Consumer Electronics Product StudiesMi PowerBank 3i Teardown and Costing

Mi-Power-12-Enclosure Design

Mi PowerBank 3i Teardown and Costing

Disclaimer

This study was conducted entirely in-house by ASI Engineering to demonstrate the capabilities of the xcPEP® platform. The product was independently procured by ASI. No proprietary or confidential information from any other party has been used. Results are not updated after publishing.

Teardown and Should Costing of Mi Power Bank 3i

This is Mi Power Bank 3i 20000 mAh, 18W with Fast Charging (PD)
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MI-Power-1-Exploded View
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Mi-Power-3-PCB-Layout
Prominent Features of Mi Power Bank 3i
A detailed teardown and benchmarking of the Mi Power Bank 3i 20000 mAh was conducted, mapping 10 features, specifications, and information at the product level. Some of the prominent features are detailed below:
Battery Cell in a Power Bank
The Mi Power Bank 3i houses two lithium-ion Polymer cells arranged in parallel configuration, providing multiple charge cycles for smartphones, tablets, and other devices. This design ensures reliable, long-lasting performance. The cells are encased in a compact plastic tray with the following attributes:
Mi-Power-6-Bank-Battery-Cell
Type:

Lithium-ion Polymer (High Density Batteries). The cells are rechargeable.

Capacity per Cell:

Each cell has a capacity of 10000 mAh and two cells are sandwiched to get 20000 mAh capacity

Configuration:

2P (Two cells in Parallel configuration). The cells are sandwiched together inside the power bank

Safety Features:

  • Built-in over-charge
  • Over-discharge
  • Thermal protection
Power Bank Circuit Protection Features
Safety is a cornerstone of the Mi Power Bank 3i. The device incorporates a twelve-layer circuit protection system, ensures maximum safety for both the power bank, and connected devices. The 12-layer circuit protection system that includes:
  • Over-current Protection
  • Over-charge and Over-discharge Protection
  • Short Circuit Protection
  • Temperature Protection
  • Reset mechanism for power recovery in abnormal conditions
Mi-Power-7-Bank-Circuit-Protection
Charging Technology used in Power Bank
The Mi Power Bank 3i offers dual input (Micro-USB and USB-C) and triple output (USB-A and USB-C), allowing simultaneous charging of three devices. With 18W fast charging, it delivers quick power to compatible devices, while the low-power mode ensures safe charging for delicate gadgets like fitness trackers, activated with a double-press of the power button.
Fast Charging:
Supports 18W fast charging with Power Delivery (PD) technology
Dual Input Ports:

Micro-USB and USB-C inputs for versatile charging

Dual Output Ports:

Two USB-A and one USB-C output ports supporting simultaneous charging.

Trickle Charging Mode:

Dedicated mode for low-power devices such as smartwatches and Bluetooth earbuds

Mi-Power-8-Bank-Ports-1
Mi-Power-9--Bank-Fast-Charging-Feature
Mi-Power-10-Bank-PCB-connection
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Mi Power Bank 3i Enclosure Design

Our teardown of the Mi Power Bank 3i reveals its meticulous internal design, highlighting high-quality components and advanced safety mechanisms. The Mi Power Bank 3i features a durable ABS plastic enclosure with a sleek matte finish for heat resistance and scratch protection. The components are securely assembled using Adhesive Padding and DSA (Double-Side Adhesive) for enhanced durability and a compact, seamless design ensures easy portability for on-the-go convenience.

Housing Material of Power Bank:

High-strength ABS (Acrylonitrile Butadiene Styrene) plastic for durability and heat resistance

Feel and Finish of Power Bank:

Matte finish for a premium feel and scratch resistance

Power Bank Dimensions and Weight:

150 x 72 x 26 mm, compact for portability and lightweight approximately 508 grams

Mi-Power-12-Enclosure Design
Mi-Power-13-Bank-Packaging

Bill of Materials (BOM) of Power Bank

We conducted a detailed teardown of the Mi Power Bank 20000mAh to study its components and system architecture. This teardown study involved analyzing data related to various part attributes, enabling a comprehensive understanding of its design and functionality.

Multi-level BOM (Bill of Materials) Structure of Power Bank
After teardown for this analysis, we used a Multi-level BOM (Bill of Materials) structure, which provides detailed insights into the main assemblies, their sub-assemblies, and individual components.
Summary of Assemblies and Components

The BOM (Bill of Materials) structure for the Mi Power Bank 20000mAh, with the number of assemblies and their child components, is summarized in the table below:

Mi-Power-14-Assemblies and-Components-Table
Mi-Power-15-Bank-No-of-Component-1
Mi-Power-16-PCB-BOM

Above image is of xcPEP BOM (Bill of Material) page view

Power Bank Teardown and Detailed BOM (Bill of Materials) Analysis
  • Total Assemblies and Components

    After teardown, 3 assemblies and 43 components were identified in the Mi Power Bank 20000mAh.

