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MS621R-II27E
MS621R-II27E
| Part Number | MS621R-II27E |
|---|---|
| Manufacturer | Seiko Instruments (SII) |
| Category | Batteries & Power Products > Rechargeable Batteries (Secondary) – Coin / Button Cell |
| Description | Rechargeable Manganese Silicon Lithium Coin Cell Battery with SMT Tab Terminals, 3.0V Nominal Voltage, 3.0mAh Capacity, 621 Package, Surface Mount / PCB Tab Configuration, Extended Operating Temperature Range (-20°C to +60°C). |
| Stock Status | In Stock |
| Origin | Original Factory |
Product Overview
The MS621R-II27E is a rechargeable manganese silicon lithium coin cell made by Seiko Instruments (SII). Equipped with factory-welded II27E SMT tabs for automated assembly and reflow soldering, this 3.0V secondary battery offers reliable long-term memory backup. With compact 621 dimensions (6.8 mm × 2.1 mm) and 3.0mAh capacity, it features stable discharge voltage and low internal resistance. It serves RTC, SRAM/Flash, low-power MCU and IoT modules for power retention when main power cuts off.
Core Advantages
Compact 6.8mm Size with 3.0mAh Capacity
Adopts Seiko Manganese Silicon Lithium chemistry, delivering stable backup power within small 6.8 mm × 2.1 mm dimension for compact electronic equipment.
Stable 3.0V Nominal Output
Provides flat 3.0V discharge curve, directly supplying RTC chips, SRAM and low-power microcontrollers without extra voltage regulation circuits.
Good Overcharge Resistance & Cycle Stability
Designed for long-term trickle charging scenarios, with outstanding overcharge tolerance and stable charge-discharge cycle life for maintenance-free operation.
Customized II27E SMT Tab Terminals
Factory welded II27E surface mount tabs support high-speed automated PCB assembly and ensure stable soldering on high-density circuit boards.
Key Specifications
| Brand | Seiko Instruments (SII) |
|---|---|
| Part Number | MS621R-II27E |
| RoHS Status | RoHS Compliant / Lead-Free / Mercury-Free |
| Warranty | 1-Year Standard Quality Warranty |
| Package / Case | Coin Cell 621 (6.8 mm Diameter × 2.1 mm Height) |
| Mounting Type | PCB Mount / Surface Mount (SMT Tab Terminal II27E) |
| Surface Marking / Silkscreen | SII MS621R Marking |
| Battery Chemistry | Rechargeable Manganese Silicon Lithium |
| Nominal Voltage | 3.0 V |
| Operating Voltage Range | 2.0 V ~ 3.3 V |
| Nominal Capacity | 3.0 mAh |
| Standard Charge Voltage | 2.8V to 3.3V (Recommended 3.1V ± 0.15V) |
| Standard Charge Current | 0.01 mA |
| Cycle Life | ≥200 cycles (99% DOD); ≥1000 cycles (20% DOD) |
| Reflow Solderable | Supported |
| Operating Temperature Range | -20°C to +60°C |
| Weight | Approx. 0.23 g |
| Packaging Format | Tape & Reel / Tray / Bulk |
Precautions
- Strictly Control Charging Voltage: Charge within 3.1V ± 0.15V. Continuous voltage over 3.3V will reduce capacity and damage electrolyte.
- Follow Standard Reflow Profiles: Comply with Seiko recommended reflow parameters to prevent thermal damage to internal seals.
- Forbid Direct Heating on Cell: Only solder through II27E tabs. Direct heating of battery shell destroys sealing structure.
- Avoid Reverse Charging & Short Circuit: Ensure correct PCB polarity. Short circuit leads to high current discharge and cell failure.
- Safe Disposal Requirements: Do not incinerate, disassemble or crush. Handle waste battery following local lithium battery regulations.
Typical Applications
- Real-Time Clock (RTC) power backup in smartphones, tablets, smartwatches, and wearable tech
- SRAM, NVRAM, and flash memory data retention in industrial controllers, smart meters, and POS systems
- Backup power source for wireless IoT sensor nodes, security devices, and asset trackers
- Digital cameras, portable healthcare monitors, handheld terminals, and audio devices
- Automotive dashcams, electronic toll collection (ETC) units, and key fobs
Order & Shipping Info
| Minimum Order Quantity (MOQ) | 1 Piece |
|---|---|
| Shipping Time | Shipped within 1-2 business days |
| Delivery Time | 3-7 working days worldwide |
| Shipping Methods | DHL, UPS, FedEx, EMS, YFH Standard |
| Payment Methods | T/T (Bank Transfer), PayPal, Credit Card, Western Union |
Technical Support
For datasheet, sample requests, stock check, bulk pricing and custom versions with solder tabs, pins and wire assemblies, please use the Quick Inquiry form. We will reply within 24 hours.
Frequently Asked Questions
Q1: Is the Seiko MS621R-II27E rechargeable or primary battery?
A: MS621R-II27E is a rechargeable manganese silicon lithium secondary cell, engineered for long-term trickle charging and RTC/memory backup circuits.
Q2: What does the suffix “II27E” mean?
A: II27E defines the factory pre-welded SMT tab specification, including tab shape, height and mounting direction to support automated PCB assembly.
Q3: How does MS621R differ from ML621 coin cells?
A: Both share identical 6.8×2.1mm dimensions. MS621R supports continuous trickle charging with better cycle stability, while ML621 is mainly for non-rechargeable applications.
Q4: Are alternative or compatible replacement models available?
A: Equivalent SMT tab-type rechargeable backup cells can be used, but verify charging voltage limits, cell thickness and tab position. Direct substitution without electrical validation is not recommended.
Q5: Can I use this battery without following the trickle charge limits?
A: No. Do not exceed the maximum charging voltage of 3.3V. Overvoltage will cause capacity attenuation and shorten service life significantly.
Q6: Can the battery tabs be manually re-soldered?
A: We do not recommend soldering directly to the cell casing. Only heat the II27E solder tabs and avoid prolonged high temperature to prevent internal sealing failure.
Q7: Can custom tab layouts and wire lead versions be supplied?
A: Yes. Besides II27E tabs, multiple solder tab forms and pin lead assemblies are available to match different PCB layouts for bulk orders.
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