Ajax Alarm Maintenance: The UK Installer's Battery & Service Guide
An Ajax system that nobody looks after for five years ends with a flat detector, a low-battery fault on every arming and an annoyed customer. This guide covers Ajax alarm maintenance for UK installers: which battery each Ajax detector, keypad and siren takes and how long it is rated for, how the system warns you before a cell runs out, how long each hub keeps going on its backup battery, and what a remote check and an on-site service visit should include under BS 9263. It is written for installers building a maintenance contract and for end users who want to know what a service involves. Every figure comes from Ajax Systems or the British Standards Institution and is cited next to the claim.
What this guide covers
- Battery life by device: from up to 1.5 years on a KeyPad TouchScreen to up to 10 years on a sealed FireProtect 2 SB, with the cell type for each.
- Low-battery warnings: the app warns at roughly 10% charge, which Ajax say leaves up to about two months to change the cells.
- Hub backup power: Hub 2 and Hub 2 Plus run for 14 to 16 hours on the built-in battery, and much longer with Battery power saver — with a Grade 3 catch.
- Service frequency: what BS 9263 expects for Grade 2 and Grade 3 systems, and where a remote check can replace a site visit.
- The checklist: a step-by-step service routine, a van kit list and the mistakes that shorten battery life.
What does Ajax alarm maintenance involve?
Ajax alarm maintenance is four jobs: keeping detector batteries in date, proving the hub backup battery and power supply, checking radio links and detection, and keeping a written record of every visit and remote check. Because Ajax detectors are wireless and battery powered, most of the work is planned battery replacement rather than fault finding — and because every device reports its battery level and signal strength to the hub, much of the inspection can be done before you arrive.
For installers this is the recurring-revenue side of the business. A system installed today will need a full set of cells at some point in its life, the customer’s insurer or police-response scheme may require a set number of service visits each year, and a customer who gets a call before the low-battery fault appears is a customer who renews. For end users, it is the difference between an alarm that works on the night it matters and one that has been quietly reporting a fault for months.
How often should an Ajax alarm be serviced?
At least once a year, and twice a year (or once plus a remote check) for police-response Grade 2 systems and all Grade 3 systems. Servicing of UK intruder and hold-up alarms is covered by BS 9263:2016, the BSI code of practice for commissioning, maintenance and remote support. As summarised in published installer service terms quoting clause 6.4, the visit frequencies are:
| System | Maintenance under BS 9263 clause 6.4 |
|---|---|
| Grade 2 (PD 6662), no police response | One site visit per year |
| Grade 2, PD 6662:2017 notification options A, B, C or D | Two site visits per year, or one site visit plus one remote system check |
| Grade 3 | Two site visits per year, or one site visit plus one remote system check |
The same source notes that records of maintenance, remote support and any temporary disconnection should be kept for at least 15 months. Treat the table as a guide and check the clause in your own copy of the standard and your certification body’s rules (NSI, SSAIB or similar) before writing a contract. If the system is monitored for police response, our Ajax PD 6662:2017 and police response guide explains the notification options in more detail.
Which batteries do Ajax detectors use, and how long do they last?
Almost every Ajax wireless device runs on disposable lithium cells — mostly CR123A, with AA, AAA and CR2032 in keypads, leak detectors and key fobs — while hubs and range extenders use a rechargeable backup battery. The table below lists the devices we stock with the battery set and calculated life Ajax publish in their battery life article and service-life table. Calculated life is an upper figure under default settings, not a guarantee.
| Ajax device | Battery set | Calculated life |
|---|---|---|
| MotionProtect U / MotionProtect Plus U | 1 × CR123A | Up to 5 years |
| CombiProtect | 1 × CR123A | Up to 5 years |
| DoorProtect U / GlassProtect U | 1 × CR123A | Up to 7 years |
| DoorProtect Plus U | 1 × CR123A | Up to 5 years |
| MotionCam U | 2 × CR123A | Up to 4 years |
| MotionProtect Outdoor | 2 × CR123A | Up to 6 years |
| DualCurtain Outdoor | 2 × CR123A | Up to 4 years |
| MotionCam Outdoor (PhOD) | 4 × CR123A | Up to 3 years |
| KeyPad Plus | 4 × AA | Up to 3.5 years |
| KeyPad TouchScreen | 6 × AA | Up to 1.5 years |
| SpaceControl key fob | 1 × CR2032 | Up to 5 years |
| HomeSiren U | 2 × CR123A | Up to 5 years |
| StreetSiren DoubleDeck | 4 × CR123A | Up to 5 years |
| LeaksProtect | 2 × AAA | Up to 5 years |
| FireProtect 2 RB (Heat/Smoke/CO) | 2 × CR123A (replaceable) | Up to 7 years |
| FireProtect 2 SB (Heat/Smoke/CO) | 2 sealed lithium batteries | Up to 10 years |
Two things stand out for planning. First, the keypads and the photo-verification detectors are the short-life devices on most sites, so they set the rhythm of your battery visits. Second, the FireProtect 2 SB has non-replaceable cells: at the end of its life you replace the detector, not the battery, so put the install date on the job sheet.
