Battery Testing Chambers (BTC Series)
Charging and discharging tests of batteries, such as lithium-ion batteries, are important tests to evaluate the life of batteries, and doing so over an extended temperature range ensures the safety of the end-user. Whilst running elevated tests it is equally important to consider your facilities and staff - these chambers include the most advanced protection systems on the market and are made to handle unexpected results.
As batteries become increasingly high capacity for the full-scale use of EVs, more and more safety features are required for the associated charge/discharge tests. During the tests, there is a possibility of gas leakage from the battery, ignition, smoking, explosions and other hazards. These hazards need managing - and batteries should be tested with appropriate test equipment and training.
The Espec BTC series temperature chamber is specially designed for the safe and reliable testing of rechargeable battery charge and discharge applications. It features a number of new characteristics designed with ease of use and safety in mind.
Model Summary
| Model | BTC-560Hb1 | BTC-560Vb1 | BTC-1120Hb1 | BTC-1120Vb1 | |
|---|---|---|---|---|---|
| Wind direction in the test area | Left to right | bottom to top | Left to right | bottom to top | |
| Temperture range | -40 to +100℃ | ||||
| Temperture change rate | Tenperture range | -26℃⇔+86℃ | |||
| Heat-up rate | 2.1K/min | ||||
| Cool-down rate | 2.2K/min | ||||
| Air temperture deviation | 1.5℃ | 2.5℃ | |||
| Allowable heat load | 2000W | 3000W | |||
| (stabilized at +20℃) | (stabilized at +20℃) | ||||
| Capacity | 560L | 1120L | |||
| Internal dimentions | W800×H1000×D700㎜ | W1600×H1000×D700㎜ | |||
| External dimentions | W1250×H2195×D1406㎜ | W2050×H2195×D1406㎜ | |||
| Breaker capacity | AC400V 3φ 30A | AC400V 3φ 50A | |||
| Standard equipment | 4pcs.approx.100mmφ, back side cable port | ||||
| Square cable port(Rigth/Left） | |||||
| Door lock, Large pressure-relief vent, Frost-free | |||||
| Reinforced test area floor(300kg) | |||||
| Emergency stop switch, 3-color status indicator tower | |||||
| External input/output terminal, Sheathed heater | |||||
| Ethenet port(LAN) | |||||
Additional Features
Safe environmental test
This leaflet introduces the safety features that can be added to our chambers not only based on our experience but also based on the EUCAR Hazard Level. The recommended safety features needed in the event of an abnormality in the secondary battery during tests are described. To ensure the safety of surrounding workers and installation site, we suggest adding safety features according to the EUCAR (European Council for Automotive R&D) Hazard Level.
Please contact us for more detailed information.
Provides optimal layout
In battery charging and discharging tests, the layout of the laboratory needs to be determined with the wiring to the battery cells in mind. Efficient wiring to the battery cells will increase the safety of the experimental area and save space. The position of the cable entry points in the chamber determines these factors. The BTC chamber is equipped with square cable ports on both sides and a round cable port on the back, allowing the customer to create the optimal layout.
Depending on the battery cell type placed in the chamber and the cables connected to it, the airflow in the chamber may be blocked and test quality may be affected.
In some cases, simply changing the placement of the battery cells is not the solution. The BTC chamber is allows the user to select the direction of the wind, thus suppressing the wind blockage caused by the cell shape and realizing a test with less temperature difference.
Long-term continuous operation possible with frost-free function
Charge/discharge tests are generally performed in a temperature environment of 0°C to +40°C. Equipped with a frost-free function that enables long-term continuous operation of +10°C or higher, frost on the refrigerator is prevented and continuous operation is possible without interrupting the test.