  • Component Parameters:
    Additionally, 40 BOM (Bill of Materials) parameters such as weight, dimensions, material type, electrical specifications, and thermal properties were mapped. On average, 20 parameters per part were recorded, depending on the complexity of the component.

Power Bank Weight Distribution Analysis

Weight Distribution Overview
Total Weight and Assembly Breakdown
The total weight of the Mi Power Bank 3i (including power bank, packaging, USB cable) is 508 grams. The weight distribution of the assemblies is as follows:

Power Bank: 85.86% (436 grams)

Packaging:12.18% (62 grams)

Accessories: 1.96% (10 grams)

Mi-Power-17-Assembly-weight-distribution

Teardown and Weight Contribution Insights

Major Components Weight Contribution
  • Rechargeable Polymer Cell: 73% (339.99 grams)
  • Bottom Cover: 10% (45.27 grams)
  • Packaging (Inner Box and Outer): 12.3% (57.4 grams)
  • Top Cover: 4.7% (22.09 grams)
Power Bank Weight Pareto Analysis

Pareto Analysis of Component Weight

Mi-Power-18-Weight-Pareto-Graph
Weight Pareto Insights from Teardown and Benchmarking of Power Bank
  1. The Rechargeable Polymer Cell is the heaviest component, weighing 339.99 grams (73% of the total weight).
  2. The Bottom Cover contributes 45.27 grams (10% of the total weight).
  3. Packaging materials (Inner Box and Outer Packaging) together weigh 57.4 grams (12.3% of total weight).
  4. The Top Cover is lightweight yet durable, weighing 22.09 grams (4.7% of total weight).

Power Bank Manufacturing Category Distribution Analysis

Analysis of Manufacturing Categories
After detailed teardown and analysis of Mi Power Bank 3i, we found inventory has components with different manufacturing categories and its distribution as follows:
Mi-Power-19-Bank-Manufacturing-Category
Overview of Manufacturing Category Distribution:
  • Mechanical Bought-Out Part (BOP): 33.33%
    Includes outsourced mechanical components essential for functionality.
  • Hard Consumables: 21.43%
    Covers adhesive pads, DSAs, and other consumable components.
  • Wiring Harness: 9.52%
    Essential for power distribution and communication.
  • Paper Packaging: 7.14%
  • Cell and PCB: 4.76%
  • Fabrication and Moulding: 12.9%

By integrating teardown insights, detailed analysis, and benchmarking observations, this comprehensive study underscores the Mi Power Bank 3i's optimized design and functionality.

Should Costing Analysis of Mi Power Bank 3i

Detailed Should Costing Breakdown

We recently purchased the Mi 20000 mAh power bank for ₹1,609, while it is currently listed on the Mi website for ₹1,891. Our estimated should-cost for the product is ₹1,436. Additionally, the same power bank was exported from India to Bhutan at ₹1,571 in the month of March 2024.

A detailed Should Costing of Mi Power Bank 3i was performed and the following are the outcomes of the study. The manufacturing cost of the power bank was found to be 1,436 INR and the following were the consideration for the study.

  1. The Power Bank was manufactured in Bangalore, India
  2. The volumes considered for the activity were 50,000 annually
  3. The latest Material rates and rates required for MHR calculations were taken for Q3 FY24-25
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Should Costing on xcPEP Platform:
Mi-Power-22-Bank-PCB-Costing

The above image shows should cost of PCB in xcPEP software

Power Bank Should Cost Breakdown

The total should-cost is distributed across the following assemblies:

  • Power Bank: 95.94% of total cost (INR 1377.88).
  • Packaging: 0.86% (INR 12.15).
  • Accessories: 3.20% (INR 46.09).
Mi-Power-23-Bank-Should-Cost-Breakdown
Power Bank Should Cost Pareto Analysis
Mi-Power-24-Bank-Should-Cost-Pareto-analysis-graph
Key Observations from the Power Bank Should Cost Pareto:

Based on the detailed breakdown of component should cost, following observations are made:

1. Power Bank PCB
  • The PCB contributes ₹779.32, accounting for 54% of the total cost. Its dominance in the should-cost breakdown highlights it as a critical focus area for cost optimization.
2. Rechargeable Polymer Cell Dominance
  • The Rechargeable Polymer Cell accounts for the highest cost at ₹527.09, making up 73% of the overall power bank cost.
  • Its weight and cost contribution highlight its role as a critical driver in the should costing process.
3. USB Cable
  • The USB Cable, with a cost of ₹46.09, represents 6.4% of the total cost, making it the second most expensive component in the analysis.
Observations from Should Costing of Mi Power Bank 3i:

Based on the detailed breakdown of component should cost, following observations are made:

1. Power Bank PCB
  • The top three components (PCB, Rechargeable Polymer Cell, and USB Cable) represent over 93% of the total cost, making them the primary focus for cost-saving measures.
  • Addressing these critical areas can provide substantial cost reductions, improving the overall profitability of the power bank.