How does an Ajax system warn you about a low battery?
When a device drops to roughly 10% charge, the user gets a notification in the Ajax app and a malfunction message goes to the monitoring centre each time the system is armed. Ajax say that, depending on settings and conditions, this leaves the owner about two months to change the cells (Ajax: when and how to replace cells).
That two-month window is the installer’s opportunity. If you have PRO access to the customer’s hub, battery levels are visible in the device list in the Ajax PRO app and Ajax PRO Desktop, so you can book a visit as soon as a device starts to fall rather than waiting for the customer to ring about a fault that blocks arming. On a monitored site, a low-battery malfunction on every arming also generates work for the alarm receiving centre, which is a good reason to keep ahead of it.
How do you replace the battery in an Ajax detector?
Replace the whole set with fresh cells of the same type and the same manufacturer, never a mix of old and new. Ajax warn that installing any cell type other than the one a device is designed for may damage it, and that one discharged cell in a multi-cell battery can significantly reduce the life of the whole set (Ajax battery guidance).
- Tell the hub first. Opening a detector trips its tamper. Put the system into a state where a tamper will not send an alarm, or tell the monitoring centre you are on site.
- Check the device’s battery spec. Most intruder detectors take CR123A; keypads take AA or AAA; key fobs and Buttons take CR2032. Check the device page or the table above before you open it.
- Change every cell in the device. Fit cells from one batch and one manufacturer, observe polarity, and close the casing so the tamper restores.
- Wait for the hub to read the new level. The battery percentage updates on the next ping; confirm it in the app before you leave.
- Record it. Write the date and the device on the service record so the next replacement can be planned.
Ajax’s calculated battery life assumes the specific cells they recommend, which include Panasonic and Huiderui CR123A cells and Energizer Ultimate Lithium AA; other cells may give a different operating time. We stock a CR123A 3 V lithium cell for detector and siren replacements, and a CR2 3 V lithium cell for older systems with the first-generation FireProtect, which Ajax list as taking two CR2 cells plus a CR2032.
What shortens Ajax battery life, and how do you fix it?
Battery life falls when a device uses its radio more often or works harder: frequent alarms, a short ping interval, weak signal, low temperature and settings such as Always active all drain the cells faster. Ajax explain that transmit power is adjusted automatically to the signal, so a detector at the edge of range spends more energy on every message (Ajax: batteries and communication with the hub).
| Cause | What it affects | Fix at the service visit |
|---|---|---|
| Weak Jeweller signal (one bar) | Every device | Move the device or add a ReX 2 range extender |
| Always active switched on | Motion and glass-break detectors | Use it only where 24-hour detection is genuinely needed |
| Entry delay on a hallway PIR | Motion detectors | Ajax note the detector triggers on every disarm; expect shorter life on the entry route |
| Cold location (below −10 °C for opening detectors) | Opening detectors, key fobs | Fit on the inside face of the door or window, never outside |
| Noisy room with Always active glass-break | GlassProtect, CombiProtect | Ajax say life can halve; review the setting |
| Extra photos and photo-on-demand | MotionCam range | Match the photo count and quality to what the monitoring centre needs |
| Arming chimes and LED indication | Sirens | Turn off indication the customer does not use |
Most of these are commissioning decisions, which is why a service visit is also a chance to correct the original setup. If a detector keeps returning to one bar of signal, our Ajax signal strength and ReX 2 range guide covers placement and extenders in detail, and the MotionCam photo verification guide explains the photo settings that drive battery use.
How long will an Ajax hub run on its backup battery?
