Traxxas LiPo Battery 2S 750mAh 7.4V 20C iD Power Cell TRX2821

Overview

The Traxxas LiPo 2S 750mAh 7.4V 20C iD Power Cell Battery TRX2821 is a premium compact power solution designed specifically for Traxxas TRX-4M mini crawler models. Whether you're exploring challenging terrain with your 1/18 scale RC truck or enjoying weekend bashing sessions, this Traxxas certified LiPo battery delivers the punch and on-demand power that Traxxas models are engineered to achieve. For anyone serious about RC cars in the UK market, having a reliable spare battery is essential for extended running time, and the TRX2821 offers exceptional value and performance in a mini power pack format.

What sets this battery apart is Traxxas' exclusive iD battery system, which revolutionises how you charge and manage your RC batteries. The iD system represents the easier and safer way to charge your Traxxas batteries, eliminating confusion and compatibility issues that plague traditional RC battery charging. Only Traxxas gives you what matters most: simple installation that requires no technical knowledge, a competitive price that won't break the bank, and the most speed and runtime available in the 750mAh capacity class. This makes the TRX2821 an ideal choice for both beginners discovering the world of ready-to-run RC for the first time and experienced bashers looking for reliable spare batteries.

The 750mAh capacity provides genuine usable runtime for small-scale RC models, whilst the 2S (2-cell) 7.4V configuration matches the power requirements of the entire TRX-4M family perfectly. With a robust 20C discharge rating, this battery can deliver sustained high-drain performance without the voltage sag that compromises handling and speed on technical trails. Compact dimensions of 50mm length, 29mm width, and 13mm height mean the TRX2821 integrates seamlessly into your model's battery compartment without adding unnecessary weight or bulk.

Key Features

• Traxxas Certified iD Battery System — This battery features Traxxas' exclusive iD technology, which automatically communicates with compatible Traxxas EZ-Peak chargers to optimise charging parameters specific to this battery's chemistry and capacity. This means no manual setting adjustments, no risk of overcharging, and no guesswork—just plug, charge, and go. The iD system is the safer way to charge your batteries because it eliminates human error.
• 750mAh Capacity for Extended Runtime — The 750mAh energy capacity provides genuine runtime for small-scale crawler and trail truck models, giving you extended play sessions on a single charge. This capacity is specifically matched to the power requirements and weight of TRX-4M mini crawlers, ensuring optimal performance characteristics.
• 2S LiPo Chemistry at 7.4V — Two lithium-polymer cells in series deliver 7.4 volts nominal voltage, which is the standard power specification for TRX-4M models. LiPo chemistry provides significantly better power delivery than older NiMH batteries, with faster acceleration, higher peak power output, and improved runtime in a lighter, more compact package.
• 20C Continuous Discharge Rating — The 20C rating means this battery can safely discharge at 15 amps continuous (750mAh × 20C = 15A), providing the high-drain power delivery needed for enthusiastic driving and technical terrain challenges without voltage sag or performance loss. This rating ensures the battery can handle the demanding power requirements of brushless motors in small-scale models.
• Compact Dimensions and Lightweight — At just 50mm long, 29mm wide, and 13mm tall, the TRX2821 is engineered to fit perfectly in the battery compartment of TRX-4M models without requiring modification. The compact, lightweight design contributes to balanced weight distribution and responsive handling characteristics that small-scale crawlers depend on.
• Traxxas iD Charging Port Compatibility — When used with an optional Traxxas EZ-Peak 2-Cell iD Charging Port (sold separately), this battery can be charged using Traxxas EZ-Peak chargers with full iD automation and safety features. The battery also works with the Traxxas 2968X LiPo cell checker for real-time voltage monitoring and battery health assessment.
• Ready-to-Use Power Solution — This battery arrives fully balanced, tested, and ready to use immediately. There's no conditioning, no break-in required, and no need for specialist knowledge—simply install in your model and start driving. It's perfect as a spare battery so you can enjoy double the runtime on your RC adventures.

Technical Performance

The TRX2821 represents Traxxas' engineering excellence applied to compact LiPo battery design. The 750mAh capacity delivers appropriate runtime for 1/18 scale models without excessive weight penalty, and the 2-cell configuration at 7.4V nominal voltage is precisely matched to the electrical architecture of TRX-4M models. The 20C discharge rating is genuinely impressive for a battery of this capacity class, indicating robust internal construction and high-quality lithium-polymer cells capable of delivering sustained high-current output without voltage collapse. The chemistry and internal resistance characteristics ensure minimal voltage sag during aggressive acceleration and sustained climbing on rocky terrain, which translates to consistent handling response and predictable power delivery. The compact form factor—50mm length, 29mm width, and just 13mm height—is engineered to fit into the battery compartment of TRX-4M crawlers without modification, preserving the vehicle's intended weight distribution and handling characteristics. The iD battery system represents a major advancement in RC battery technology, embedding intelligent communication protocols that automatically identify the battery to compatible chargers, eliminating cross-compatibility issues and enabling adaptive charging algorithms that maximise cell lifespan whilst maintaining safety margins. This level of integration between battery and charger represents the kind of thoughtful engineering that distinguishes Traxxas products from generic third-party alternatives.