EUCAR Hazard Levels
| Hazard Level | Description | Classification criteria, effect | ||||
|---|---|---|---|---|---|---|
| 0 | No effect | No effect. No loss of functionality. | ||||
| 1 | Passive protection activated | No defect; no leakage; no venting, fire or flame; no rupture; no explosion; no exothermic reaction or thermal runaway. Cell reversibly damaged. Repair is needed. | ||||
| 2 | Defect / Damage | No leakage; no venting, fire or flame; no rupture; no explosion; no exothermic reaction or thermal runaway. Cell irreversibly damaged. Repair is needed. | ||||
| 3 | Leakage Δ mass < 50% | No venting, fire or flame; no rupture; no explosion. Weight loss < 50% of electrolyte weight (electrolyte = solvent + salt). | ||||
| 4 | Venting Δ mass ≥ 50% | No fire or flame, no rupture; no explosion. Weight loss ≥ 50% of electrolyte weight (electrolyte = solvent + salt). | ||||
| 5 | Fire or Flame | No rupture; no explosion (i.e., no flying parts). | ||||
| 6 | Rupture | No explosion, but flying parts of the active mass. | ||||
| 7 | Explosion | Explosion (i.e. disintegration of the cell) | ||||
EUCAR Level 0-2 :: Mitigations
Emergency Stop Switch
Manually stops the chamber operation. It requires the operator to manually stop the chamber.
For LiB testing, it is not that useful, since many situations where failure and hazards are imminent are are not typically visible.
Status Indicator Light
To alarm and notify people in the area the status of the chamber; i.e. Green – running, Yellow – stand by, Red – trouble. Available in various configurations; number of colours, with or without buzzer, etc.
Electronic Lock
Fitted with an electronically-operated lock mechanism, to prevent accidental opening of the door. Electronic Lock does not function as reinforcement for the main door lock.
Lever-Type Door Lock
Two-point door locking latch instead of the standard claw-type locking latch for increased strength in the event of explosions.
EUCAR Level 3-4 :: Mitigations
Gas Detector(s)
Before thermal runaway, cells typically begin to spew-out gases from the vent. When the gas(es) are detected, the chamber halts immediately to prevent thermal runaway occurring.
Typical gases that need to be detected are HC (hydro-carbons) and CO (carbon monoxide). However, other gas sensors can be present, depending on the chemistry of the cells.
Detectors are used as the trigger for chamber dampers and fire extinguishers.
Smoke Detector
When activated a trigger is sent to the chamber which turns off the refrigeration, heating, and air blower, while turning on the ventilation or fire extinguisher, depending on the configuration.
When the detector is activated, it means something is already burning inside. The fire could lead to an explosion. The test should be halted IMMEDIATELY.
Forced Air Supply / Exhaust Damper
Takes ambient air in to dilute and lower the harmful gas concentration inside the chamber. This is achieved using a blower to suck the air in from the bottom and expel it from the top.
Typical activation looks something like this:
Gas level-1: Inlet: Open + Outlet: Open
Gas level-2: Inlet: Closed + Outlet: Open
The outlet remains open in level-2 to let the fire extinguisher push out the air/gas inside.
Sheathed Finned Heater
Instead of a tubular heater, these come with fins to increase the surface area. The increase in surface area results in higher heat-transfer efficiency. That allows the temperature of the heater to be lower, which also would lower the risk of igniting any stray gases.
External Signal Terminal
Designed to send and receive alarm signals (I/O) to and from another tester such as a charge / discharge tester. This is NOT for communications, and is used for triggering between critical states.
EUCAR Level 5-6 :: Mitigations
Pressure Relief Vent
The explosion-vent is designed to release the increasing pressure during rupture/explosion of a cell in the chamber to prevent the chamber turning into a larger pressure bomb. There are three types available:
Φ100mm flapper (reusable)
300 x 300mm aluminum foil (disposable)
300 x 300mm hinged (reusable)
Extra Overheat Protector
This is an additional line from the overheat detection circuit. The sensor can detect the temperature from either the air inside the chamber or the sample placed inside.
Detecting the sample temperature provides early indication of thermal runaway.
Screw Door Lock
Bolt-on type door lock to hold the door securely in place. This is the maximum level of reinforcement we offer for the door.
As seen in the left picture, it can co-exist with the standard door lock mechanism or the Lever-Type Door Lock as its reinforcement.
CO2 / Other Fire Extinguisher
The chamber can be equipped with a trigger and cable port to be used with a customer supply fire suppression system, or we can work with local vendors in Australia to supply such a system.
This can be activated in many ways and will flood the chamber with fire suppressant.
EUCAR Level 7 :: What to do next
If an explosion does occur inside a chamber we’ll need to inspect the structural integrity to determine if it is feasible to continue using, or better to replace the system. In general, companies conducting this testing should notify their insurance companies of the activities and ensure the risk to equipment is covered in the event of a catastrophic failure.
If fitted, the viewing window will likely need replacing, as may some of the seals depending on the temperatures reached inside the chamber.