A £1 million investment by powertrain producer Controlled Power Technologies (CPT) could signal a breakthrough for lead-carbon batteries in hybrid vehicles as the company pushes for 48V batteries in mild hybrid vehicles.
The UK-based firm says that while its switched-reluctance technology is battery agnostic, tests have shown that lead-carbon would be the ideal chemistry for the job.
“There’s a particular requirement with 48V vehicles that puts a different requirement on the battery,” said CPT’s Rob Palmer.
“With the need to constantly charge and recharge the battery, a pure lead-acid would not be suitable for the application, and lithium-ion would be too expensive for mainstream vehicles.”
Palmer said the industry is moving towards pure EVs, but is waiting for a battery breakthrough. He believes it’s going to be ten or fifteen years before it happens and mild hybrids are an interim answer.
The system harvests energy from regenerative braking to replace energy lost during acceleration, and for this there must be a 40-70% high-rate partial state-of-charge regime, something lead-carbon batteries can do well.
The technology has already been showcased in an Advanced Lead-Acid Battery Consortium (ALABC) 48V LC Super Hybrid vehicle, with an Exide Orbital spiral-wound absorbent glass matt battery featuring carbon-enhanced cathodes.
The £1million has been spent on new durability test cells at the company’s headquarters in Laindon, Essex, UK, and on maturing product and manufacturing processes, testing and simulations.
“The environmental chambers will primarily test our SpeedStart and SpeedTorq motor-generators for 48V applications,” said Paul Bloore product validation and functional safety manager within CPT’s hybrid product group.
“But we can also test at 12 volts for micro-hybrid applications, 24 volts for truck and bus applications, in fact anything up to 60 volts, which is considered the upper voltage limit for electrical machines before costly safety measures need to be incrementally implemented.”
“We have done it so that we can show that CPT can produce in low volume what can be industrialised on a bigger scale,” said Palmer. “We are demonstrating that it can be substantially scaled up.
“There hasn’t been a real battery breakthrough that has extended the range enough,” added Palmer.