BYD’s Denza brings power saving sentry mode to discontinued N7 SUV, may come to more cars

Denza, BYD’s luxury sub-brand, has announced an upcoming over-the-air (OTA) update for the discontinued N7 SUV. Changes include a low-power sentry mode that Denza says will use less battery and reduce range compared to the current system.

The brand says the update will reach the N7 in 2027, citing the “development of multiple technologies” and the need to “maintain effectiveness across different functions” as reasons for the lengthy deployment period. The update may also roll out to other Denza and BYD vehicles.

What’s sentry mode?

Sentry mode lets a vehicle monitor movement and threats while parked, eliminating the need for dedicated dashcams and wiring kits. It typically uses a car’s built-in 360-degree parking cameras to view the outside world and stores footage in the infotainment system’s storage.

Popularised by Tesla, sentry mode is now standard on most NEVs in China. However, the system requires the vehicle’s low-voltage systems to remain active while parked, which gradually drains the battery and reduces range during operation.

From personal experience, a Deepal SL03 and its Japanese sibling, the Mazda EZ-6 (also known as the 6e), consume 2 kWh, or 15 km of range, when parked overnight with sentry mode enabled. Chinese media report that Nio cars use almost 5 kWh, or 35 km of range, with the system turned on.

Saving power

Neither BYD nor Denza have revealed how the updated sentry mode achieves its energy savings. But concerns among Chinese drivers about lost range are growing, enough that Xiaomi has used it as a selling point for its Skynomad SUVs.

The tech giant says that after 10 hours parked with sentry mode on, users lose less than 5km of range. It claims it achieved this by adding a dedicated voltage converter for the system and the SUV’s built-in fridge, which steps the traction battery’s 400+ volts down to 12V.

An isolated low-voltage path would bypass the main DC-DC converter, which powers accessories while the vehicle is in motion. It also avoids the need to “wake up” the rest of the SUV’s systems every time the 12V battery drains, which, in theory, would substantially boost efficiency.

As a purely software-based update, Denza and BYD could bring low-energy sentry mode to other models down the line. The NEV giant has already set a precedent by bringing sentry mode to previously unsupported models via OTA updates.

More on the Denza N7

The Denza N7 launched in July 2023, with its final retail price in 2026 at 259,800-289,800 yuan (39,000-43,500 USD). It was offered with single-motor RWD (230 kW / 308 hp) and dual-motor AWD (390 kW / 523 hp) powertrains, with a 91.3 kWh BYD Blade battery providing a maximum CLTC range of 702 km (~569 km WLTP).

It features BYD’s dual-gun charging tech, letting the N7 draw up to 230 kW from two separate fast chargers and gain 350 km of range in 15 minutes. The firm later replaced this with its Flash Charging network, which can deliver megawatt charging on a single plug.

Its dimensions are 4,860/1,935/1,602 mm, with a 2,940 mm wheelbase. The N7 features BYD’s DiSus-A air suspension system, and its 2025 update introduced the firm’s DiPilot 300 assisted driving system, also known as God’s Eye B in China.

According to China EV DataTracker, the Denza N7 delivered only 18,979 units in China over its four-year run, less than what the Seagull sells in a single month. The brand’s other models, like the N8L and Z9 GT, have fared much better.