Cell Guard - Battery Protection Sensor
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A CAN connected environmental sensor for the inside of a battery enclosure. It watches pressure, temperature, humidity and volatile organic compounds, and tells the vehicle when the air inside the pack changes in a way that matters.
A BMS watches the cells. Nothing watches the space around them. Cell voltage and temperature tell you about a cell that is already in trouble. They do not tell you that a coolant joint is weeping into the enclosure, that a seal has let water in over a winter, or that a cell has begun to vent before its own temperature has moved. Those are the failures that destroy packs, and they announce themselves in the air long before they show up in the cell data.
Detecting venting early is the headline. A cell beginning to vent releases volatile organic compounds and changes the pressure inside a sealed box. This sensor sees both, which gives the vehicle the chance to isolate the pack and warn the occupants while the event is still developing rather than after it has propagated.
Moisture ingress is the one that saves money. Water in an enclosure is slow, silent and eventually fatal. Absolute water content, relative humidity and dew point together let you see a seal failing across weeks, which is a maintenance job rather than a new pack.
It reports over CAN with a configurable bus speed and address and a supplied DBC file, so it integrates into an existing BMS network. In low power mode it monitors silently and only transmits when a threshold is crossed.
Key specifications
| Type | CAN environmental sensor for battery enclosures |
|---|---|
| Measures | Absolute pressure, air temperature, volatile organic compounds, absolute water content, relative humidity, dew point |
| Optional accelerometer | Shock load and duration up to plus or minus 24 G |
| Interface | CAN, configurable speed and address |
| Integration | DBC file supplied |
| Low power mode | Monitors silently, transmits on threshold |
| Detects | Cell venting, moisture ingress |
Features
- Sees cell venting through VOC and pressure before cell temperature has moved
- Tracks moisture ingress through humidity, dew point and absolute water content
- Configurable CAN speed and address, with a DBC file for integration
- Low power mode that stays quiet until a threshold is crossed
- Optional accelerometer to plus or minus 24 G for impact assessment
- Complements a BMS rather than duplicating it
Compatibility
For lithium ion battery enclosures in EVs and energy storage, alongside whatever BMS you are running. It is an independent sensor on the CAN bus, not a BMS function.
Thresholds are yours to set. The sensor reports; what the vehicle does about a reading is decided by your BMS or vehicle controller. Plan that logic before you fit it, because a sensor whose warnings nothing acts on has not improved anything.
Mount it in the air space, not against a cell. It is measuring the atmosphere inside the enclosure, so it needs to be somewhere that atmosphere actually circulates.
In the box
- 1 x Cell Guard sensor
Downloads
The user manual, the specification sheet, the mechanical drawing and a 3D CAD model in STEP format are all in the Documents tab. The manual covers the CAN configuration and the DBC integration.
Worldwide Shipping
Fellten offers worldwide shipping through trusted carriers including UPS, DHL, and pallet freight services. Whether you're a professional installer or a classic car enthusiast, we ensure your order is packed securely and delivered efficiently.
We are fully certified to ship dangerous goods, including lithium-ion batteries, in compliance with all international regulations.
For UK orders, most in-stock items are eligible for next working day delivery if placed before 12:00 PM. Orders placed after this time will be shipped on the next working day. Please note that all delivery estimates are stock-dependent, and you will be notified if any delays are expected.
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