What's in the Box

• Traxxas LiPo 2S 750mAh 7.4V 20C iD Power Cell Battery TRX2821

What You Need to Complete

• Traxxas EZ-Peak 2-Cell iD Charging Port (TRX2821-PORT) — Required to charge this battery using Traxxas EZ-Peak chargers with iD automation. This adapter connects between the battery and charger, enabling intelligent iD charging technology.
• Traxxas EZ-Peak charger compatible with iD technology — Any Traxxas EZ-Peak charger with iD support can charge this battery when used with the charging port adapter.
• Compatible TRX-4M model — This battery is designed for Traxxas TRX-4M mini crawler models, including the TRX-4M Ford Bronco, TRX-4M Land Rover Defender, TRX-4M Chevrolet K10, TRX-4M Ford F-150, and TRX-4MT Monster Truck variants.

Frequently Asked Questions

• What is the Traxxas iD battery system and why does it matter? — The Traxxas iD system uses intelligent microprocessors embedded in the battery to communicate directly with compatible Traxxas chargers. This automation eliminates manual voltage and capacity settings, ensures each cell receives optimal charging parameters, prevents overcharging, and significantly extends battery lifespan. For UK RC enthusiasts juggling multiple batteries, the iD system saves time and removes the risk of damage from incorrect charger settings.
• Is the TRX2821 suitable for beginners? — Absolutely. The TRX2821 is specifically designed for the TRX-4M line of ready-to-run mini crawler models, which are beginner-friendly vehicles. The battery installs simply into the vehicle's compartment, requires no technical knowledge to operate, and the iD charging system is specifically designed to be foolproof. Beginners benefit from not needing to understand charging protocols or worry about damaging expensive batteries through incorrect charger settings.
• How long does this battery run for? — Runtime depends on driving style and motor efficiency, but for a 750mAh battery powering a 1/18 scale small crawler with brushless motor and appropriate gearing, typical runtime ranges from 15 to 25 minutes of continuous driving. To maximise your track time, purchasing two TRX2821 batteries allows you to swap between a charged battery and one on charge, effectively doubling your available runtime.
• What TRX-4M models does this battery fit? — The TRX2821 is compatible with the entire Traxxas TRX-4M range, including the TRX-4M Ford Bronco (all colour variants), TRX-4M Land Rover Defender (all colour variants), TRX-4M Chevrolet K10 High Trail Truck, TRX-4M Ford F-150 High Trail Truck, TRX-4MT K10 Monster Truck, and TRX-4MT F150 Monster Truck. The compact dimensions ensure perfect fit without modification.
• Do I need anything else to charge this battery? — Yes, you'll need a Traxxas EZ-Peak charger compatible with iD technology, and the optional Traxxas EZ-Peak 2-Cell iD Charging Port (TRX2821-PORT). The charging port is the adapter that connects this battery to the charger—the battery cannot be charged directly without this port. Once you have the charger and port, charging becomes as simple as plugging in and letting iD technology handle everything automatically.
• How does the 20C rating affect performance? — The 20C continuous discharge rating indicates this battery can safely deliver 15 amps of continuous current (750mAh × 20C = 15A) without overheating or excessive voltage sag. This capability is essential for small-scale models with brushless motors, enabling rapid acceleration, sustained climbing power on technical terrain, and responsive throttle feel. A higher C rating would allow even more peak power, but 20C is more than adequate for TRX-4M models.
• Can I use this battery in other Traxxas models? — The TRX2821 is specifically engineered for TRX-4M mini crawler models and may not fit or provide optimal performance in larger Traxxas vehicles. Always consult your vehicle's manual for compatible battery specifications, and never force a battery into a compartment designed for a different size. Using incompatible batteries risks damage to vehicle electronics and safety hazards.
• How do I check the battery's health? — The TRX2821 works with the Traxxas 2968X LiPo cell checker, a simple device that displays individual cell voltages and overall battery condition. Regular checking helps identify cells that may be losing capacity, allowing you to retire the battery before it fails during use. This simple maintenance extends the life of your battery collection.

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 Traxxas LiPo 2S 750mAh 7.4V 20C iD Power Cell Battery TRX2821 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.