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Tel : +81 3 5449 2431 Fax : +81 3 5449 2430
http://www.kashiwa-tech.co.jp

To: whom it may concern
Date: March 20th, 2023
Kashiwa Tech Co., Ltd.

Subject : Experimental test on lithium-ion-battery-powered vehicle fires withoutside air high-expansion foam fire-extinguishing system
Dear customers,We Kashiwa Tech Co., Ltd. appreciate for your continuous support to our products.
We are pleased to provide a brief report of a fire test using a Battery Electric Vehicle(BEV) powered by Lithium-ion battery (LIB) as follows. We have concluded that our highexpansion foam fire-extinguishing systems are considered effective to suppress the LIBBEV fire in this test. We will proceed with further confirmation of the effectiveness of thesystem for other types of vehicles and/or under various conditions in corporation withrelated parties in Japan and provide the IMO with information on this and future test
results.

1.

Date: The experimental test is conducted upon October 28th, 2022 (Friday).

2.

Venue: Shirosato Test Center / Japan Automobile Research Institute (JARI)

3.

Purpose:To investigate the effectiveness of outside high-expansion foam fire-extinguishingsystem against the fire on an electric vehicle (BEV) powered by lithium-ion battery (LIB).
A standard high-expansion foam fire-extinguishing system installed on existing PCCs
designed by Kashiwa Tech was used in the test.
4.

Feature of BEV fires:
The root causes of fires of BEVs equipped with LIB are various, aren’t clarified enoughyet, however, it is assumed that a short circuit inside the battery is one of the causes
because it may result in a thermal runaway which leads to a fire. When a LIB heats up,
the electrolyte inside evaporates due to heat and leaks out of the vehicle. The electrolyte,liquid and gasified, become flammable materials. The electrolyte is smoldering for a longhour, and it is said this makes more difficult to extinguish a fire by BEV comparing withthe case by a gasoline car.

5.

Test Setup:
Figure 1 shows the test setup. The test is conducted at the test center as describedabove venue, with anti-explosion facility. The test vehicle was in the midst of the wiregauze walls surrounding it (Length: 5.6 m; Width: 3.8 m; Height: 2.6 m; Area: 21 m2;
Volume: 53.2 m3. Construction: wire gauzes, with no ceiling). The test cell of the wire
gauze is of; Floor diameter: 18 m; Height: 16 m; Volume: 4069 m3; Ventilation rate: 750
m3/min. The foam generator was located horizontally on the wall facing the vehicle's
front end, 1m high from the floor.

Figure 1: Test setup

6.

Specifications of high expansion foam fire-extinguishing system:
The subject test is conducted with the same specifications as of the foam concentrate
generated by a standard high expansion foam fire-extinguishing system installed on
existing PCCs. The details are as follows:
Item
Foam generator

Specification
Discharge rate: 21 m3/min (accumulation rate: 1.0 m inheight/min) Expansion ratio: 900 times; Foam solution (98% ofsea water and 2% of foam liquid) supply rate: 23.3 L/min.

Sea water

Artificial

seawater(preparedaccordingtoIMOs

Circ.670/3.6.3)
Foam liquid

Synthetic surfactant (standard product used in Kashiwa Tech'ssystems).

7.

Test Vehicle:

Model year as in 2011-2014. Battery installed: 24 kWh, fully charged (state of health:approximately 80%)
8.

Test Summary:In this testing the fire is caused by inducing thermal runaway with overheating aheater installed in the LIB pack. Afterwards, when the thermal runaway of LIB
happened and the vehicle fire was fully intensified, the high expansion foam concentrate
was discharged.
9.

Test Procedure and Results:
The battery pack was heated by the heaters installed in it to bring about the thermal

