Introduction
As electric motorcycles and racing bikes push for lighter weight, faster power delivery, and quicker charging, standard battery cells often become the bottleneck. Riders demand high discharge, low internal resistance, heat stability, and long cycle life. Molicel’s newest cells (like the P45B, P50B, etc.) are designed to meet precisely those challenges.
The Problem
Traditional battery cells for e-motorcycles often suffer from:
- Voltage sag under high load,
- Excessive heat buildup during race bursts or steep acceleration,
- Long charge times,
- Reduced lifespan after frequent deep charge/discharge cycles.
These issues directly affect lap times, acceleration, reliability, and rider safety. For manufacturers and racing teams, cell choice isn’t just about peak power — it's about usable power over the full race, durability, and cooling overhead.
Who is this for?
This article is for EV motorcycle manufacturers, race teams, battery engineers, and mobility startups who want to understand cutting-edge cell tech, how to choose battery cells for racing, and how to integrate them to get maximum performance while managing risk.
Insights & Analysis
- INR-21700-P50B cell: ~5.0 Ah, energy density approx. 260–265 Wh/kg, continuous discharge up to 60 A, fast charge up to 5C, low internal resistance (~13.5 mΩ).
- INR-21700-P45B cell: slightly lower discharge/current specs than P50B, but very competitive; designed for high power with lower impedance and good cycle life.
- New lighter, higher-capacity LEV / e-motorcycle oriented cells: e.g. INR-21700-M65A (≈ 6.5 Ah), P60B (≈ 6.0 Ah) focused on range or power in light electric vehicles / e-motorcycles.
The Framework: How To Leverage Molicel Cells in Motorcycle Racing or EV Bikes
Step 1: Define Your Performance Goals
- Are you after top-speed bursts? Longer race duration? Quick acceleration from low rpm?
- Determine duty cycles, expected peak currents, ambient temperature and cooling capabilities.
Step 2: Select the Right Cell Model and Format
- If frequent high bursts, go with P50B or P45B for high continuous discharge.
- If range matters (e.g. commuter racing, dual-purpose bikes), consider M or LEV series for higher Ah.
- Check cell size (21700 vs other form factors) and pack packaging for thermal dissipation.
Step 3: Manage Thermal and Mechanical Design
- Cooling (air, liquid) is essential since even “high power” cells still heat up under heavy load.
- Use low-impedance interconnects and good tab/weld techniques.
- Ensure pack designs allow for expansion/contraction and minimize thermal hotspots.
Step 4: Optimize Charge Strategy
- Fast charge settings (e.g., 3C-5C) necessary to get rapid turnaround (pit stops etc.), but only if battery management system (BMS) supports it and thermal designs cope.
- Balance between fast charging and cell longevity.
Step 5: Monitor & Test for Durability
- Cycle life under race conditions: how many cycles at high power before degradation.
- Retention of capacity.
- Behavior under extreme temps (both cold & hot).
- Internal resistance increases over time, voltage sag, etc.
Case Study
McMurtry Spéirling PURE VP1 (track / racing prototype): uses Molicel P30B cells and demonstrates several upgrades: fast charge (≈20 min to full including cooling), lowered internal resistance (≈23% lower DCIR than prior equivalent cells), improved run time and higher continuous discharge current.
P50B showcase at CES 2024: Molicel introduced the INR-21700-P50B cell in partnership with McMurtry Automotive. Cited specs include ~260 Wh/kg energy density, >400W discharge power, and fast charging up to 5C. Intended use cases include hyper EVs, but also 2-wheeled racing or high performance motorcycles.
Practical Takeaways
- For race bikes, the P50B / P45B offer excellent performance, but expect trade-offs: cost, cooling requirements, heavy wiring/interconnects.
- Use only as much discharge current as needed — over-design for current to avoid overheating and voltage sag.
- Invest in quality BMS and wiring/tabs; small losses due to resistance or bad connections degrade real world performance fast.
- Fast charging is possible, but strong cooling & proper thermal management are required to avoid cell damage.
Conclusion
At Kelstron, we help mobility teams and motorcycle companies evaluate cell technologies, design battery packs, and integrate performance cells like Molicel’s in a way that maximizes speed, reliability, and ROI. If you’re planning to race, launch or upgrade your electric motorcycle line, let’s explore how to apply high-power cells without compromising safety or durability.