General Motors and Honda are expanding their partnership to include a line of affordable EVs for North America covering what the automakers say are the most popular vehicle segments.

Scheduled to go on sale in 2027, these vehicles will be based on "a new global architecture using next-generation Ultium battery technology," GM and Honda said in a press release.

The two automakers aim to build "millions" of EVs based on this architecture across multiple segments, including a compact crossover, the release said.

General Motors' BEV3 platform and Ultium batteries

General Motors' BEV3 platform and Ultium batteries

GM and Honda will also discuss battery-tech collaborations to reduce costs, improve performance, and increase sustainability, according to the companies, adding that both are making progress on new battery tech independently.

GM said it is working with lithium-metal, silicon, and solid-state cells, as well as more flexible production methods. Honda said it has established a demonstration line for solid-state cells in Japan and is making progress toward mass production. The automaker previously said it aimed to offer solid-state cells in production vehicles later this decade.

The two automakers have been working together since 2013, when they began collaborating on hydrogen fuel-cell tech. That expanded to battery tech in 2018, with an agreement to collaborate on next-generation batteries, and Honda agreeing to buy battery modules from GM.

General Motors Ultium batteries

General Motors Ultium batteries

In 2020, they announced a partnership on development and supply-chain costs encompassing fuel cell, battery-electric, and internal-combustion vehicles. Honda will also use GM's Ultium tech, culminating in two EVs built in North America that will go on sale in 2024, and adopt a version of GM's Super Cruise driver-assistance system.

The first of the two codeveloped EVs for 2024 will be the Honda Prologue, which will be followed shortly after its launch by an Acura EV. A previous report said Honda was targeting 70,000 annual U.S. sales for the Prologue, which will be the automaker's first U.S.-market EV since the discontinuation of the Clarity Electric after the 2019 model year.