Tesla completed the first Semi deliveries to PepsiCo at Giga Nevada last night, revealing several new details about their class 8 electric truck. One of the details that wasn’t announced was the size of the Semi’s battery pack, but in a tweet this morning Elon Musk semi-confirmed just how big it is, and as they said last night about the truck itself, it is a beast.
In a discussion about whether the size of the battery pack was shared during the event, Musk chimed in that the Semi currently has an efficiency of 1.7kWh per mile, adding that he sees “a clear path” making that number as low as 1.5kWh per mile.
Current efficiency is 1.7kWh/mile, but there is a clear path to 1.6, possibly 1.5
— Elon Musk (@elonmusk) December 2, 2022
While he didn’t answer the question of the battery pack’s size, we can make a pretty good guess with the efficiency figure he did provide.
In the lead up to the first deliveries, the Semi completed a 500-mile (804km) journey on a single charge while fully loaded at 81,000lbs. Using Musk’s figure of 1.7kWh per mile, that equates to a battery pack of around 850kWh.
We say around because additional data shared last night showed the Semi actually only used up 93% of its battery capacity, indicating it can actually travel further than 500 miles, making the battery pack likely closer to 900kWh or more.
There is now a rough estimate of the size of the Semi’s battery pack, but there are still one other key figure that Tesla has yet to release. This includes the weight of the Semi truck itself, which will impact how much cargo the Semi will be able to pull (electric semi’s can have a combined weight of up to 82,000lbs).