MG HS Battery Replacement: Upgrading to Houny LN2 LiFePO4
| Item | Details |
|---|---|
| Applicable Model | MG HS 1.5T Gasoline Version |
| Upgrade Brand | Houny Battery |
| Battery Model | H585LT2 85Ah (LN2 Size) |
Background & Selection
A few years ago, we upgraded our imported family car to a GreenRun LiFePO4 battery, and both the user experience and lifespan have been highly satisfactory. Recently, a fellow HS 1.5T owner noticed their original battery was degrading, with internal resistance gradually rising. After some research, they also decided to make the switch to a LiFePO4 (Lithium Iron Phosphate) battery.
The original HS battery is a Sail 6-QW-63MG, which falls under the LN2 size specification. While the HS battery tray can accommodate a larger LN3 size, switching to LN3 would mean the original thermal insulation sleeve could no longer be used. Therefore, we decided to stick with the LN2 size.
In Taiwan, the LN2 size faces the same issue as Japanese B24 and D23 sizes: limited LiFePO4 options on the market. Most products come from independent workshops or lack factory information. While there are many 12V LiFePO4 brands in the Chinese market, some are often criticized for exaggerating capacity and poor build quality. After careful comparison, we ultimately chose Houny, a manufacturer deeply rooted in LiFePO4 starter batteries that provides OEM/ODM lithium battery solutions for European and American brands.
Following Houny’s 2025 product line revamp, their offerings are divided into Gold, Blue, and Green series. We purchased the 85Ah Gold series. There is also a 100Ah option in the same LN2 size, but considering the owner’s HS is completely stock, used only as a weekend car, and has no heavy electrical modifications—plus the fact that LiFePO4 has a deeper Depth of Discharge (DoD), making its usable capacity 1.6 times that of lead-acid—the 85Ah LiFePO4 actually provides usable power equivalent to a 130Ah lead-acid battery, which is more than enough.
Unboxing Details
Outer Packaging
Side Specification Labels
Top Battery Label
Front Battery Parameters
Ventilation Hole Detail
Pure Copper Terminal Detail
Voltage and Internal Resistance upon Arrival
Installation Process
Tools Required
| Tool Name | Purpose & Notes |
|---|---|
| 10mm L-Socket | Essential for removing the battery base bracket bolts and positive/negative terminals. |
| OBD Memory Saver | Used for uninterrupted replacement to prevent loss of ECU and audio settings. |
| Jumper Power Supply | Any 12V battery or jump starter power bank to supply power to the OBD Memory Saver. |
| Battery Handle | Assists in lifting (the original battery has no handle; highly recommended to save effort). |
Installation Steps
The following is a record of the actual operational process. No fault codes appeared after the installation was complete.
| Step | Action | Notes & Details |
|---|---|---|
| 1 | Connect Memory Saver | Connect the jumper power supply to the OBD Memory Saver, and plug it into the car’s OBD port. |
| 2 | Vehicle Sleep | Close all doors and wait 5 minutes to allow the vehicle’s computer to enter a full sleep state. |
| 3 | Remove Base Bracket | Use the 10mm socket to loosen the battery base fixing bolt, then remove the bolt and the hold-down plate. |
| 4 | Create Operating Space | Push the old battery towards the front of the car to disengage it from the tabs. This creates more space around the positive terminal for easier operation. |
| 5 | Disconnect Terminals | Loosen the Negative terminal first, followed by the Positive terminal. |
| 6 | Swap Batteries | Attach the battery handle to lift out the old battery, and place the new LiFePO4 battery in. |
| 7 | Reconnect Terminals | Secure the Positive terminal first, followed by the Negative terminal. |
| 8 | Secure New Battery | Push the new battery towards the driver’s side to ensure it locks tightly into the base’s fixing tabs. |
| 9 | Lock Base Bracket | Reinstall and securely tighten the hold-down plate and bolt. |
| 10 | Complete Installation | Remove the OBD memory saver and start the vehicle to confirm everything is normal. |
Completion & Review
The actual installation took about 15 minutes. The MG HS 1.5T has plenty of space in the engine bay, making it a very easy vehicle for a battery swap.
The fellow owner decided to upgrade to a LiFePO4 battery primarily due to the following core advantages:
| Advantage | Detailed Explanation | Expected Benefit |
|---|---|---|
| Charge/Discharge Performance | High charging efficiency effectively reduces engine load; fast discharge response stabilizes the electrical system. | Extends the life of the car’s alternator and improves idle quality. |
| Environmental Adaptability | Features high and low-temperature stability, with a safe lithium iron phosphate structure. | Heat-resistant with no risk of combustion, enhancing engine bay electrical safety. |
| Physical Characteristics | Weight reduced by approx. 50% (Original is ~17kg, LiFePO4 is only 8kg), with an extremely low self-discharge rate. | Lightweighting improves handling slightly; the extremely low self-discharge rate is perfect for weekend cars. |
| Fuel Economy Validation | High charging efficiency reduces energy waste; the time the alternator needs to run to charge is significantly shortened. | According to research, replacing the battery can substantively optimize the vehicle’s fuel economy. |
