The Cybertruck was the first Tesla to offer bidirectional charging, although the implementation wasn’t perfect. In particular, Cybertruck owners found that the bed outlets were unavailable while AC charging was in progress. This was a huge disappointment for people who go camping because they couldn’t power their campsite while the Cybertruck was plugged into a Level 2 charger.
One of the best use cases for electric vehicles is to power your campsite while you're on the road. With a large battery, an electric car can provide power for days of off-grid camping. That's why everyone was excited to hear that the Cybertruck would be Tesla's first Electric vehicle to offer bidirectional charging capabilities. However, when the first trucks were delivered, people discovered that Tesla's implementation of bidirectional charging was less than ideal.
More specifically, while the Cybertruck does have outlets in the bed to power various appliances, they aren’t always active. Kyle Conner of Out of Spec Studios was the first to call out this shortcoming back in January. Kyle noted that the outlets weren’t powered while AC charging, making the feature less useful. This is especially inconvenient for people who go camping a lot and see the Cybertruck as the perfect RV companion.
Indeed, having a large battery and Vehicle to Load (V2L) capability means you can theoretically power your campsite from your truck. Campgrounds typically have only one power source (if any), and EV owners often use that to keep their vehicles charged. Unfortunately, with the Cybertruck, that means a complete blackout while charging. When Conner asked Drew Baglino (then Tesla’s SVP of Powertrain and Energy), he promised that a future update would enable outlet power while charging. However, that hasn’t happened yet.
Seven months later, Wes Morrill, Tesla Cybertruck chief engineer, explained why this was more difficult than expected. First, the Cybertruck uses an AC/DC converter to convert AC power from an external source (the Level 2 charger) to DC, which is needed to charge the battery. The same hardware is also used to convert DC power from the battery to AC power to power the power outlets in the bed. However, it can’t do both at the same time; it’s either charging or V2L.
This is a boomer for anyone expecting this issue to be fixed anytime soon. Other electric pickups (the Ford F-150 Lightning, for example) run AC power from the Level 2 charger to the outlets, bypassing the AC-DC converter. Morrill revealed that the Cybertruck uses multiple power stages in the AC-DC converter and could split them to provide both charging and power, albeit at slower speeds.
As Morrill explained, Tesla thought you could power whatever devices you had from the same power source you were using to charge the truck. However, that might not always be possible, especially when all you have is a Level 2 charger. You certainly can’t plug your induction cooker into that.
The AC/DC converter used to take the AC mains and convert it to DC to charge the HV battery is the same hardware used to generate the AC mains you use for onboard power. There are several power stages in the AC/DC converter, so it may be possible to use one of them to charge at a…
— Wes (@wmorrill3) August 25, 2024