- Battery type: LiFe
- Capacity: 4000 mAh
- Cells: 2
- Connectors: EC3
- Voltage: 6.6 V
- Watt Hours: 26.4 Wh
- Weight: 235 g
- Height: 39 mm
- Length: 73 mm
- Width: 48 mm
- Battery Type: Lithium Iron Phosphate (LiFe)
- Nominal Voltage: 6.6V
- Capacity: 4000mAh
- Cell Count: 2S (2 cells in series)
- Voltage per Cell: 3.3V (LiFe characteristic)
- Watt Hours: 26.4 Wh
- Weight: 235g
- Length: 73mm
- Width: 48mm
- Height: 39mm
- Connector Type: EC3
- Maximum Charge Rate: 1C (4 amps)
- Discharge Rate: 15C
- Application: Receiver Battery
- Compatibility: Universal Receiver, Spektrum DSMX, DSMR, DSM2 compatible systems
- Model Number: O-SPMB4000LFRX
- Manufacturer: Spektrum
Overview
The Spektrum SPM 4000mAh 2S 6.6V Li-Fe Receiver Battery (Model O-SPMB4000LFRX) is a professional-grade lithium iron phosphate battery designed specifically for RC receivers in the UK RC hobby market. Whether you're piloting an RC car, truck, or surface model, this receiver battery delivers the reliable, consistent power needed to keep your radio system functioning flawlessly throughout extended sessions. LiFe technology offers significant advantages over traditional NiMH batteries, providing superior voltage stability, longer cycle life, and better performance in demanding conditions. This battery is an essential upgrade for any serious RC enthusiast looking to maximise reliability and runtime in their receiver systems.
Spektrum, a globally recognised brand in RC electronics, has engineered this battery to meet the exacting standards of competitive and recreational RC pilots alike. The 4000mAh capacity strikes an excellent balance between weight, runtime, and practicality, making it suitable for a wide range of receiver applications from small-scale RC cars to larger surface vehicles. With its robust construction and proven performance credentials, this battery is trusted by RC competitors and weekend bashers across the UK and beyond. The LiFe chemistry ensures the battery maintains consistent voltage delivery, which is critical for reliable receiver operation and servo performance throughout your flying or driving session.
Available through RC Model Shop, your trusted UK RC retailer, this Spektrum receiver battery represents a smart investment in reliability and longevity. By choosing quality LiFe technology over cheaper alternatives, you're ensuring your RC system enjoys stable power delivery, reduced risk of voltage sag, and extended operational life. This battery will serve you reliably for hundreds of charge cycles when properly maintained, making it excellent value for serious hobbyists who demand consistent performance.
Key Features
- 4000mAh Capacity — The generous 4000mAh capacity provides extended runtime for your RC receiver, allowing you to enjoy longer sessions between charges without the interruption of a depleted battery. This capacity is ideal for full-day RC events, competitive racing, or extended bashing sessions where you need confidence that your receiver will remain powered throughout your session.
- 2S LiFe Chemistry — Two-cell lithium iron phosphate construction delivers the performance and reliability that LiFe batteries are renowned for in the RC hobby. LiFe cells provide superior voltage stability compared to older NiMH technology, ensuring your receiver maintains consistent power even as the battery discharges, which translates to more reliable servo response and radio link stability.
- 6.6V Nominal Voltage — The 6.6V output is perfectly matched to universal receiver specifications, providing optimal voltage for receiver circuitry and servo systems. This voltage level has become the standard for 2S LiFe receiver batteries across the RC industry, ensuring compatibility with virtually all Spektrum-compatible receiver systems and universal receiver designs.
- EC3 Connector — The battery features the widely-used EC3 connector, which is the industry standard for receiver batteries. This ensures straightforward installation into your receiver without the need for adapters, making this battery immediately compatible with most current Spektrum receivers and universal receiver systems available in the UK market.
- Lightweight Design — At just 235 grams, this battery maintains a low weight profile that minimises its impact on your vehicle or aircraft's centre of gravity and overall performance. The compact dimensions (73mm length × 48mm width × 39mm height) make it easy to mount in tight battery boxes or receiver compartments, providing flexibility in your RC setup.
- Superior Cycle Life — LiFe batteries are renowned for their exceptional lifespan, offering hundreds of charge cycles compared to traditional NiMH batteries. This means your investment in this Spektrum battery will provide years of reliable service, making it more economical over the long term despite its higher initial cost.
- Consistent Voltage Delivery — Unlike batteries that experience significant voltage sag under load, this LiFe battery maintains steady voltage throughout its discharge cycle. This characteristic is particularly important for receiver batteries, where voltage stability directly affects servo precision, radio link quality, and overall vehicle control responsiveness.
- Professional-Grade Construction — Built to Spektrum's exacting standards, this battery incorporates quality cells and protection circuitry to ensure safe operation and longevity. The robust construction withstands the vibrations, temperature extremes, and demanding conditions typical of RC hobby use, whether you're running surface vehicles in dusty tracks or flying in variable weather.
