gravity

That is why the “best” capacity is usually the range the aircraft was designed around, not simply the largest pack that can physically be attached.

Not Every 1S Battery Is Tiny: The 1/12 Pan Car Exception

This is where the 1S category becomes much more interesting.

Some competition-oriented 1/12-scale pan cars, GT12 and LMP12 platforms also use 1S batteries, but these packs look nothing like Tiny Whoop batteries.

Instead of a few hundred milliamp-hours, a 1S pan-car battery can use several thousand milliamp-hours and a rigid Shorty-style hardcase format.

Why use only one cell in a race car?

Because the vehicle and racing electronics can be designed specifically around a low-voltage, high-current architecture. In this environment, 1S is not chosen because the model is tiny or underpowered. It is part of the platform design.

This illustrates an important point:

Does a 1S LiPo Need a Balance Lead?

Normally, no.

A balance connector is used on multi-cell packs so the charger can monitor the voltage of each series cell individually.

For example, a 4S battery has four cell voltages that must remain reasonably matched.

A 1S battery has only one cell.

There is therefore no cell-to-cell imbalance to correct.

This is why many 1S batteries use only their main two-wire connector for both charging and discharging.

That does not mean a 1S battery does not need voltage control. The charger must still terminate at the correct maximum voltage for the battery chemistry.

How Do You Charge a 1S LiPo Battery?

1S charging is electrically simpler than charging a multi-cell battery, but the chemistry and voltage setting still need to be correct.

For a conventional 3.7V 1S LiPo:

• Select LiPo chemistry.
• Use a charger that supports 1S.
• Confirm the correct charging current.
• Charge to the battery's specified maximum, typically about 4.20V for standard LiPo.

For a 3.8V 1S LiHV pack:

• Use a charger that specifically supports LiHV if charging to the higher HV voltage.
• Confirm the battery is actually rated for the LiHV maximum.
• Do not assume a conventional 1S LiPo charger automatically charges to 4.35V.

For more on charger selection, see Is There an All-in-One Charger for 1S to 4S LiPo Batteries?.

Why Multi-Port 1S Chargers Are So Useful

Tiny Whoop pilots often fly several short flights in one session. That changes the charging workflow.

Instead of charging one large battery, the pilot may return with six, eight or more small 1S packs.

A dedicated multi-port 1S charger can therefore be more useful than a conventional high-power RC charger, especially when each port can be configured appropriately for the battery chemistry and charging current.

The key distinction is that multi-port 1S charging is not automatically the same thing as parallel charging.

On a charger with independent outputs, each port can monitor its own connected battery. In a true parallel setup, multiple batteries are electrically combined and must meet stricter matching requirements.

Always follow the actual charger's design and instructions rather than assuming that every six-port charging device works the same way.

What Charge Current Should You Use for a 1S Battery?

The same basic charge-rate calculation used on larger batteries also applies to 1S:

Some batteries are rated for higher charge rates, but the battery manufacturer's specification should take priority over a generic rule.

Why Charger Wattage Is Usually Not the Main 1S Problem

Large 6S and 8S batteries can require hundreds of watts to charge quickly. A tiny 1S pack requires very little power.

For example, a 1S 500mAh standard LiPo charged at 1C near full voltage requires approximately:

For Tiny Whoop users, the more practical charger questions are usually:

• How many batteries can I charge?
• Does the charger support my connector?
• Can I select LiPo or LiHV correctly?
• Can I set the right current for each pack?
• Are the outputs independent?

This is very different from selecting a charger for a 6S or 8S 5000mAh battery, where output wattage becomes a primary limitation.

1S vs 2S: More Than Just Double the Voltage

Moving from standard 1S to standard 2S changes nominal voltage from 3.7V to 7.4V.

A 2S battery is therefore not a simple drop-in “upgrade” for a 1S model.

The ESC, motor and other electronics must be designed for the additional voltage. On an ultra-light aircraft, the extra cell also changes battery weight and handling.

For the full comparison, read What Is the Difference Between 1S and 2S LiPo? A Comprehensive Guide.

Can You Use 1S Instead of 2S?

Only when the electronics and model are designed to operate at 1S voltage.

A 2S model may not operate properly on 1S because the voltage may be below the intended operating range. Motors can feel extremely weak, and some electronics may not initialize correctly.

Physical connector compatibility does not prove electrical compatibility.

Can You Use 2S Instead of 1S?

Do not do this unless the complete electronics system explicitly supports 2S.

A standard 1S battery reaches approximately 4.2V when full. A standard 2S pack reaches approximately 8.4V.

