Features
- Smart all-in-one telemetry
- Smart Lite functionality
- Provides Spektrum Smart ESC data such as input voltage, esc temperature, esc amperage, RPM, and Text Gen Telemetry data over one wire. No additional sensors required. Smart Lite ESCs do not provide Smart Battery data.
- Integrated LED light power outputs for simple installation without the need of additional receiver ports
- Includes 2 LED Light Strings (Red and White)
- 40 Amp continuous power - ideal for 1/10 scale crawlers and scalers
- 2S-3S LiPo Compatible
- Waterproof ESC*
- Multiple options for easy programming:
- Smart ESC Programming Box
- SmartLink USB Updating and Programmer application
- Programming from Transmitter via Text Gen Telemetry
- Multi-point protection:
- Over-current protection
- Automatic LiPo low-voltage cutoff
- Thermal protection
- Failsafe protection
- Developed and designed by SpektrumT engineers, in partnership with the industry's leading ESC manufacturer
- Compact for easy installation in most applications
- Ready to install - no soldering required
- Aluminum heat sink for high efficiency
- Adjustable high-power BEC (6V or 7.4V, 4amp)
- Firmware updatable through the Smart ESC Programming Box
- High heat-resistant ICT connectors, backwards compatible with ECT connectors
- Limited 1-year warranty
Overview
The Spektrum Firma 40 amp Brushed Smart ESC is waterproof and ready to use in most 1/10th scale RC models. Featuring programming options that make it easy to tune for your on-road and off-road racers, scalers, crawlers, and bashers.
Like every component in the SpektrumT Smart ecosystem, FirmaT Smart ESCs combine "plug-and-play" simplicity with the ability to communicate with other Smart electronics - together, creating the best-performing RC system for your vehicle imaginable.
Firma Smart ESCs do much more than regulate power. They function like a virtual engineer inside your model, providing a direct path to the vital operating data you need to reach peak performance. Firma Smart ESCs give you an extra layer of confidence that your electronics are all operating at their best.
vWith Firma Smart ESCs, you'll be better connected to your vehicle than ever before - without installing extra components that all work independently of each other. You won't need extra wires, modules, or links. A Firma electronic speed control provides a one-wire solution for obtaining telemetry data such as motor current, temperature, battery voltage and capacity.
Firma ESCs not only gather the data but also send it to your transmitter in real time, instead of only storing it for after-run study. You're able to adjust settings as needed to boost performance on the go. The Firma Smart single-wire telemetry solution has been tested for quality and performance by the best brands in RC. Their verdict? Smart technology is both simpler and superior!
Video Overview
*Please see manual for Waterproof Usage Guidelines
**See compatibility chart for more information.
Overview
The Spektrum Firma 40A Lite Brushed Smart ESC is a compact, waterproof electronic speed controller designed specifically for 1/10 scale RC crawlers, scalers, bashers and off-road vehicles. This brushed ESC combines Spektrum's renowned Smart ecosystem technology with practical, user-friendly features that make it an ideal choice for RC enthusiasts across the UK. Whether you're piloting a scale crawler over challenging terrain or enjoying weekend bashing sessions, the Firma 40A Lite delivers reliable power management with integrated telemetry feedback that keeps you connected to your model's vital performance data in real time.
What sets the Firma 40A Lite apart from standard speed controllers is its Smart Lite functionality, which provides real-time telemetry data including input voltage, ESC temperature, amperage draw, RPM and Text Gen Telemetry information—all transmitted wirelessly to your Spektrum transmitter without requiring additional sensor modules or complicated installation. This means you get the intelligence of a fully-featured Smart ESC in a more straightforward package that's perfect for drivers who want functionality without unnecessary complexity. The compact design and waterproof construction make it suitable for nearly any terrain, whether you're running on rock trails, dirt, carpet or even wet conditions.
Developed and designed by Spektrum engineers in partnership with leading ESC manufacturers, the Firma 40A Lite represents the pinnacle of brushed ESC technology for medium-power applications. With 40 amps of continuous power handling, an adjustable high-power BEC, multiple protection systems and firmware update capability, this is a professional-grade component that performs reliably whether you're a seasoned competitor or discovering the world of RC for the first time.
