Backup and warning alarm BM10 and BM30

“Ears open” when it counts: The HELLA BM10 and BM30 backup and warning alarms provide additional safety in dangerous working and traffic situations with a piercing, widely perceptible alarm tone. The alarm sound is generated when reverse gear is engaged and warns both nearby people and other road users of the vehicle backing up. Backup alarms are mandatory in many countries for vehicles with an obstructed view to the rear.


The volume differs depending on the application: For example, warning systems with a volume of approx. 90 dB are often used in road traffic, and with approx. 100 dB on construction sites with high ambient noise. The HELLA BM10 backup alarm is particularly suitable for light commercial vehicles, the BM30 backup alarm for heavy commercial vehicles. The BM30 can automatically adjust the warning tone to ambient noise.


Both HELLA backup alarms have a housing of fiberglass-reinforced nylon and insulated electronics with epoxy resin. This makes them rustproof and particularly protected from moisture and vibrations.

Product Advantages

  • Penetrating, long-range alarm sound
  • Fiberglass reinforced nylon housing with integrated mounting bracket (BM30)
  • Insulated electronics with epoxy resin to protect against rust, moisture, and vibrations
  • Various sound pressure level options for city traffic and construction sites
  • Optionally with automatic adjustment to areas with changing sound levels

Technical Data

Rated voltage 12 – 48 V
Sound pressure level at 1.2 m Fixed/automatic adjustment (see program overview)
Frequency range 700 –  2,800 Hz
Power consumption 12 W
Current consumption Max. 0.6 A
Operating temperature -40 °C to +85 °C
Protection class

IP 67

Lifetime 100 h (SAE J994)
Housing material


BM30: Fiberglass reinforced nylon
Type approval


SAE J994

Program Overview


VariantSound pressure level at 1.2 mPart numberPackaging unit
with 2 screws97 dB(A)3SL 009 148-17750
with 2 screws107 dB(A)3SL 009 148-18750
140 mm cable with DEUTSCH connector97 dB(A)3SL 009 148-19750
140 mm cable with DEUTSCH connector107 dB(A)3SL 009 148-20750


VariantSound pressure level at 1.2 mPart numberPackaging unit
150 mm cable97 dB(A)3SL 996 139-21736
150 mm cable107 dB(A)3SL 996 139-22736
150 mm cable112 dB(A)3SL 996 139-23736
140 mm cable with DEUTSCH connector107 dB(A)3SL 996 139-24736
140 mm cable with DEUTSCH connector112 dB(A)3SL 996 139-25736
150 mm cable87 - 112 dB(A)3SL 996 139-26736
140 mm cable with DEUTSCH connector87 - 112 dB(A)3SL 996 139-27736