Temp Guard Multi-Sensor watches up to three batteries and sounds a loud alarm at the first sign of abnormal heat, even when the main unit sits elsewhere.
Most setups have more than one battery, and they're not always in the same place. Multi-Sensor comes with two battery sensors, with a port for a third, so each battery gets its own watch.
It also includes the remote ambient sensor, for when the main unit has to sit somewhere warmer or cooler than the batteries. The classic case is a 4WD dual battery setup, with the starting battery under the bonnet and a second battery in the back. An engine bay gets hot and wet, so the main unit goes in the cabin and the sealed remote ambient sensor goes by the hotter battery. Temp Guard then compares each battery with the air it actually sits in, not the air-conditioned cabin, which helps avoid false alarms.
Sleep through the night
Temp Guard watches every battery around the clock, so you don't have to lie awake wondering about the one you can't see.
When protection fails, Temp Guard is still watching. Most lithium batteries have a built-in battery management system (BMS), and your charger has its own protection. Most of the time they quietly do their job. But protection can fail. A cell fails, the charger keeps charging and the BMS doesn't trip. And because batteries usually live out of sight, you might not know anything is wrong until it's too late. That's why we built Temp Guard to work on its own, with its own sensors and its own power.
It checks three things at once: how hot each battery is, how fast it's heating, and how much hotter it is than the air around it. A fast temperature rise is a recognised warning sign of thermal runaway, and Temp Guard is built to catch it. The moment something isn't right, it sounds a loud alarm and lights up, giving you time to switch off, get everyone clear and call emergency services if you need them. Early warning is time, and time is what keeps people safe.
What's in the box
• Temp Guard main unit
• 2 x battery-temperature sensors
• 1 x remote ambient sensor, with double-sided tape already attached
• 3 x AAA batteries, preinstalled
• Mounting cradle, with double-sided tape already attached
• Alcohol cleaning swab for surface preparation
• 1 x quick-reference sticker
• Quick Start Card
• Warranty Card
Catches trouble early
Alarm points are set at the factory: WARNING 55 °C, CRITICAL 60 °C and RAPID EVENT 70 °C, with matching alarms for fast heating and for heat well above the surrounding air. Nothing to set, nothing to get wrong.
Keeps going when everything else stops
It runs on its own three AAA batteries, so it keeps watching even if your battery system or BMS shuts down.
No off switch, on purpose
A safety device only protects you while it's on. So Temp Guard is always on. It can't be bumped off or forgotten after a trip.
Clear lights, loud alarm
STATUS, FAULT, WARNING and CRITICAL lights tell you exactly what's happening the moment the alarm sounds.
Fits any battery
Designed for lithium, works on any battery type. It only measures temperature, and the sensors are electrically isolated, so you can fit one to any battery in a bank, even a 24 V series bank.
Looks after itself
The AAA batteries last up to 12 months with one sensor in normal use. Temp Guard tells you when they're getting low or a sensor has a fault, and a built-in watchdog restarts it if anything ever glitches.
Fit it once. Test it. Then get on with your trip. We've done the hard work to keep you safe.
Built to watch what you can't. Designed by Durst Industries Australia and backed by a 3-year Durst warranty.
ACCESSORIES SOLD SEPARATELY: a third battery sensor, 98 dB remote alarm, mounting cradle kit and Procell Intense AAA spares.
Temp Guard FAQ
1. What does Temp Guard actually do?
Temp Guard is an early-warning battery safety monitor. It checks three things at once: how hot each battery is, how fast it's heating, and how much hotter it is than the air around it. If something isn't right, it sounds a loud alarm and lights up, giving you time to switch off charging, get everyone clear and call emergency services if you need them. It doesn't disconnect the battery or put out a fire, so it works alongside your battery's own protection, not instead of it.
2. My lithium battery already has a BMS. Why do I need Temp Guard?
A BMS protects the battery, and most of the time it quietly does its job. But protection can fail. A cell fails, the charger keeps charging and the BMS doesn't trip. Temp Guard doesn't rely on the BMS or the charger. It has its own sensors and runs on its own AAA batteries, so it keeps watching even if your battery system shuts down.
