RTC battery HP EliteBook 755 G5 840 G5 846 G5 L17255-001

The HP L17255-001 RTC battery is a replacement real-time clock battery designed for HP EliteBook 755 G5, 840 G5 and 846 G5 laptops. It preserves system time, BIOS settings and hardware configuration when the main battery is removed or the device is powered off for extended periods. The part is intended as a direct-fit spare to restore RTC function and prevent time-related errors, BIOS reset prompts, or loss of custom system settings.

Advantages

This RTC battery offers straightforward compatibility with the specified EliteBook models and is engineered for stable timekeeping and low self-discharge. Its compact form factor allows unobtrusive installation on the system board while delivering consistent voltage to backup the real-time clock and CMOS memory. The battery helps avoid BIOS resets and the need to reconfigure system parameters after power loss.

Suitable for

• Repairing or maintaining HP EliteBook 755 G5, 840 G5 and 846 G5 laptops
• Replacing a depleted or failing RTC/CMOS battery to restore correct system time
• Servicing devices that display BIOS time errors or reset BIOS settings on power-off
• IT maintenance kits for fleet laptops or spare-parts inventory

Key specifications

• Function: Real-time clock (RTC) backup and CMOS memory power
• Form factor: Small coin-style backup battery with connector suited for internal motherboard mounting
• Voltage: Designed to provide stable backup voltage suitable for RTC circuitry
• Compatibility: Specifically matched to certain HP EliteBook G5 series models
• Durability: Low self-discharge chemical construction for long shelf and service life

How to use

Power off the laptop and disconnect any external power source and main battery before accessing the internal components. Open the service access panel or remove the bottom cover following the manufacturer’s maintenance instructions for the relevant EliteBook model. Locate the existing RTC/CMOS battery on the motherboard and carefully disconnect it from its socket or clip. Install the replacement battery in the same orientation and reconnect any retained cable or holder. Reassemble the laptop, reconnect power, and enter BIOS to verify date, time and saved settings. Dispose of the old battery in accordance with local battery recycling regulations.

Recommendations

Use only when compatible with the listed EliteBook models. If unsure about disassembly, consult official service documentation or an authorized technician. Verify BIOS settings after replacement and keep a record of the installation date to monitor battery life.