Changan Eado EV Traction Battery Assembly Removal and Installation Guide

Fault Background

The traction battery assembly removal and installation for the Changan Eado EV follows a two-level process: pack-level + stack-level. Pack-level removal starts with removing the safety switch under the driver's seat, using a lift and a lifting platform cart (capacity 450 kg, table 1500×900) plus a hydraulic cart in a three-point coordination. First loosen all fixing bolts, then remove the 4 bolts at the front and rear ends before removing the left and right sides. Stack-level removal proceeds in a 24-step sequence: "upper cover → busbar → high-voltage electrical box → current sensor → controller → relay → module". Among these, bolts connected to modules are single-use and must be replaced after removal, upper cover plate fixing bolts must be replaced after removal, and modules are non-serviceable components and must not be disassembled. Nine safety rules apply throughout (training, fire extinguisher/fire sand, disconnect safety switch, insulating gloves, single-person operation with an attendant, insulating tape for exposed busbars). This article is compiled as a service guide.

Service Safety Precautions (9 Rules)

1. Operators must have completed safety removal/installation training and passed the test;
2. The service environment must be dry and clean;
3. The service environment must be equipped with dry powder fire extinguishers, fire sand, and other safety tools; the disassembly workbench must be insulated;
4. Lifts or lifting platform carts must be fault-free and operated by qualified personnel;
5. High voltage of the traction battery assembly must be cut off before removal (disconnect the safety switch);
6. Wear insulating gloves throughout; do not wear metal objects or have obvious water on your body;
7. No more than two people may perform removal/installation simultaneously; another person must accompany to handle emergencies;
8. Special tools must be insulated with insulating tape;
9. Do not place parts or tools directly on the traction battery assembly; immediately insulate exposed busbars, removed modules/cells/busbars with insulating tape; do not allow small parts or fasteners to fall into the battery assembly.

Special Tools and Equipment

Battery Pack Removal Procedure (4.1)

1. Remove the safety switch from under the driver's seat;
2. Raise the vehicle to a certain height using a lift;
3. Raise the lifting platform cart and support the bottom of the battery pack;
4. Use a hydraulic cart to support the lower surface of the battery—the cart should be as close to the rear of the battery as possible, and the battery should be symmetrically positioned left-right on the cart;
5. Disconnect the front and rear connectors of the battery pack;
6. Remove the battery fixing bolts—first loosen all bolts, then remove the 4 bolts at the front and rear ends of the battery, then remove the left and right sides.

Battery Pack Stack Component Removal Procedure (4.2 · 24 Steps)

1. Remove the traction battery upper cover: Remove the 4 safety switch fixing bolts + the 40 fixing bolts of the battery upper cover plate + 2 limit bolts → remove the upper cover (upper cover plate fixing bolts must be replaced after removal).

Steps 2–4. Busbars and current sensor: Remove busbars (high-voltage electrical box adapter) → remove internal busbars of the high-voltage box (output positive / output negative / charge positive)—bolts connected to modules are single-use and must not be reused; replace with new nuts → remove the current sensor assembly (main)—first remove the busbar (main current sensor) 2101310-BN71, then remove the 2 screws and connector on the sensor.

Steps 5–7. High-voltage electrical box family: Remove the battery high-voltage electrical box → remove the base—operate per "high-voltage box removal" requirements, remove the busbar insulation cover and busbar fastening bolts, remove the safety switch bracket bolts, disconnect connectors → remove the 2 bolts of the busbar shown and the 4 bolts of the safety switch socket and take it off.

Steps 8–9. Controller and busbars: Remove the battery status management controller assembly—first remove the external bolts in sequence, and finally disconnect the connector to remove the controller → remove busbars ×2—remove the insulation cover and remove the busbar fastening bolts (single-use bolts must be replaced).

Steps 10–12. High-voltage connectors and upper/lower layers: Remove the high-voltage connector assembly—disconnect the high-voltage connector and the high-voltage interlock connector of the charging input wiring harness assembly → remove the upper layer busbar fastening bolts and connectors → remove the upper layer battery fixing bolts and take out the product → per busbar removal requirements, remove all lower layer busbar fastening bolts → remove all lower layer traction battery fixing bolts and take out the product.

Steps 13–15. BMS and relay family: Remove the battery status management controller assembly—disconnect the connector connected to the BMS, remove the 4 BMS fixing bolts and take it off → remove the high-voltage box main/sub-box busbars (charge positive relay positive terminal adapter, main negative relay positive terminal, main positive relay positive terminal, main negative relay negative terminal) → remove the relay assembly (main), relay assembly (precharge), resistor assembly (precharge)—disconnect the signal acquisition wiring harness connector, remove the fixing bolts.

Steps 16–17. Final steps: Remove the busbar (charge positive relay negative terminal adapter) → Module removal procedure: the module is a single component and must not be disassembled.

Installation Procedure (5.1)

Perform the reverse order of the "battery pack and stack component removal procedure"—replace all single-use fasteners such as module-connected bolts and upper cover plate fixing bolts with new ones, then tighten to the specified torque.

Key Parameter Quick Reference

Safety Warning

• This article is for technical reference. Traction battery removal/installation is high-voltage work and must be performed by personnel who have completed safety removal/installation training and passed the test.
• Cut off high voltage (disconnect the safety switch) before removal; wear insulating gloves throughout; no more than two people may perform removal/installation simultaneously, and an attendant must be present.
• Fire extinguisher, fire sand, insulated workbench, and tool insulation with tape—all four are indispensable.
• Modules are non-serviceable components; disassembly for repair is prohibited.

Service Insights

The most valuable aspects of this removal/installation manual are the "single-use and sequence" disciplines: bolts connected to modules and upper cover plate fixing bolts must be replaced after removal—these are fasteners for crimped high-voltage contact surfaces; if reused, preload is insufficient, and increased contact resistance is the starting point for heat generation and insulation degradation. Battery fixing bolts: first loosen all, then remove the 4 front/rear bolts before the sides—this prevents the battery pack from "seesaw" stress on the last two bolts, avoiding deformation of the housing and body mounting points. The 24-step sequence within the stack is essentially a voltage-decreasing tree: upper cover → adapter busbars → high-voltage box internal busbars (positive/negative/charge positive) → current sensor → high-voltage electrical box → controller → upper/lower layer busbars and battery—each layer removed exposes components of a lower voltage level, removing peripheral adapters first and then the main circuit minimizes "live work". Three on-site details worth remembering: the hydraulic cart supporting the battery should be near the rear and symmetrically positioned (center of gravity!); when removing the controller, remove bolts first, then the connector (cut power before signal); modules are non-serviceable—the service boundary of the battery pack ends at the module level; cell-level issues are addressed by module replacement, not disassembly.

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【This article is for reference only】