During routine maintenance of the lithium battery cabinet, which of the following areas should be protected from electric shocks caused by exposed hands or metal objects?

All the listed components are energized parts of the high-voltage DC circuit within a lithium battery cabinet and present a severe electric shock hazard. During maintenance, it is imperative to protect against accidental contact with any of these points. A & E (Battery general positive/negative terminal): These are the main output terminals of the entire battery bank, carrying the full system voltage and capable of delivering lethal current. B & D (Battery negative/positive terminal): These refer to the terminals on individual battery modules. Even a single module operates at a hazardous voltage level (typically ~48VDC, but can be higher). C (Short-circuit copper bar between battery modules): These busbars connect the modules in series or parallel and are always live when the system is operational. They carry the same voltage and current potential as the battery terminals they connect. Therefore, any maintenance activity requires proper lockout/tagout procedures, the use of insulated tools, and appropriate Personal Protective Equipment (PPE) to prevent contact with any of these exposed conductive parts.

This is a multiple-answer question where all options are correct. There are no incorrect options. Selecting only some of the options would be wrong because it would imply that the unselected terminals or busbars are safe to touch, which is dangerously false. All energized terminals and conductors in a battery system must be treated as hazardous.

Huawei Technologies Co., Ltd. (2022). SmartLi 2.0 Battery Energy Storage System V100R022C10 User Manual. Chapter 2 "Safety Precautions", Section "Electrical Safety". This section explicitly warns: "Before touching any conductors in the battery cabinet, use a multimeter to measure the voltage to ensure that the conductors are de-energized" and lists terminals and busbars as hazardous points.

IEEE Std 1679-2018, IEEE Guide for the Characterization and Evaluation of Lithium-Based Batteries in Stationary Applications. Section 5.3 "Safety Considerations". This standard outlines the inherent electrical hazards of battery systems, including shock from exposed terminals and busbars, and specifies requirements for protective measures.

Stanford University, SLAC National Accelerator Laboratory. (2021). ES&H Manual, Chapter 41: Battery Safety Program. Section 4.0 "Hazards". This document identifies electric shock from battery terminals and inter-cell connectors (busbars) as a primary hazard requiring stringent controls.