Molicel B series battery cells unlock faster charging for McMurtry Spéirling PURE electric track car

Molicel and McMurtry

The new McMurtry Spéirling PURE Validation Prototype (VP1) uses the new B series of Molicel cells (INR-18650-P30B), opposed to A series (INR-18650-P26A).    The car has a charge time of under 20 mins (and this includes cooling the cells back down too).  It truly unlocks usable electric performance on track days.

The main cell level advantages with the P30B are:

  •   Boasts a significant 23% reduction in DCIR
  •   Fast charge rate raised from 2C to 3C (full SOC)
  •   Continuous discharge current up to 36A

This is possible due to a revised internal tab welding process in conjunction with refinements in the cell design and advanced materials chemistry.

The internal resistance being over 23% lower helps unlock the uplift in charge rate due to a reduced heating effect.

Managing Director of McMurtry Automotive, Thomas Yates, said “Molicel’s products offer a virtuous circle of lightweighting within our vehicle. Using Molicel’s B series technology significantly contributes to making a lightweight, compact, fast charging driver’s car with some of the most accessible performance characteristics in the world.”

Molicel and McMurtry already hold the outright record at the Goodwood Festival of Speed with an innovative electric fan car.
Comprising of thousands of cells, the battery is the largest assembly on the car.
Battery size and position influences vehicle packaging and vehicle dynamics.
Battery efficiency influences charge and discharge power limits plus cooling requirements.
And battery capacity influences all important run time.

Now, McMurtry has unveiled an improved version of that vehicle which is available for sale. It is designed for high performance track use on the world’s greatest race tracks.  The validation prototype (VP1) of the Spéirling PURE was first shown at the Goodwood Festival of Speed 2023.

The top level improvements are:

  • Top Speed Raised from 150mph to 190mph
  • Cornering G Force raised by 25%
  • Run time extended to 10 laps of Silverstone National at lap record pace
  • Fast charge in 20 mins

Improvements in the battery from both Molicel’s high power cells and also in McMurtry’s proprietary pack design enable these new figures.

This recent video from Top Gear Magazine discusses the differences between the Goodwood record car and the McMurtry Spéirling PURE VP1:


As part of the 2024 testing programme, the VP1 Prototype will also be used to attempt race track records and to demonstrate multi lap usable performance beyond the hillclimb discipline which launched the company to fame at Goodwood.

The strong partnership between McMurtry and Molicel is allowing McMurtry’s customers to access world leading EV performance and fast charging times.

Interestingly, customer’s cars will benefit from using cells which are two generations even beyond those in VP1: cells which aren’t even available on the market yet, the P50B.

The P50B is a 5.0Ah 21700 form factor lithium ion cell and which has step change improvement in charge rate, some 1.6 times greater than the P30B at cell level.   Its performance and more favourable packing efficiency can also help deliver 17% improvements in gravimetric and volumetric energy density over what’s in the existing prototype.

Further details on incorporating this development into the customer product will be communicated over the next 18 months.

Molicel President, Casey Shiue, comments:

“Molicel works with winners.  The B series represents a remarkable starting point for Molicel’s breakthrough technology on ultra-high power battery cells; we are able to keep pushing up higher capacity while having impedance even lower.

Our cells are designed to revolutionize various industries, especially in hypercar and eVTOL.  I’m confident about the potential of the B series and the positive impact it will have on our customers and their revolutionary products such as McMurtry’s Speirling PURE.

We believe it can create a brand new level of power-to-capacity ratio that will fulfill driving enthusiast’s dreams.”