Under Ajax’s test conditions, a Hub 2 (2G) runs for up to 16 hours on its built-in battery, a Hub 2 (4G) for up to 14 hours and a Hub 2 Plus for up to 15 hours (Ajax: how a system operates in a power outage). Those figures assume default polling and ping intervals, two devices, the system disarmed and only the cellular channel active, so a busy real-world system will see less.
| Hub | Backup battery, standard | With Battery power saver |
|---|---|---|
| Hub 2 (2G) | Up to 16 hours | Up to 70 hours |
| Hub 2 (4G) | Up to 14 hours | Up to 100 hours |
| Hub 2 Plus | Up to 15 hours | Up to 80 hours |
Battery power saver puts the hub into standby when mains is lost and wakes it on any device event. Ajax are clear that with the feature enabled the system does not comply with EN 50131 Grade 3, and that while in standby the hub is not connected to the Ajax Cloud or the monitoring centre until an event occurs — so leave it off on Grade 3 and monitored sites, and use it where long outages matter more than constant connection. Ajax also let you delay the external-power-loss notification by between 1 minute and 1 hour on OS Malevich 2.22 or later, which cuts nuisance messages from short blips (same source).
The hub battery is rechargeable and recharges automatically when mains returns, but it ages. We stock the replacement Ajax battery for Hub 2 Plus and Hub 2 (4G). Where a site has no stable mains, or the customer wants the hub on a UPS or a 12 V supply, use the Ajax 12 V power supply adapter for Hub 2, Hub 2 Plus and ReX 2 or, for older first-generation hubs, the 12 V adapter for Hub, Hub Plus and ReX. Ajax state that a PSU lets a hub or range extender run from 6, 12 or 24 V networks, a UPS or a vehicle supply (same source). For help choosing between the hubs, see Ajax Hub 2 vs Hub 2 Plus.
What should a remote Ajax maintenance check include?
A remote check should review every device’s battery level, signal strength, online status and tamper state, the hub’s power and communication channels, the firmware version and the event log since the last visit — all of which are visible to an installer with PRO access in the Ajax PRO app or Ajax PRO Desktop. Done properly, it is the half of the BS 9263 schedule that can replace a second site visit on Grade 2 police-response and Grade 3 systems.
- Batteries: list any device below a comfortable margin and book the replacement visit.
- Signal: look for devices that have dropped from three bars to one since commissioning — furniture, foil blinds and new partitions change radio paths.
- Power: check the hub is on external power and that there have been no repeated power-loss events.
- Communications: confirm every channel you sold (Ethernet, Wi-Fi, 2G/4G) is connected, because a dead SIM is invisible to the customer until the broadband fails.
- Events: scan for repeated false alarms, tamper events or comms losses from one device.
- Record: log the date, what was checked, any configuration change and who carried it out.
The record matters as much as the check. BS 9263 expects the date and time, the checks undertaken and their results, any configuration changes and the identity of the person doing the work to be recorded, and kept for at least 15 months (clause 9 summary).
What does an on-site Ajax service visit include?
An on-site visit proves that the system still matches its as-fitted record and that every part works end to end: tampers, setting and unsetting, entry and exit, power supplies, detectors, warning devices and every alarm transmission path. That list follows the preventive checks in Annex B of BS 9263, as quoted in published BS 9263 service terms, and it maps neatly onto Ajax’s built-in tests.
- Detection zone test on every motion detector. Ajax describe the LED staying lit during the test and going out when motion is detected, with an in-app pop-up on current firmware and apps (Ajax: checking a detector after installation).
- Jeweller signal strength test at each device — two to three bars is the target.
- Signal attenuation test where available. Ajax base this on EN 50131: it artificially lowers transmitter power to prove the link has margin, and Ajax recommend running it with the signal strength test (Ajax: what is the attenuation test).
- Tamper check on at least one device through to the hub.
- Set, unset, entry and exit from each keypad, fob and the app, and offer the user a refresher.
- Sirens — sound each siren briefly with the customer warned.
- Power — pull mains on the hub and confirm the switch to battery is reported, then restore it.
- All transmission paths — test each channel to the monitoring centre or app separately.
- Visual inspection — brackets, damage, damp, new obstructions and changed room use.
Leave every device as you found it. A detector left in test mode or a siren left muted is the most common reason a just-serviced system fails.
Which Ajax devices need special attention at a service visit?
Keypads, outdoor detectors, photo-verification detectors and fire detectors deserve a closer look, because they either have the shortest battery life or carry life-safety duties. A KeyPad TouchScreen is rated for up to 1.5 years on six AA cells, so on a busy site it may need cells at every annual visit; the KeyPad Plus is rated for up to 3.5 years (Ajax service-life table). Our Ajax keypad comparison helps you pick the right keypad for the traffic at each entrance.
