THOR 403542 3.7V 550mAh lithium polymer battery with PCM protection, red and black lead wires, and 2-pin connector

THOR 403542 3.7V 550mAh LiPo battery dimension drawing showing T×W×L = 4.0 × 35 × 44 mm (with PCM) and 2-pin connector polarity

Customizable LiPo battery connector and wire harness options, with PH 2.0 mm shown for reference

Lithium polymer (LiPo) battery connector polarity guide showing red positive and black negative wires with correct and incorrect connection examples

Exploded multilayer structure of a LiPo pouch cell showing tabs, pouch film, electrodes, separator, current collectors and insulating layers

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Description

Choose THOR-403542 when a 4 × 35 × 42mm bare-cell envelope fits a shallow, near-square cavity and the design needs 550mAh. Compared with THOR-303442 (3 × 34 × 42mm, 350mAh), it accepts 1mm more nominal thickness for additional capacity; THOR-403442 keeps a closely matched 4 × 34 × 42mm geometry while increasing nominal capacity to 700mAh. Select among them by confirmed cavity dimensions and runtime needs, not by assuming discharge capability.

The 4 × 35 × 42mm figure is the nominal bare-cell envelope. The current PCM-equipped drawing shows approximately 4 × 35 × 44mm, while PCM placement, insulation, connector body, lead-wire exit and bend radius determine the final assembly space. Allow for manufacturing tolerance and normal pouch-cell expansion, and verify that nearby ribs, fasteners, displays, antennas or PCB components do not obstruct installation.

The 550mAh rating provides 2.04Wh at 3.7V nominal, but actual device runtime depends on load profile, regulator efficiency, system cutoff voltage, wireless or radio duty cycle, operating temperature, and battery aging. Before approving samples, confirm continuous current, peak current, connector family and pitch, polarity, wire length, wire exit direction, PCM requirements, and whether an NTC thermistor is needed. THOR Power can configure these integration details for the OEM design. Final pack dimensions and electrical limits must be confirmed in the approved engineering datasheet.

THOR-403542 Engineering & Fit Questions

What are the bare-cell and finished dimensions of THOR-403542?

The nominal bare-cell envelope is 4 × 35 × 42mm. The current PCM-equipped drawing shows approximately 4 × 35 × 44mm. Final clearance also depends on PCM placement, insulation, connector body, wire exit, bend radius and manufacturing tolerance.

How does THOR-403542 compare with nearby 34 × 42mm alternatives?

THOR-303442↗ is a thinner 3 × 34 × 42mm, 350mAh option, while THOR-403442↗ uses a closely matched 4 × 34 × 42mm format at 700mAh. THOR-403542 keeps a 4mm profile with a slightly wider 35mm nominal cell and 550mAh capacity.

Which alternatives suit a narrower but longer battery cavity?

THOR-383046↗ uses a 3.8 × 30 × 46mm, 500mAh format, while THOR-403048↗ uses a 4 × 30 × 48mm, 500mAh format. These trade the 35 × 42mm near-square footprint for a 30mm-wide, longer geometry.

What must be confirmed before using THOR-403542 in a tracker or wearable monitor?

Confirm continuous and peak current requirements, radio duty cycle, charging profile, PCM limits, connector family and polarity, wire gauge and length, optional NTC, final pack dimensions, antenna clearance, operating temperature and measured runtime in the actual device.

Stable 3.7 V nominal output for reliable power delivery
Long cycle life — typically several hundred cycles, cost-efficient
Built-in protection: overcharge, over-discharge, short-circuit
Custom size, capacity, connector & PCM/BMS
UN38.3 / MSDS ready; CE, KC, ROHS on request

Why Choose THOR Power

A vertically integrated lithium battery manufacturer (Dengzhou Xinju New Energy) with the scale and engineering depth to deliver custom LiPo cells reliably at volume.

3 factories, 800+ staff

Source-manufacturer scale — not a trading company.

200+ engineers

R&D led by a chief battery scientist for rapid custom design.

60,000 pouch cells / day

High-volume manufacturing with products exported across the US, Europe, Japan & Korea, SE Asia, Latin America and Africa.

End-to-end quality control

From raw material to finished cell.

