MAX745 1-4 Pack Lithium Battery Charging Board

The MAX745 is a highly integrated lithium-ion and lithium-polymer battery charger IC that supports charging 1 to 4 series cells with precision current and voltage regulation. Electronics engineers, roboticists, and IoT developers rely on this board for reliable power management in portable devices, drones, and wearable applications. This charging solution eliminates the complexity of designing discrete charging circuits by providing built-in protection against overcharge, overdischarge, and thermal runaway conditions.

Product Overview

The MAX745 charging board operates on the principle of constant-current constant-voltage (CC-CV) charging topology, which optimizes battery lifespan and charging speed simultaneously. The IC monitors cell voltage in real-time and transitions from constant current mode to constant voltage mode when the battery reaches approximately 4.2V per cell, ensuring safe and efficient charging. The board features integrated MOSFET switches for charge path control and thermistor input for temperature-compensated charging, preventing damage to lithium cells during extreme temperature conditions.

This 1-4 pack configuration allows flexible cell count selection through simple pin configuration or jumper settings, making it ideal for both single-cell applications like smartwatches and four-cell battery packs for power tools or RC vehicles. The MAX745 delivers up to 1A charging current with minimal external component requirements, reducing PCB footprint and design complexity. Built-in safety features include charge termination when current drops below threshold, automatic recharge capability, and fault detection for shorted or missing batteries.

Key Specifications

Specification	Details
Product Type	Lithium Battery Charging Board with MAX745 IC
Brand	Maxim Integrated
Origin	Original/Authentic
Warranty	7 days on manufacturing defects
Shipping	1-5 days from Bengaluru
Delivery	7-8 days across India
Support	24/7 via Email and WhatsApp
Input Voltage Range	4.5V to 16V DC
Charging Current	Up to 1000mA adjustable
Cell Configuration	1 to 4 Series Lithium Cells
Termination Voltage	4.2V per cell (adjustable)
Temperature Range	0°C to 45°C operating
PCB Dimensions	Compact form factor with standard connectors

Key Features

• Programmable 1-4 cell configuration allowing single board deployment across multiple battery pack designs without redesign
• Integrated current limiting and thermal shutdown protecting against overcurrent damage and thermal runaway scenarios
• Automatic recharge function that monitors battery voltage and resumes charging if voltage drops below threshold during storage
• Low external component count with integrated power MOSFET reducing design complexity and improving reliability
• Thermistor input for temperature-compensated charging extending lithium cell lifespan in variable climate conditions
• Status output pins indicating charging state, allowing microcontroller integration for smart charging applications

Applications and Use Cases

• Portable consumer electronics including smartphones, tablets, and power banks requiring single-cell fast charging with thermal management
• Drone and RC vehicle battery management systems where multi-cell packs demand synchronized charging with cell balancing capabilities
• Wearable devices and IoT sensors utilizing single-cell lithium batteries with extended runtime and minimal charging infrastructure
• Industrial handheld tools and emergency backup power systems requiring robust 3-4 cell pack charging with fault detection
• Solar-powered systems and renewable energy storage applications where the charger interfaces with variable input voltage sources
• Medical devices and portable diagnostic equipment demanding certified safety-compliant charging with automatic shutdown features

How to Use

Begin by configuring the MAX745 board for your target cell count using the onboard jumpers or solder bridges typically labeled for 1S, 2S, 3S, or 4S configurations. Connect your lithium battery pack to the designated battery connector ensuring correct polarity, and attach your DC power supply to the input terminals. The board will automatically detect battery presence and initiate charging in constant-current mode, with the status LED indicating active charging state.

For optimal performance, connect a thermistor to the thermistor input if operating in variable temperature environments above 35°C or below 5°C. Adjust the charging current using the onboard potentiometer or resistor divider network to match your battery capacity and desired charge time. Monitor the charge complete indicator pin which transitions low when charging terminates at 4.2V per cell, signaling that the battery is fully charged and safe for device operation. Allow proper ventilation around the board during charging to ensure thermal dissipation, and avoid exposing the board to moisture or conductive debris.

Frequently Asked Questions

Can the MAX745 board charge different cell count batteries without modification?

Yes, the 1-4 pack configuration includes jumper settings or solder bridges that allow you to select between 1S, 2S, 3S, or 4S charging modes. Simply adjust the configuration jumpers before connecting your battery pack. This eliminates the need for multiple charging boards across different product lines.

What happens if I exceed the maximum 1A charging current rating?

The MAX745 includes integrated current limiting that prevents output current from exceeding the programmed threshold, protecting both the IC and your battery. However, sustained operation at maximum current generates heat. For charging currents above 500mA, ensure adequate PCB copper area and heat dissipation to maintain operating temperature below 45°C.

Is the MAX745 board suitable for fast charging applications?

The MAX745 supports up to 1A charging current, which qualifies as fast charging for single-cell batteries up to 2000mAh capacity. For larger capacity packs requiring 2A or higher, consider higher-current variants like MAX1555 or external current amplification circuits. The board is optimized for balanced charging speed and battery longevity rather than extreme fast charging.

How do I integrate the MAX745 charging board with a microcontroller for smart charging?

The MAX745 board provides status output pins that indicate charging state, charge complete, and fault conditions. Connect these pins to your microcontroller GPIO inputs to monitor charging progress. You can also control charging enable via the CHG pin, allowing your firmware to implement advanced power management strategies like charging schedule optimization or thermal throttling.

What is the typical charging time for a 2000mAh single-cell battery?

At maximum 1A charging current, a 2000mAh cell typically charges in approximately 2-2.5 hours accounting for the CC-CV transition. Actual charging time depends on battery internal resistance, temperature, and the programmed charge termination current threshold. Lower charging currents extend charging time but improve battery cycle life and reduce heat generation.

When will I receive my order?

Orders are dispatched within 1-5 business days from our Bengaluru warehouse. Delivery takes 7-8 days to most locations across India.

What is your return and warranty policy?

We offer a 7-day return policy on manufacturing defects only. Contact support within 7 days of receipt for free replacement or full refund. Not applicable for user damage or misuse.

Are bulk discounts available?

Yes, wholesale pricing for orders of 10 or more units. Contact our sales team via WhatsApp or email for a customized bulk quote.

Why Buy from The Engineer Store

• Genuine Products: Sourced directly from authorized distributors with authentication
• Expert Team: Our technical team validates every product before listing
• Fast Shipping: Dispatched within 1-5 days from our Bengaluru warehouse
• Pan-India Delivery: 7-8 days to Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata
• Payment Options: COD, UPI, credit/debit cards, net banking, EMI available
• Technical Support: 24/7 expert guidance via email and WhatsApp
• Returns: 7-day return policy on manufacturing defects only

Buy MAX745 1-4 Pack Lithium Battery Charging Board Online in India

Purchase the MAX745 1-4 Pack Lithium Battery Charging Board online at The Engineer Store, India's trusted source for genuine electronics. We deliver across Bengaluru, Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata, Ahmedabad, Jaipur, and Surat. Get the best price on MAX745 1-4 Pack Lithium Battery Charging Board with fast shipping and expert support.

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