Grades D1 & D2 – System incorporating one or more interlinked mains-powered smoke alarms (and heat alarms if required), each with an integral stand-by supply. They can be hardwire-interlinked or radio-interlinked. Overall, D2 batteries are a viable alternative to the more common D cells and can be used in a variety of consumer electronics. Studies have also shown that D2 batteries have an improved environmental impact when compared to their D-cell counterparts. They contain fewer toxic chemicals and produce less waste, making them a greener option for powering devices. D batteries are larger than D2 batteries, and the two have different voltage levels. D batteries have 1.5 volts of power, while D2 batteries have 2.0 volts of power. BS 5839-6 also makes detailed recommendations in regards to wiring and commissioning of fire alarm systems, primarily in relation to Grades A and C but with some relevance to Grades D and F as well.

The battery world can be confusing! If you’re wondering if you can substitute a D2 battery instead of a D battery, you’ve come to the right place. To answer your question, the short answer is no; D2 batteries are not a direct replacement for D batteries.This document is intended as a guide to BS 5839 Part 6: 2019 and is not a substitute for reading the Code of Practice itself. Instead, it's designed to help make the implications and recommendations of BS 5839 Part 6 more clearly understood, and to offer advice on how to design, install, commission, and maintain a system that meets the requirements, with reference to the 2019 amendments. As the overwhelming number of residential applications in the UK will fall into Grades D or F, this is the area on which this guide will focus. They can also be rendered useless by the tripping of a protective device, or even – in some cases – by the fire itself.

I realize there is a lot of information here; probably most you are aware of, but I wanted to reach out because the D2 Mach 1 is a different device than what most of the forums are talking about; and appears to be serviced by Aviation; rather than outdoor/fitness; but it appears to be suffering the same battles as other 9.33 devices. BS 5839 Part 6 grades fire detection systems from Grade F up to Grade A. Generally speaking, the greater the fire risk and the more demanding the application, the more comprehensive the system needs to be. This relates to system engineering, not level of protection. FireAngel’s extensive range of optical and Multi-Sensor smoke alarms meet the required standards of the building regulations. Our Thermoptek Multi-Sensor technology has been used and trusted by the UK’s Fire and Rescue Services since 2007 and offers a faster reaction to all fire types.

Always conduct a fire risk assessment to determine risks specific to your property. The following is general advice:

Additionally, the Code recommends that after installations that include wiring, the installer should test cable insulation and earthing to ensure integrity of the system. Further tests should also be carried out to ensure correct and adequate functionality of the system as a whole. History of BS 5839-6A system of one or more battery-powered detectors powered by a user‑replaceable primary battery or batteries (such as FireAngel’s SB1-T alarm).

D2 batteries measure between 20.5–21.5mm in diameter and 47.5–50.5mm in length. Because of these size differences, you won’t find D2 batteries in the same devices that take D batteries. Professionals should adhere to the above grades when designing, constructing and managing fire detection and fire alarm systems in domestic properties. They should also be aware of the revisions made to Table 1 of The Standard, which outlines the minimum grade and category of system that should be installed to provide protection of life in typical premises. The updates have been made to reflect current living conditions. The latest updates also outline the recommendation of optical smoke alarms or Multi-Sensor fire alarms featuring an optical sensor, such as FireAngel’s SM-SN-1 (Grade D1), ST-622 (Grade F1), to be installed in circulation areas such as hallways and landings. Heat alarms should also be installed in kitchens to provide appropriate protection. Interconnected alarms should also be installed throughout a property, dependent on the specific grade, through hard-wiring or wireless connections.When it comes to battery safety, the power your device requires should always be your top priority. Using the wrong battery size can lead to safety risks or damage to your device. To avoid this, it’s best to use the specific battery size required by your device. Advantages of D2