Outdoor detectors such as the MotionCam Outdoor are rated for up to 3 years and live with weather, spiders and growing hedges, so clean the lenses and re-walk the detection area at every visit (see our Ajax outdoor detectors guide). For fire, the FireProtect 2 RB takes replaceable CR123A cells while the SB is sealed for up to 10 years; test the sounder and record the detector’s age. Commercial EN 54 systems built on the Ajax EN54 Fire Hub are serviced under the fire-alarm standard rather than BS 9263, and we stock the Fire Hub’s 24-hour internal backup battery and 72-hour internal backup battery; our wireless fire alarm systems guide covers that side.
Ajax alarm service checklist
- Run the remote check the day before: note every device below a comfortable battery level and anything showing one bar of signal.
- Load the van with the right cells for those devices, plus spare CR123A and CR2032 cells.
- On site, tell the monitoring centre and the customer before you open anything.
- Run the detection zone, signal strength and, where available, attenuation tests on every detector.
- Replace cells as a full set per device, from one batch and one manufacturer.
- Test sirens, tampers, keypads, fobs, entry and exit, and each transmission path.
- Pull mains on the hub, confirm the power-loss event, restore it and confirm the restore.
- Check the as-fitted record still matches the building — new walls and changed rooms change coverage.
- Take every device out of test mode, then arm and disarm the system with the customer watching.
- Complete the service record and give the customer a copy, then diary the next visit or remote check.
What should be in an Ajax service van kit?
Carry the cells, spares and power parts that turn a fault-finding trip into a one-visit fix. A practical kit for a mixed Ajax customer base:
- CR123A lithium cells — the main detector and siren cell.
- CR2032 coin cells for SpaceControl fobs and Buttons, and AA and AAA lithium cells for keypads and LeaksProtect.
- A replacement Hub 2 Plus / Hub 2 (4G) battery for older hubs.
- A ReX 2 for sites where a detector has drifted to one bar.
- A spare MotionProtect U and DoorProtect U to swap out a damaged device on the spot.
- Cleaning cloths and a small brush for outdoor detector lenses.
Five mistakes that shorten Ajax battery life
- Mixing old and new cells. One tired cell drags down the whole set.
- Fitting the wrong cell type. Ajax warn it can damage the device.
- Leaving Always active on everywhere. It keeps detectors transmitting when nobody needs them to.
- Ignoring a one-bar signal. The device spends more energy on every message for the rest of its life.
- Waiting for the customer to call. By then the fault has been blocking arming or nagging the monitoring centre for weeks.
Frequently asked questions
How long do Ajax detector batteries last?
It depends on the device: Ajax quote up to 5 years for MotionProtect, up to 7 years for DoorProtect and GlassProtect, up to 4 years for MotionCam and up to 1.5 years for KeyPad TouchScreen, under default settings.
What battery does an Ajax MotionProtect take?
One CR123A 3 V lithium cell. DoorProtect, GlassProtect and CombiProtect also take a single CR123A.
How much warning do you get before an Ajax battery runs out?
The app warns at roughly 10% charge, and Ajax say that leaves about two months to replace the cells, depending on settings and conditions.
Can I fit any brand of CR123A in an Ajax detector?
The correct cell type will work, but Ajax calculate battery life with specific recommended cells, so other brands may give a different operating time. Always replace the full set with one type from one manufacturer.
How often does an Ajax alarm need servicing?
At least once a year. Grade 2 systems on a police-response notification option, and Grade 3 systems, need two visits a year or one visit plus one remote check under BS 9263.
How long does an Ajax Hub 2 Plus last in a power cut?
Up to 15 hours on its built-in battery under Ajax’s test conditions, or up to 80 hours with Battery power saver — which is not compatible with Grade 3.
Related guides
- Ajax Wireless Alarm Systems: The Complete UK Installer Guide
- Ajax Signal Strength & ReX 2: The UK Installer’s Radio Range Guide
- Ajax PD 6662:2017 & Police Response: The UK Installer’s Guide
- Pet-Friendly Alarm Systems: The Ajax Installer’s Guide to Fewer False Alarms
- Ajax LeaksProtect: The UK Installer’s Guide to Water Leak Detection
Order Ajax batteries, spares and hubs from Netview
Netview is an authorised UK Ajax stockist based in Leicester. CR123A cells, the Hub 2 Plus replacement battery, hub power adapters, ReX 2 range extenders and the full Ajax detector, keypad and siren range are held in stock for same-day dispatch, with trade pricing for installers. Plan a new system with the Ajax system builder, or browse the full range at netviewcctv.co.uk.
About the Author