3. When does Temp Guard alarm?
The alarm points are set at the factory, so there's nothing to adjust. WARNING (blue) comes on at 55 °C, CRITICAL (red) at 60 °C and RAPID EVENT (pink, blue and red) at 70 °C. It also alarms on a fast rise (1.5, 2.5 or 3.5 °C within 10 seconds) and when a battery runs well above the surrounding air (15, 25 or 35 °C hotter). Any one of these on its own sets off the alarm.
4. What should I do if the 55 °C WARNING comes on?
Treat it as a cue to check things and move the heat away. In a ventilated battery area a hot day rarely gets a battery to 55 °C on its own, so look for a heavy load, fast charging, poor airflow, a loose or corroded terminal, or a battery sitting in a hot enclosed spot. Reduce the load or charging, improve the airflow, or move the battery somewhere cooler. If you see smoke, swelling or leaking, hear hissing or notice a strong smell, switch off chargers and loads if it's safe, get everyone clear and call 000.
5. Which Temp Guard model do I need?
Standard (TG-100) suits a single battery with the main unit mounted where you'll hear it. Multi-Sensor (TG-100-MSP) suits two or more batteries, or a main unit that has to sit somewhere warmer or cooler than the batteries, and includes two battery sensors and the remote ambient sensor. Remote Alarm (TG-100-RAP) suits batteries under a bed or seat, in a canopy or in a locker, and includes two battery sensors and the 98 dB remote alarm on a 5 m lead. You can add sensors and accessories to any model later, up to three battery sensors per unit.
6. Can I fit Temp Guard to a battery box with a lithium battery I fitted myself?
Yes. The main unit can go inside the battery box, in the same air space as the battery, or outside it in its cradle on a free panel with the sensor lead fed through an existing hole or a drilled hole with a grommet. Check behind the panel before you drill and never drill into the battery or any component. The sensor ring lug goes on the battery's negative terminal, on top of the cable lug. If the unit sits outside the box, fit the remote ambient sensor inside the box so Temp Guard compares the battery with the air it actually sits in.
7. Does it work with 24 V systems or other battery types?
Yes. Temp Guard is designed for lithium and works on any battery type, because it only measures temperature. The battery sensors are electrically isolated, so you can fit one to any battery in a bank, including a series bank such as a 24 V bank made from two 12 V batteries.
8. How is Temp Guard powered, and why is there no off switch?
It runs on three alkaline AAA batteries, fitted at the factory with a pull tab. They last up to 12 months with one sensor in normal use, and Temp Guard tells you when they're getting low. There's no on/off switch on purpose. A safety device only protects you while it's on, so it can't be bumped off or forgotten after a trip.
9. Where should I mount the main unit, and how hot can it get?
Ideally in the battery box or close to the batteries, in a dry spot where you'll hear it and can reach the TEST/SILENCE button. The main unit is rated to +55 °C as its recommended operating range, matching the 55 °C WARNING point, and it keeps working above that, although long periods at high heat shorten its life. If your battery area gets hotter, such as under the bonnet, mount the main unit in the cabin and fit the remote ambient sensor by the battery. It isn't waterproof, so keep it out of bilges and wet areas.
10. Where can I find the manual, and what's the warranty?
The full Temp Guard user manual is on every Temp Guard product page under the User Manual button. Temp Guard and its accessories are covered by Durst Industries' 3-year warranty against defects (consumables such as AAA batteries, mounting tape and cleaning swabs aren't covered). See our warranty page at durst.com.au/pages/warranty for the full terms. Questions? Call 02 9660 1755 or email sales@durst.com.au.
- Watches two batteries out of the box, with a port for a third.
- Remote ambient sensor included, for a main unit mounted away from the batteries.
- Ideal for 4WD dual battery setups with a battery under the bonnet.
- Catches abnormal heat and fast temperature rises early, a recognised warning sign of thermal runaway.
- Runs on its own AAA power, so it keeps watching if your BMS or battery system shuts down.
- Always on by design. No off switch to bump or forget.
- Loud alarm with clear STATUS, FAULT, WARNING and CRITICAL lights.
- Factory-set alarm points: WARNING 55 °C, CRITICAL 60 °C, RAPID EVENT 70 °C. Nothing to set.
- Designed for lithium, works on any battery type, including 24 V series banks.
- AAA batteries last up to 12 months with one sensor in normal use, with a low-battery alert.
- 3-year Durst warranty. Designed by Durst Industries Australia.










