BYD Seagull Sentry Mode: Conditions, Reserve and Privacy

BYD Seagull Sentry Mode: switching it on isn't enough, and footage has limits

Scope: BYD China-mainland 2026 Seagull; official website owner's manual file 260317; physical PDF pp. 34–36, "Sentry Mode"; only vehicles equipped with Sentry Mode; asterisked equipment, screens and software depend on the actual vehicle and official confirmation; not extended to other model years or markets

Switching it on still needs conditions to be met

The car is parked and the phone shows the function was switched on, so why is there no recording when you expected one? The manual defines Sentry Mode as a parking security monitoring aid, and requires all of the following at once: the car switched off and locked, a valid memory card with enough free space, and charge no lower than the minimum reserve set on this car. Checking one switch does not show every condition is met. We suggest recording each of these states once safely parked, rather than reading a missing notification as a camera fault, or treating a monitoring aid as a guarantee of security while parked. ^[1]

Automatic stop and the next activation are different

The manual explains that Sentry Mode stops automatically when consumption reaches the set reserve; the minimum reserve depends on this car's setting, so a fixed percentage from the internet can't be copied. The activation cycle is a separate setting: always on means it activates every time the car is switched off and locked, while once applies only this time. The first answers how far down the charge it can run; the second answers whether it will be enabled again next time you park. A fault report can state both settings and the charge level when it stopped; even if the figures match, that alone can't rule out other problems, and don't test the car's charge limits to extend monitoring. ^[1]

Check the parking location and mirror space too

The manual requires you to judge whether the parking environment is suitable before use, and explicitly prohibits use where information about important sensitive areas is involved, such as military administration zones, defence science and industry units, and Party and government bodies at county level and above. Once enabled, the mirrors may unfold for monitoring, and the manual asks you to watch the clearance on both sides; for cars without electric folding mirrors there is separate advice on unfolding them by hand, so it cannot be assumed every version moves them automatically. If the location is restricted or space is tight, sort out these conditions first, and don't trigger the function repeatedly in a restricted place to test recording. ^[1]

A notification doesn't make footage free to share

According to the manual, risk-event videos are stored only on the memory card in the car and need to be kept safely, so a phone push notification is not proof that the video has been backed up. The manual also warns against spreading or sharing footage with third parties, and prohibits using it to infringe others' rights or spread private information or illegal content. Where an incident needs handling, we suggest asking the official service or the relevant authority about lawful ways to obtain and keep evidence, rather than uploading footage of passers-by, number plates or locations to social media. This article gives no methods for getting round location restrictions, changing storage or flashing firmware to extend monitoring. ^[1]

Sources

[Source 1] BYD China official website: 2026 Seagull Owner's Manual (in Chinese) (public PDF on the official website)
https://www.byd.com/material/domestic-official/user-manual/ocean/2026%E6%AC%BE%E6%B5%B7%E9%B8%A5%E7%94%A8%E6%88%B7%E6%89%8B%E5%86%8C260317.pdf
Publication date unknown; information checked at 2026-10-07T07:12:15Z, which is not the publication date.

Suggestions on record-keeping, enquiries and service choice are editorial opinion, not a manufacturer procedure.