Factory Photos

Automation Equipment

Testing Equipment

Warehouse & Certifications

Model	THOR-403542
Battery Type	Lithium Polymer (LiPo) pouch cell
Capacity	550 mAh
Certifications	UN38.3 / MSDS (IEC 62133-2, CE, KC on request)
MOQ	From 10 pcs for samples; production quoted per project
Customization	Size, capacity, connector, wire length, PCM/BMS, NTC, label

THOR-403542 3.7V 550mAh LiPo Battery – 4×35×42mm

The THOR-403542 is a 1S 3.7V 550mAh lithium polymer (LiPo) battery built around a 4 × 35 × 42mm nominal bare pouch cell. Its thin 4mm profile and compact, near-square footprint suit compact GPS trackers, smart ID badges, personal safety pendants, and wearable environmental monitors where enclosure depth is limited. With the standard PCM arrangement, the finished size is approximately 4.0 × 35 × 44mm; final pack dimensions depend on the selected PCM, connector, wire routing, and insulation. PCM, connector type, polarity, wire length, optional NTC, and labeling can be customized for OEM projects.

Wholesale Pricing (USD)

Order Quantity	Reference Unit Price
10 – 99 pcs	$2.80 / pc
100 – 999 pcs	$2.30 / pc
1,000 – 9,999 pcs	$2.00 / pc
10,000+ pcs	Contact for best price

Reference pricing is shown above. Talk to a Battery Engineer for a project-specific quotation.

Reference unit pricing shown above is for standard configuration only. Final pricing may vary by cell configuration, connector, wire length, PCM/BMS, labeling, packaging, certification requirements and order quantity. Shipping cost is not included. MOQ: from 10 pcs for samples; production quantities are quoted per project.

Get an Engineering Quote

Custom sizes, capacities, connectors & PCM/BMS available. MOQ-friendly. Samples in days.

Battery Specification — THOR-403542

Mechanical Characteristics

Model	THOR-403542
Cell Type	Lithium Polymer (LiPo) pouch cell
Configuration	1S1P (customizable)
Dimensions (T×W×L)	4 × 35 × 42 mm (bare cell)
Dimension Tolerance	Thickness ±0.2 mm; Width/Length ±0.5 mm
With PCM Board	Length approx. +2 mm vs bare cell
Weight	Approx. 12 g
PCM / BMS	Included (standard)
NTC Thermistor	Optional
Connector	PH2.0 / Molex 1.25 (custom available)
Wire Length	Customizable
UN38.3	Test Summary available
Safety Data Sheet	SDS / MSDS available
IEC 62133-2	Available for selected models
RoHS / REACH	Compliance documents available

Electrical Specifications

Nominal Voltage	3.7 V
Rated Capacity	550 mAh
Energy	2.04 Wh
Charge Voltage	4.20 ± 0.03 V
Standard Charge	110 mA (0.2C), CC/CV to 4.20 V
Charge Cut-off Current	0.02C
Max. Charge Current	550 mA (up to 1C), model-specific
Discharge Cut-off Voltage	3.0 V
Standard Discharge	110 mA (0.2C)
Max. Continuous Discharge	550 mA (1C), model-specific
Internal Resistance	≤ 100 mΩ (1 kHz, 50% SOC, 25℃)
Cycle Life	≥ 500 cycles, ≥ 80% capacity
Cycle Test Condition	0.5C charge / 0.5C discharge, 3.0-4.2 V, 25 ± 2℃
Charge Temperature	0℃ ~ 45℃
Discharge Temperature	-20℃ ~ 60℃
Storage Temperature	-10℃ ~ 45℃ (≤ 1 month)
Capacity Retention	≥ 90% after 28 days @ 25℃
Note	Higher discharge-rate designs available upon engineering review

Protection Circuit (when PCM equipped)

Overcharge Detection	4.28 ± 0.03 V per cell
Overcharge Release	4.08 ± 0.05 V
Over-discharge Detection	2.75 ± 0.05 V
Over-discharge Release	3.00 ± 0.05 V
Overcurrent Protection	Per PCM design (2A ~ 5A typical)
Short-circuit Protection	Yes, auto-recovery

Values shown are THOR Power standard specifications for this cell class. Final parameters are confirmed in the engineering datasheet for your configuration.

Typical Applications — THOR-403542

Compact GPS Trackers — PrimaryThe thin 4mm profile and compact 35 × 42mm footprint make this 550mAh LiPo battery a technical-fit option for compact GPS and asset-tracking designs where battery depth is limited. Confirm GNSS, cellular and radio-transmit peak-current requirements before approving samples.

Smart ID BadgesA technical-fit option for rechargeable smart ID badges using BLE, displays or periodic scanning when the enclosure can accept the near-square 35 × 42mm footprint. Validate standby draw, radio peaks and required service interval.

Personal Safety PendantsThe shallow, near-square geometry can suit personal safety pendants and wearable alert devices. Confirm the finished pack envelope, antenna clearance, connector polarity, charging method and emergency-transmit load.

Wearable Air-Quality & Environmental MonitorsSuitable for evaluation in wearable environmental sensing devices that can accommodate the shallow footprint. Confirm sensor duty cycle, wireless activity, operating temperature, charging profile and target runtime before cell approval.