Key Features
- Smart Lite Telemetry System — Unlike basic speed controllers, the Firma 40A Lite continuously monitors and transmits critical performance data including input voltage, ESC temperature, amperage consumption and RPM directly to your Spektrum transmitter over a single data wire, giving you the information you need to optimise performance and spot potential issues before they become problems.
- 40 Amp Continuous Power Rating — The 40 amp continuous current capacity is specifically calibrated for 1/10 scale crawlers and scalers, providing abundant power for climbing steep obstacles and maintaining consistent throttle response without thermal stress or performance degradation.
- Waterproof Design — Full waterproofing means this ESC performs reliably in wet conditions, muddy terrain and water crossings—critical for serious crawler and scaler drivers who operate in challenging outdoor environments across the UK.
- 2S-3S LiPo Compatibility — Works seamlessly with both 2-cell and 3-cell LiPo batteries, providing flexibility in your power setup whilst maintaining optimal performance across the full voltage range.
- Integrated LED Light Power Outputs — Built-in connections for LED light strings (two LED Light Strings included: one red and one white) eliminate the need for additional receiver ports or complicated wiring, allowing you to add scale lighting without cluttering your model's electronics setup.
- Adjustable High-Power BEC — The on-board Battery Elimination Circuit supplies 4 amps of current at selectable voltage outputs of either 6V or 7.4V, providing clean, regulated power to your receiver and servo systems whilst eliminating the need for a separate BEC unit.
- Multiple Programming Options — Whether you prefer the dedicated Smart ESC Programming Box, the SmartLink USB Updating and Programmer application, or direct programming from your transmitter via Text Gen Telemetry, the Firma 40A Lite offers flexible configuration methods to suit your preferred workflow.
- Comprehensive Multi-Point Protection — Over-current protection, automatic LiPo low-voltage cutoff, thermal protection and failsafe protection work together to safeguard your ESC, battery and model from damage whilst giving you confidence in reliability during extended driving sessions.
- Aluminium Heat Sink — Precision-engineered aluminium heat sink dissipates thermal energy efficiently, allowing the ESC to maintain consistent performance during high-load operations and extended runtime without thermal throttling.
- Compact Design for Easy Installation — The small form factor fits neatly into tight spaces within modern 1/10 scale crawler and scaler chassis, making installation straightforward and non-intrusive to your model's overall layout.
- Ready-to-Install Connectivity — High heat-resistant ICT connectors with backward compatibility with ECT connectors mean no soldering is required—simply plug in your battery and receiver connections and you're ready to drive.
- Firmware Updatable — Keep your ESC current with the latest features and improvements by updating firmware through the Smart ESC Programming Box, ensuring your controller benefits from ongoing Spektrum development.
Technical Performance
The Spektrum Firma 40A Lite Brushed Smart ESC represents a sophisticated fusion of proven brushed motor control technology with advanced telemetry and protection systems. At its core sits a 40-amp continuous current rating, specifically engineered for the torque demands of 1/10 scale crawler and scaler applications where smooth, controllable power delivery and climbing ability are paramount. The brushed ESC architecture provides intuitive throttle response that many experienced crawler drivers prefer, with smooth acceleration curves that translate precisely to throttle input—particularly valuable when navigating technical rock gardens and vertical obstacles where fine throttle control determines success or failure. The waterproof construction utilises high heat-resistant materials throughout, with the aluminium heat sink providing thermal management that keeps operating temperatures in the safe zone during extended running sessions. The Smart Lite telemetry system monitors input voltage with sufficient precision to provide accurate remaining battery life indication, whilst temperature sensing protects the ESC itself and alerts you to cooling issues. The adjustable BEC supporting both 6V and 7.4V output at up to 4 amps provides sufficient power for dual servos or a servo plus receiver combination without requiring external regulation. The 2S-3S LiPo compatibility covers the full range of common battery configurations for medium-power 1/10 scale models, and the low-voltage cutoff preserves battery health by preventing over-discharge. Built to Spektrum's quality standards and manufactured in partnership with industry-leading ESC specialists, this controller combines accessible simplicity with genuine performance engineering that rewards careful setup and tuning.