That is roughly twice the pack voltage.

Connecting 2S to electronics designed only for 1S can exceed their voltage limits very quickly.

How to Choose the Right 1S Battery

You can compare current CNHL 1S 3.7V and 3.8V batteries by capacity, connector, chemistry and intended application.

Common 1S Battery Mistakes

• Assuming all 1S batteries charge to 4.2V: Many modern 1S micro packs are LiHV and may support a different maximum voltage.
• Charging a standard LiPo to 4.35V: Only use the higher voltage when the battery is specifically designed for LiHV charging.
• Thinking a 1S pack needs a multi-cell balance lead: There is only one cell to monitor.
• Assuming every multi-port 1S charger is a parallel charger: Some designs use independent outputs.
• Ignoring connector resistance: On low-voltage micro systems, poor connections can noticeably affect performance.
• Choosing the largest-capacity Tiny Whoop battery available: Extra weight can change flight behavior.
• Using 2S as an automatic upgrade: 2S roughly doubles standard pack voltage and requires compatible electronics.
• Assuming “1S” means low capacity: Competition pan-car batteries can use large-capacity 1S packs.
• Buying by connector alone: Chemistry, dimensions, capacity and weight still need to match.
• Leaving small LiPo batteries fully charged for long storage periods: Use the appropriate storage procedure when they will not be flown soon.

1S LiPo Battery FAQ

What voltage is a 1S LiPo battery?

A conventional 1S LiPo is typically rated at 3.7V nominal and reaches approximately 4.2V when fully charged.

Why are some 1S batteries labeled 3.8V?

Many 3.8V 1S batteries are LiHV cells designed for a higher maximum charging voltage, commonly up to approximately 4.35V when specified by the manufacturer.

Is a 1S battery 3.7V or 4.2V?

For a standard LiPo, 3.7V is the nominal rating and approximately 4.2V is the fully charged voltage.

Is a 1S LiHV battery 3.8V or 4.35V?

3.8V is its typical nominal rating. A compatible LiHV cell may reach approximately 4.35V when fully charged according to its specification.

Does a 1S battery need balance charging?

No cell-to-cell balancing is required because the battery contains only one cell group. It still requires a charger with the correct chemistry and voltage termination.

What is a 1S battery used for?

Common applications include Tiny Whoops, micro FPV aircraft, ultra-micro airplanes and cars, and specialized 1/12-scale pan-car racing platforms.

What connector does a 1S Tiny Whoop use?

PH2.0 and BT2.0 are both common, but the correct connector depends on the specific aircraft and battery system.

Can I charge a 1S LiHV battery on a normal LiPo charger?

A normal LiPo program generally terminates at the standard LiPo voltage rather than the higher LiHV maximum. To charge a LiHV battery to its specified HV voltage, the charger must explicitly support the correct LiHV mode.

What charge current should I use for a 450mAh 1S battery?

At approximately 1C, the charging current is 0.45A. Use a higher charge rate only when the battery manufacturer permits it.

Is BT2.0 better than PH2.0?

Connector performance can differ, but the practical choice starts with compatibility. Use the connector system specified for the aircraft and charging setup rather than changing plugs based only on the connector name.

Can I use 2S instead of 1S?

Only if the ESC, motor and complete electronics system explicitly support 2S. Never assume a 1S model can safely accept twice the standard battery voltage.

Are all 1S batteries small?

No. Tiny Whoop batteries are usually very small, but 1S Shorty batteries for 1/12-scale pan cars can have capacities of several thousand milliamp-hours.

The Bottom Line

1S is the simplest LiPo voltage architecture, but it is not a simplistic battery category.

A conventional 1S LiPo provides approximately 3.7V nominal and 4.2V fully charged, while modern 1S LiHV packs commonly operate around 3.8V nominal and may charge to approximately 4.35V when designed for it.

In Tiny Whoops and micro RC, 1S works because low weight and compact size matter more than chasing higher voltage. Connector resistance, battery mass and chemistry can noticeably influence how such a small aircraft performs.

At the opposite end of the 1S world, specialized pan-car racing shows that one cell does not necessarily mean a tiny or low-capacity battery.

The correct way to choose a 1S battery is therefore to start with the model's intended voltage and chemistry, then match the capacity, weight, dimensions and connector to the actual application.

Browse the CNHL 1S LiPo and LiHV battery range for current 3.7V and 3.8V options.

If you are considering stepping up in voltage, continue with What Is the Difference Between 1S and 2S LiPo?. For the complete voltage ladder, return to the LiPo Battery Voltage Guide: 1S to 8S Explained for RC Models.