Electrifying trucking will mean sacrificing critical weight for heavy batteries, eating into already-slim margins

• A semi-truck can weigh up to 80,000 pounds. Its battery can take up to a fourth of that weight.
• An electric long-haul truck in 2030 could be up to 5,328 pounds heavier than a regular diesel truck, experts predict.

American truck manufacturers like Freightliner and Tesla are already delivering the electric trucks that the industry needs to pivot away from gas engines.

New legislation, like the Inflation Reduction Act, is encouraging the change through credits for green commercial vehicles, but the weight of massive batteries is still standing in the way.

A semi-truck including its cargo can legally weigh a maximum of 80,000 pounds. A battery for an electric truck can be up to 16,000 pounds, according to recent reporting by CNBC. That's nearly a quarter of the total weight of the truck.

The eCascadia electric semi-truck, which was released last year by truck manufacturer Freightliner, weighs up to 4,000 pounds more than a regular diesel truck, for example.

That's heavy, but less overall weight than the average electric semis, which a University of California study estimated will be more than 5,000 pounds heavier than their carbon-spewing counterparts by 2030.

That's more than 5,000 pounds less cargo on the truck. In terms of cargo, that's space for nearly 17,000 t-shirts, 16,000 apples, or one full car less than a non-electric semi-truck could carry.

The weight of the batteries "creates significant challenges economically for trucking companies," Craig Fuller, founder and CEO of FreightWaves, a supply chain data provider, told CNBC. "And they're not willing to sort of give up their ability to haul cargo and the amount of cargo they can have, just for the sake of being carbon neutral or having electric vehicles."

Even if most truckers are paid per mile driven, freight weights play an important part in determining a trucking company's profit, as some freight can be priced on a hundred-weight and volume, or on the ton-mile, and trucking companies generally have low net margin of between 2.5% and 6%.