How Do I Replace a Fuse?

Replacement background: When the SUN2000 is faulty, the Battery fuse is likely to be damaged. In this case, check whether the fuse is open-circuited and replace it.

  • Step 1

    Power off the system. For details, see System Power-Off.
    After the system is powered off, the remaining electricity and heat still exist in the chassis, which may cause electric shocks or burns. Therefore, you need to wear protective gloves and perform operations 5 minutes after the system is powered off.

  • Step 2 Loosen the screws on the fuse shell.

    Figure 1-1 Removing the screw shell

  • Step 3 Lift the fuse box opening, remove the fuse, insert a new fuse into the slot, and close the fuse box. If you hear a click sound and the bulge on the side is inside the box, the fuse box is properly installed.

    Figure 1-2 Replacing a fuse

  • Fuse Specifications

    Table 1-1 Fuse specifications

    Fuse Required Specifications
    Type Lower Limit Typical Value Upper Limit
    Component type - Fuse -
    Fuse type - Fast blow fuse -
    Rated voltage (V AC&V DC) 1100VDC - -
    Rated current 32 A - -
    Breaking capacity 10 kA - -
    Nominal fusing heat I2T 600 - 1000
    Cold resistance value - - 0.005 Ω
    Package dimensions (the dimension tolerance should be specified in the specifications provided by the supplier) - 14 mm x 51 mm -

    Table 1-2 Fuse model

    Number Fuse model Manufacture
    1 FWL-32A14F Cooper Xi'an Fusegear Co., Ltd
    2 VC14-32A1100VDCAR VICFUSE
    3 RS309-MM-14C32A Xi'an Sinofuse Electric Co., Ltd

1.2 SOC Change Description

1. How does the SOC change from 99% to 100% when the battery is about to be fully charged?

When the SOC is greater than 99%, the battery switches to float charging and the charging current decreases gradually. Finally, the SOC reaches 100%.

2. When the battery temperature is low, the charging power is displayed as about 300 W, but the SOC does not change. Why?

When the internal temperature of the battery module is low, the internal heating component starts to heat the battery. The heating power is 300 W (typical value). When the heating component is working, the battery is not charged and the SOC does not change. Battery heating helps to keep the cell at a proper operating temperature and prolong the service life of the product.

1.3 Checking Cable Connection when the Battery Fails to Be Upgraded

If the battery fails to be upgraded, check the cable connections by referring to Electrical Connection. If the upgrade fails, reconnect the cables correctly and perform the upgrade again.

1.4 Delayed Upgrade Description

After logging in to the inverter, if the FusionSolar app detects that the LUNA2000 firmware version is outdated, the app prompts you to upgrade the LUNA2000. You can choose immediate activation or delayed activation. If you choose immediate activation, the LUNA will be upgraded immediately after the firmware package is uploaded. The upgrade process takes approximately 30 minutes. If you choose delayed activation, the activation of the firmware will be performed four hours after you log out of the app.

1.5 How Do I Recycle Used Batteries?


  1. The Company does not recycle batteries. Contact local recycling agencies to handle batteries.
  2. If there are no such agencies in your area, you can contact the nearest foreign recycling agencies.
  • Step 1 Contact the nearest recycling agency.
  • Step 2 Recycling agencies assess the costs.
  • Step 3 Recycling agencies carry out recycling, which can be done in two ways:
    • Onsite recycling: Recycling agencies can visit your sites to recycle lithium batteries, but the price depends on actual conditions such as the distance and transportation expenses.
    • Centralized recycling: You can collect all lithium batteries to be recycled in one place for the recycling agencies to handle.


    You need to cover the related transportation expenses.

  • Step 4Recycling companies handle recycling. The recycled lithium batteries are at the disposal of the recycling companies.