This document serves as an assembly manual for the Sun Fun Kits V1 & V2 DIY battery kits, designed to guide users through the process of building their own battery packs. The kits are designed for quick and easy assembly, requiring only basic tools and a fundamental understanding of DC wiring.

Function Description

The Sun Fun Kits DIY battery kits allow users to assemble custom battery packs using prismatic cells. The manual specifically references EVE 280N type cells but notes compatibility with other manufacturers like CATL and RCPT. The core function of the kit is to provide the necessary components and instructions for creating a functional battery pack, including the enclosure, cell holders, battery management system (BMS), and wiring. The assembly process involves preparing the battery cells, installing them into the enclosure, wiring the cells in series, connecting the BMS, and finally securing the top plate and terminals.

Important Technical Specifications

The manual highlights several technical aspects and requirements for assembly:

Cell Type: The manual primarily uses EVE 280N type prismatic cells as an example, but the process is adaptable for other manufacturers' cells. Users are advised to select the correct cell type when purchasing their kit.
Tools Required:
- Hex driver set: 3mm, 4mm, 5mm, and 8mm
- Insulated drives for securing bolts
- Thread locking compound (e.g., blue Loctite)
- Kapton tape (1" to 2" in width)
- Double-sided sticky tape
- Velcro-style loop
- DC Voltmeter
- DC Power Supply: Capable of charging battery cells (3.65 volts, 20 Amps)
Optional Tools:
- Silicone sealer (for water resistance)
- Hot glue gun (for securing wires)
Bolt Specifications:
- M5 bolts and washers for the bottom bracket.
- 6mm bolts (8mm in length) for drilled EVE 280N cells, ensuring a proper fit with 6mm threads/blots.
- M8 bolts for terminal connections, inserted from inside the battery through brass inserts in the lid.
- 4x M4 countersunk screws for securing the lid.
Torque Specification: Battery terminals should be tightened to 6-8 NM. Loose terminals are explicitly warned to cause cell and battery failure.
BMS: The kit utilizes an SFK-150 4s BMS, which comes pre-wired for ease of assembly. The BMS includes an NTP probe for temperature monitoring, which can be mounted on the underside of the top plate or directly to a cell.
Voltage Readings: After wiring, expected voltage readings are 3.6V, 7.2V, 10.8V, and 14.4V, assuming the battery cells are fully charged during installation.
Wiring Schematic (4s configuration):
- Black wire = cell 1 negative
- 1st white wire = cell 1 positive
- 2nd white wire = cell 2 positive
- 3rd white wire = cell 3 positive
- Red wire = cell 4 positive
V1 vs. V2 Kits:
- Both kits are largely similar.
- The V2 kit accommodates taller cells and cells with welded studs by incorporating a spacer and an internal riser design.
- V1 kits allow direct installation of the top plate onto the bottom plate.
- V2 kits include taller mounting screws for attaching the top plate to the bottom plate.
- The V2 kit's unique feature is the middle spacer, which differentiates its external appearance from the V1 kit, while the lid and bottom remain the same.

Usage Features

DIY Assembly: The primary usage feature is the ability for users to assemble their own battery packs, offering a hands-on experience and potentially cost savings.
Prismatic Cell Compatibility: The kits are designed to support various prismatic cells, providing flexibility in cell choice.
Top Balancing: A crucial pre-assembly step involves "top balancing" the battery cells, where all cells are charged in parallel to ensure they start at the same voltage. A tutorial video link is provided for this process.
Series Configuration: Cells are arranged in a series configuration, with specific instructions for positive and negative terminal placement.
EPO Foam: The enclosure uses EPO foam to exert pressure on the cells, keeping them securely in place.
BMS Integration: The SFK-150 4s BMS simplifies the electrical setup, with pre-wired components that only require screwing in.
Monitoring Apps: Users can connect to their battery for monitoring and testing via dedicated apps available on Google Play Store (Sun Fun Kits BMS) and Apple iOS App Store (Sun Fun Kits BMS or XiaoXing BMS). The XiaoXing BMS app offers additional parameter tweaking.
Carry Handles: The kit includes carry handles that buckle into the case's ridge for easy transport.

Maintenance Features

Removable Lid: The design allows for the lid to be removed, facilitating access for maintenance or inspection.
Water Resistance (Optional): Silicone sealant can be added to the lid's ridge to increase water/moisture resistance, providing a perimeter shield while maintaining the lid's removability. Permanent glue or sealant is not recommended.
Thread Locker: The use of thread locking compound on terminal bolts is recommended to prevent loosening, which is critical for battery longevity and safety.
Wire Management: Double-sided sticky tape and Velcro straps are suggested for securing components like the Bluetooth dongle or supplementary balancer and tidying up loose wires, contributing to a more organized and potentially easier-to-maintain internal layout.
Warning against Loose Terminals: The manual explicitly warns that loose terminals will cause cells and batteries to fail, emphasizing the importance of proper tightening during assembly as a key maintenance consideration.
No Power Tools for Top Plate: Users are instructed to use only hand tools and tighten gently when attaching the top plate, preventing potential damage during assembly that could lead to future maintenance issues.

Sun Fun Kits V1 - Page 10