EV Battery Sensor

Applications

Monitoring cell or module temperature in real time to prevent overheating

Feeding the reading into the BMS (Battery Management System) or TMS (Thermal Management System) so that cooling/heating can be adjusted accordingly.

Providing input for safety cutoff, balancing control, or even for state‑of‑health estimation.

Features

Tight tolerance on resistance at 25 °C (R₁₀ = ohms @ 25 °C) and on the Beta (β) constant ±1% or ±3% tolerance.

Good dissipation factor (so the sensor doesn’t self‑heat too much when current flows through it) and minimal self‑heating error.

Lead / connection options: insulated wire leads, bare leads, flat chip versions for embedding. Some may also have automotive connectors, custom cable lengths, etc.

Options

(Available on request)

Encapsulation types: epoxy coated, glass encapsulated bead, metal housing (immersion sensors), thin‑film sensors, chip (SMD) version.

Lead types: insulated wire leads, bare leads, chip without leads

Lead length, cable gauge, connector type can be customised

Resistance tolerance, Beta tolerance classes.

Rated Temperatures and Dissipation Factor

Lower Temperature : -40°C

Upper Temperature : 140°C

Max Permissible Power at 25°C : 60 mW

Resistance Tolerance (ΔR/RN ) : ±0.5%, ±1%, ±2%, ±5%

Rated Temperature (TN) : 25°C

Dissipation factor in air(δth) : approx 1.5 mW/K

Thermal cooling time constant in air (τc) : ≈ 12s

Beta Tolerance (Δβ/βN) : ±1%, ±2%, ±3%,

Heat capacity (Cth) : ≈ 18 mJ/K

Electrical Data (Resistance and Beta Values)

Resistance At 25°C (Ω)		Beta Value (25/85) (K)
2000		3540
2057		3540
2800		3900
3000		3977
4700		3977
5000		3977
10000		3977

Resistance At 25°C (Ω)	Beta Value (25/85) (K)
20000	4000
30000	4050
47000	4100
49300	3960
50000	4100
100000	4400
170000	4250

Reliability Data

Test

Standard

Test Conditions

Change In R

Remarks

Storage in
dry heat

IEC 60068-2- 2

Storage at upper
category temp
T: 100°C t: 1000 h

<2%

No Visible Damage

Storage in
damp heat,
steady state

IEC
60068 – 2- 78

Temp of air:40 °C
Relative humidity
of air: 93 %
Duration: 56 days

<2%

No Visible Damage

Rapid
temperature
cycling

IEC
60068 – 2- 14

Lower test temp:– -30°C
Upper test temp: 150°C
Time to change from
lower to upper
temperature: <30 s
Number of cycles: 1000
Medium: air

<2%

No Visible Damage

Storage in
coldness

Storage at lower
category temp T: -30 °C
t: 1000 h

<2%

No Visible Damage

Vibration
resistance

IEC 60068-2-6

Frequency range: 5 to
500 Hz
Amplitude: 7.5 mm, 2 g
Duration: 3 x 8 h

<3%

No Visible Damage

Long-term
stability
(empirical value)

Temperature: 200 °C
t: 10000 h

<3%

No Visible Damage

Voltage proof Test

1250 V AC, 1 s

<3%

No flashover

Insulation test

The sensors are placed in a
vessel containing metallic
balls of 1 mm diameter (with
total immersed head). The
applied voltage is 100 V DC.

Above
1000 MΩ

STTS	103	R1	E121	W	P	211	3435	C2
	103	R1 – 1%	E121 – Anti Rotational Type	W- FlryB Multi strand copper wire	P- Awg 20	210 MM		C2 – 3F C090 FH CL Connector
		R2 – 2%	E35 – 6.5MM Tin Plated Copper Lug(SQUARE)	K- PTFE Multi strand copper wire	H- AWG 26			C1 – XHP 2 Pin Connector
		R3 – 3%	E40 – 3mm Aluminium Tag	U -PVC Multi CORE copper wire	K – AWG 24			C6 – JST VHR 3N
		R5 – 5%	E48 – 6mm Tin Plated Copper LuG	AA- FEP Multi strand copper wire	M – AWG 22			C22 – PAP-02 V – S (JST)

Ordering Codes for NTC Thermistor Sensor For EV Battery Application

STLT *** R# E%% @@ $$$ &&&&
*** = Resistance Value at 25°C (e.g. 102- 1000Ω, 201 – 200Ω, 103 – 10kΩ)
# = Resistance Tolerance (eg. R1 – ± 1%, R5 – ±5%)
%% = Encapsulation (eg. E01 – Epoxy Powder Coated (Blue))
@@ = Type of Lead (eg. GC, G – Single strand Nickel Wire(Silver Plated) & C – 30 AWG)
$$$ = Total Length in mm (eg: 250 – 25mm Length, 401 – 400 mm Length)
&&&& = Beta Value (eg:3977K, 3830K)

EV Battery Sensor