This Aftermarket Battery Gives Your McLaren P1 (You Have One Of Those, Right?) Less Weight And More Electric Range

It feels like just yesterday McLaren was dropping off my P1 to go with my Porsche 918 Spyder and Ferrari LaFerrari, but the hybrid batteries in those cars are now old enough to warrant replacements — time flies when you're having fun, et cetera. One aftermarket firm, V Engineering, has developed a new battery for the McLaren P1 that also improves the car in two key areas: weight and electric driving range.

This aftermarket lithium-ion battery is 12.4 kWh rather than the original's 4.72 kWh. The company hasn't yet given an official number as to how many additional electric-only miles its new battery will add, but for reference, McLaren's original unit was good for six miles. Assuming a positive linear relationship between kWh and miles, quick napkin math says the new cells should be able to deliver 15.7 miles, more than the 12 miles the Porsche 918 manages from its 6.8-kWh unit. 

This new P1 battery also makes the 916-horsepower hypercar almost 51 pounds lighter. For reference, the McLaren hypercar had a listed dry weight of 3,075 pounds, which means the weight reduction here is just 1.6%, slightly less if you measure from curb weight. No, 51 pounds cut won't turn your standard P1 into a track-ready GTR overnight, but it's also not nothing — as every Miata enthusiast knows, every gram counts, and for what it's worth, a 51-pound weight reduction is absolutely something McLaren's own PR department would harp about if it was found with a new, in-house lightweight model or something. The company just touted a 26-pound savings on the new 788HS, for instance.

Based in Berkshire, England, V Engineering says despite the first P1s being built in late 2013, some of the original battery cells are as old as 2010 and therefore due to be replaced. P1s apparently become undrivable if the battery cells are deteriorated; thus why V Engineering calls its new battery program Project Continuum. The company touts itself as the U.K.'s top independent McLaren shop, said to be able to do everything from routine services to full engine rebuilds on any McLaren model.

What's more, this new battery is said to be designed to "Formula E requirements" and was developed in collaboration with engineers who actually worked on the P1 back in the day. It also uses a glycol-based cooling system for better heat management. V Engineering says customer installations will start in the spring of 2027, and says it's already "in discussions" with owners from across the world. Getting in touch with P1 owners shouldn't be too big a task since there are only, at most, 375 of us out there. DM me and I'll add you to the Facebook group.