What's in the Box
- SPM Firma 40A Lite Brushed Smart ESC with IC3 connector
- 2 x LED Light Strings (1 red, 1 white)
- IC3 battery connector (pre-installed)
What You Need to Complete
- 2S or 3S LiPo battery with IC3 connector or IC3 connector adapter
- Spektrum receiver compatible with Smart ESC telemetry (DSMX/DSM2 protocol)
- Brushed motor suitable for your application
- Servo(s) for steering/control
- Smart ESC Programming Box (optional, for advanced programming; transmitter programming via Text Gen Telemetry or SmartLink USB application can be used as alternatives)
Frequently Asked Questions
- Is the Spektrum Firma 40A Lite suitable for beginners? — Yes, absolutely. The ready-to-install design requires no soldering, the plug-and-play connectivity makes setup straightforward, and the integrated protection systems give beginners confidence that the ESC is actively safeguarding their model. The Smart Lite telemetry provides valuable feedback that helps new drivers understand their model's performance without overwhelming complexity. However, the comprehensive programmable features also reward experienced drivers who want to fine-tune performance characteristics.
- What battery does this ESC need? — The Firma 40A Lite is compatible with both 2S and 3S LiPo batteries (2-cell and 3-cell configurations). It comes with an IC3 connector pre-installed, so you'll need a battery with matching IC3 connector or an IC3 adapter if your battery uses a different connector type. The 40-amp rating is well-suited to typical 2S or 3S packs used in 1/10 scale crawlers and scalers.
- What telemetry data does this ESC provide? — The Smart Lite telemetry system transmits input voltage (critical for monitoring battery state of charge), ESC temperature (helps identify cooling or load issues), ESC amperage (shows real-time current draw), RPM, and Text Gen Telemetry data directly to your compatible Spektrum transmitter. This is delivered wirelessly through a single data connection with no additional sensor modules required, unlike standard telemetry systems that require separate hardware.
- Does this ESC work with standard receivers? — Yes, the Firma 40A Lite is fully compatible with Spektrum DSMX and DSM2 receivers. The Smart Lite telemetry requires a compatible Spektrum receiver that supports Smart ESC telemetry, but the ESC functions normally with any Spektrum receiver if you don't need telemetry feedback.
- Is this waterproof? — Yes, the Firma 40A Lite features full waterproof construction, making it suitable for wet conditions, muddy terrain, water crossings and general outdoor use. This waterproofing is particularly important for serious crawler and scaler enthusiasts who operate in challenging UK weather conditions.
- Can I update the firmware on this ESC? — Yes, the Firma 40A Lite firmware is updatable through the Smart ESC Programming Box, allowing you to access the latest features and improvements released by Spektrum. This future-proofs your investment and ensures your controller continues to benefit from ongoing development.
- What protection systems does this ESC have? — The Firma 40A Lite includes comprehensive multi-point protection: over-current protection that prevents damage from short circuits or excessive loads, automatic LiPo low-voltage cutoff that preserves battery health, thermal protection that monitors ESC temperature, and failsafe protection that safely handles signal loss. These systems work together to safeguard your electronics investment.
- How do I programme this ESC? — You have three convenient options: use the dedicated Smart ESC Programming Box for comprehensive feature access, use the SmartLink USB Updating and Programmer application on your computer, or programme directly from your transmitter via Text Gen Telemetry if your receiver supports it. This flexibility means you can choose the method that suits your preferences and available equipment.
- What size motor should I use with this ESC? — The 40-amp rating is designed for 1/10 scale crawlers and scalers, typically paired with brushed motors in the 25-turn to 35-turn range, though the exact motor choice depends on your specific model and desired performance characteristics. Consult your model's manual or contact the RC Model Shop team for specific motor recommendations for your vehicle.
- What is the difference between the Smart Lite and standard Smart ESC? — Smart Lite ESCs provide essential Smart telemetry features including voltage, temperature, amperage and RPM in a simplified, more straightforward package. Standard full Smart ESCs add additional capabilities including Smart Battery data integration (where the battery itself communicates battery-level information). For most 1/10 scale crawler and scaler applications, Smart Lite provides all the telemetry intelligence you need without unnecessary complexity.
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 Firma 40A Lite Brushed Smart ESC, 2S-3S: IC3 P-SPMXSE40 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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