XH-M602 vs XH-M603 vs XH-M604 — Which battery charging control module should you buy?

Introduction

The XH-M60x series of battery charging control modules are among the most popular and cost-effective solutions for managing 12V lead-acid and lithium-ion battery charging in DIY and embedded systems projects. All three modules — XH-M602, XH-M603, and XH-M604 — use a relay to automatically disconnect the charger when the battery reaches a set voltage, preventing overcharging. However, each model adds progressively more features. This guide breaks down the differences so you can choose the right module for your application.

XH-M602 — The Essentials

The XH-M602 is the base model. It monitors battery voltage via a potentiometer-adjustable threshold and triggers a relay to cut off the charger when the voltage is reached. LED indicators show power, charging, and full-charge status. It is the simplest and most affordable option, ideal for straightforward 12V lead-acid battery charging where you just need automatic cut-off without any display or timing features.

Best for: Basic overcharge protection, solar trickle charging, simple battery maintenance.

XH-M603 — Adding a Timer

The XH-M603 builds on the M602 by adding an adjustable timer function. In addition to voltage-based cut-off, you can set a maximum charging time. The charger disconnects when either the voltage threshold or the timer limit is reached — whichever comes first. This is particularly useful for lithium-ion battery packs where timed charging cycles are preferred, or in applications where you want to limit charging duration regardless of voltage.

Best for: Li-ion battery charging, timed charging cycles, applications requiring dual cut-off conditions.

XH-M604 — Digital Display and Dual Threshold

The XH-M604 is the most advanced module in the series. It adds a digital LED voltage display for real-time battery monitoring, and supports both an upper (charge cut-off) and lower (discharge/reconnect) voltage threshold. This means it can also protect against over-discharge by reconnecting the charger when the battery drops below the lower threshold. The digital display makes it easy to monitor battery state without any additional instrumentation.

Best for: Battery management systems requiring voltage monitoring, solar energy storage, UPS projects, applications needing both overcharge and over-discharge protection.

Comparison Table

Which One Should You Buy?

If you need a simple, reliable overcharge cut-off for a 12V lead-acid battery, the XH-M602 is sufficient and the most economical choice. If your application involves lithium-ion batteries or you want timed charging control, step up to the XH-M603. For any project requiring real-time voltage monitoring, over-discharge protection, or a more complete battery management solution, the XH-M604 is the clear choice.

All three modules are available at Embeded Studio with fast delivery across Pakistan: XH-M602 — XH-M603 — XH-M604.