runaway on the first cell so that the heat could be conducted to the next cell. The original
intention was to have the gaseous electrolyte blow off from the battery and get ignited by
the exposure to heated surfaces or sparks with the expectation that it would develop into
a whole vehicle fire. However, because this did not go as intended, a burner was used todirectly ignite the gaseous electrolyte.
The high expansion foam was then discharged (Figure 3) when the fire was mostintensified enough to cover the test vehicle with flames (Figure 2).
The foam started building up in the area and covering the burning vehicle andcontrolled the fire.
The foam discharge was stopped when the accumulated foam reached the top edge ofthe surrounding wall 8 minutes after the start, though the foam then partly disappeared
due to the heat from the fire.
Generation of smoke and some gasses ware observed from the test vehicle in the foam
(Figure 4). Steam the smoke and the gasses is supposed to be steam vapored from themoisture of the foam and the gasified electrolyte leaked from LIB, due to heat from thetest vehicle.
The burner was lit again when the vehicle emerged from the foam blanket to check any
flammable substances around the vehicle. Meanwhile, the front of the vehicle was ignited
spontaneously just before the burner was activated this time.
Approximately 7 minutes after the re-ignition, the fire was fully developed, and thesecond foam discharge was made on it. The second discharge was stopped because thefoam covered the vehicle in approximately 4 minutes. The burner was lit again when thefoam disappeared and the vehicle emerged from the foam blanket, but no ignition
occurred this time, indicating that the fire was completely suppressed.
The day after the test the battery pack was dismounted and disassembled forinspection, revealing that it was completely burnt out. Some of the cells were heatedagain with the flames of the burner to make sure if the flammable electrolyte still
remained, but nothing happened, meaning that no electrolyte remained.
It was confirmed that the fire was suppressed so that it might successfully hinder theignition of flammable gaseous electrolyte from the battery, to be evaporated anddismissed safely, 2hours 40minuites after the initial foam discharge, even though aburner was used to ignite.

The foam generated by our high expansion foam fire-extinguishing system not only
suppressed the electric car fire during the fire intensified, but also let the electrolyte
evaporate safely without ignition, led to early suppression of the fire. We can assume thisis realized because of the moderate cooling effect of the foam which did not seriously
disturb the evaporation of the electrolyte.
(The high expansion foam was generated from the foam concentrate with 900 times
expansion ratio, mixing with the water. This makes the density of the foam water 1/900
to/less cooling effect than the pure water.)Figure 5 shows the location of the thermocouples placed on the vehicle.
Graph 1 and Graph 2 show the temperature changes in relation to time at eachmeasurement point.
Foam Generator

Wire gauze walls

Figure 2: Test vehicle on intensified fire

Figure 3: Test vehicle submerged in foam

Figure 4: Smoke and gasses generated

10. Test steps and observation:

No.

1234567891011121314Time
elapsed(second)OperationObservation

0:00

Heater #1 turned The test commenced. The battery was heated by the(0)

on

1:33

Heater #1 turned The gasified electrolyte built up beneath the test(93)

off

22:00

Heater #2 turned(1320)

on

23:09

Heater #2 turned The gasified electrolyte built up beneath the test(1389)

off

24:00

Burner #1 turned(1440)

on

27:00

Burner #1 turned(1620)

off

40:00

Fire-fighting

The fire was fully intensified. The high expansion foam

(2400)

system turned on

system was activated and started discharge 15" later.

49:00

Fire-fighting(2940)

system turned off

1:41:00

Burner #2 turned The burner #2 was activated and ignited the gasified(6060)

on

1:43:00

Burner #2 turned(6180)

off

1:48:00

Fire-fighting

The fire was fully intensified. The high expansion foam

(6480)

system turned on

system was activated and started discharge 15" later.

1:52:00

Fire-fighting

6720

system turned off

3:10:00

Burner #2 turned(11400)

on

3:15:00

Burner #2 turned(11700)off

heater #1 attached to it.
vehicle.
Not ignited, so heater #2 was on.

vehicle.
The gasified electrolyte kept blowing off but failed toget ignited. The burner was then used to directly igniteit.
The test vehicle constantly kept burning.

The flame was extinguished, and the foam discharge
was stopped as the foam reached the top edge of thesurrounding walls.
electrolyte 1'47" later.
The test vehicle constantly kept burning.

The flame was extinguished, and the foam discharge
was stopped as the foam reached the top edge of thesurrounding walls.
The burner #2 was lit to make sure if any flammable
substance still leaked, but no ignition occurred (the firewas completely suppressed).

11. Temperature Data:

Figure 5: Thermocouple arrangement

Graph 1 Temperatures on the test vehicle

Graph 2 Temperatures in the battery packPlease kindly contact below person if you had any inquiry related with this report.
Sincerely yours,
Katsuyuki Machida (Mr.) *Overseas Sales Departmente-mail: machida@kashiwa-tech.co.jp
Tel: 03-5449-2431*Optional contact:e-mail: sales@kashiwa-tech.co.jp
Inquiry via the company's website: https://kashiwa-tech.co.jp/en/contact/contact-product/

End of the report