The Tesla Powerwall 2 will receive a software update that increases its power output significantly, now that Powerwall usage data shows that (at least the newer) units are capable of supplying 50% more power than previously thought. The caveat is that this applies only if the ambient temperature is 30 °C. This follows the news that Tesla will also start selling solar panels and solar roofs only with Powerwalls.
Powerwall 2 peak & steady power capability is better than advertised.
Now that we have lots of operational data, Tesla can unlock higher capabilities for free via software update next month.
Depending on production date, power increase power may be >50% at 30C ambient temp.
— Elon Musk (@elonmusk) April 22, 2021
Like most power electronics, the Powerwall’s power handling capacity is limited by the temperature of its internal components including transistors, integrated circuits (ICs), and batteries. Passing more current through it causes it to get hotter, therefore only so much power can be passed through the Powerwall before it overheats. A higher ambient temperature (temperature of the surrounding environment) will raise the temperature of the Powerwall itself (to some extent). This is why Elon Musk mentioned ‘at 30C ambient temp’.
Tesla discovered that the Powerwall could theoretically supply up to 10 kW of power continuously (if allowed to by the software, which is what the update would do), and the peak power could be double that. That’s a welcome improvement from the 7.6 kW that it currently provides. What matters is that it doesn’t allow itself to overheat. Peak power cannot be sustained for any significant time period, this is just for appliances that draw large amounts of power during startup, such as air conditioners.