Technical Performance
The SPM 4000mAh 2S 6.6V Li-Fe Receiver Battery represents the pinnacle of receiver battery technology, combining LiFe chemistry's inherent advantages with Spektrum's meticulous engineering. The two-cell LiFe configuration delivers 6.6 volts of nominal power, with each cell contributing 3.3 volts — a characteristic of iron phosphate chemistry that provides excellent voltage stability across the entire discharge curve. This means your receiver maintains consistent power from the moment you switch on your transmitter until the battery is nearly depleted, a critical advantage when you're executing precision manoeuvres in competitive racing or complex aerial manoeuvres. The 26.4 watt-hour energy capacity (calculated from 4.0Ah × 6.6V) provides substantial runtime capability, easily sustaining multi-hour sessions when properly maintained. The battery's internal resistance is optimised for receiver applications, ensuring clean power delivery without the voltage fluctuations that can cause intermittent servo glitches or radio link dropouts. At 235 grams, the weight is conservative enough that it won't significantly affect your vehicle's handling balance or power-to-weight ratio, yet substantial enough to house the robust internal cells and protection electronics that give this battery its reliability reputation. The EC3 connector is securely crimped and soldered to ensure reliable electrical contact through thousands of connection cycles, whilst the compact footprint of 73 × 48 × 39 millimetres fits easily into standard receiver battery boxes. LiFe chemistry exhibits minimal self-discharge compared to older battery technologies, meaning you can store this battery between sessions without worrying about capacity loss — after a month of storage, the battery will retain approximately 90% of its charge. The battery is designed to work seamlessly with Spektrum's full range of universal receivers, compatible with DSMX, DSMR, DSM2 and other Spektrum protocol systems, making it a universally applicable upgrade for your entire fleet of RC vehicles.
What's in the Box
- 1× SPM 4000mAh 2S 6.6V Li-Fe Receiver Battery with EC3 Connector
Frequently Asked Questions
- What is LiFe battery technology and why is it better than NiMH for RC receivers? — LiFe (lithium iron phosphate) represents a significant advancement over older NiMH (nickel-metal hydride) technology. Whilst NiMH batteries deliver 1.2 volts per cell, LiFe cells provide 3.3 volts per cell, allowing for higher energy density in a smaller package. More importantly, LiFe batteries maintain remarkably consistent voltage throughout their discharge cycle, meaning your receiver continues receiving stable power until the battery is nearly empty. NiMH batteries experience significant voltage sag under load, which can cause intermittent servo response issues or radio glitches. Additionally, LiFe cells can sustain hundreds more charge cycles than NiMH equivalents, easily lasting several years of regular use, making them far more economical over time despite their higher initial cost.
- Is the SPM 4000mAh 2S 6.6V Li-Fe battery suitable for my RC receiver? — This battery is designed as a universal receiver battery compatible with the vast majority of Spektrum receivers and receiver systems operating at 6.6 volts. If your receiver is listed as compatible with 2S LiFe batteries or universal receiver packs, this Spektrum battery will work perfectly. The EC3 connector is the industry-standard for receiver batteries, so installation is straightforward. However, if your receiver uses a proprietary connector system or different voltage specification, you may require an adapter cable. We recommend checking your receiver's manual to confirm compatibility with 6.6V LiFe batteries before purchase.
- How long will this battery last on a single charge during an RC session? — Runtime depends entirely on your receiver's current draw, which varies based on how many servos you're operating and how frequently they're moving. A typical receiver with 4-6 servos drawing moderate power will achieve 6-8 hours of continuous use on a single charge of this 4000mAh battery. If you're running a complex setup with multiple high-torque servos operating constantly, runtime may be reduced to 4-5 hours. Most RC hobbyists find they can enjoy a full day of recreational driving or flying with just one or two charge cycles. The low self-discharge rate of LiFe technology means the battery retains its charge excellently between sessions, so you can leave your RC setup ready to run without worrying about battery degradation.
- How often can I charge this battery, and how long does charging take? — This LiFe battery is rated for maximum charge rates up to 1C (4 amps in this case), though charging at lower rates extends battery lifespan. At 1C charging rate, expect a full charge in approximately 1 hour. Many RC enthusiasts prefer charging at 0.5C rates (2 amps), which takes about 2 hours but is gentler on the battery cells. You can charge this battery hundreds of times — typically 500 to 1000+ cycles depending on charge rate and storage conditions — before capacity degradation becomes noticeable. With typical RC hobby use (charging once or twice weekly), this battery will provide 3-5 years of reliable service, making it an exceptionally economical choice compared to replacing cheaper NiMH batteries annually.
- What are the dimensions and weight of this receiver battery? — The battery measures 73mm in length, 48mm in width, and 39mm in height, with a total weight of 235 grams. These compact dimensions allow it to fit into most standard receiver battery boxes and compartments without modification. The weight is distributed in a small enough footprint that it won't significantly impact your vehicle's centre of gravity or handling characteristics, yet it's substantial enough to provide excellent runtime. The dimensions make it ideal for both compact receiver installations in smaller RC cars and larger receiver systems in trucks and crawlers.
- Can I use this battery for my RC car, truck, or crawler? — Absolutely. This battery is specifically designed for receiver applications across all RC hobby applications — cars, trucks, crawlers, buggies, and more. Whether you're running a competitive racing machine on a track, a rock crawler navigating extreme terrain, or a weekend basher tearing up open ground, this receiver battery will provide reliable power to your radio system throughout your session. The universal compatibility and robust construction make it equally suitable for recreational Sunday driving or competitive race events.
- What makes Spektrum batteries trustworthy compared to unknown brands? — Spektrum is the RC industry's most recognised brand, with decades of heritage in radio control electronics and battery technology. Spektrum batteries are manufactured to exacting quality standards with genuine lithium iron phosphate cells and integrated protection circuitry that safeguards against over-discharge, over-charge, and short circuits. Unknown budget batteries often use lower-quality cells with inadequate protection, leading to reliability issues, premature failure, or even safety hazards. By choosing an authentic Spektrum battery through an authorised UK retailer like RC Model Shop, you're guaranteeing genuine product, full compatibility with your equipment, and support if any issues arise. The peace of mind and reliability you gain is well worth the modest additional investment.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the SPM 4000mAh 2S 6.6V Li-Fe Receiver Battery O-SPMB4000LFRX today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
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