Looking for a way to build a powerful and smart 12V battery at home? 🔋✨ In this guide, I'll show you how to create a DIY 12V battery using recycled 18650 cells and a Daly Smart BMS — plus an awesome bonus: we'll also build a Mini DC IPS Auto Load/Off Changeover Circuit for automatic power management!

📦 Materials You’ll Need

1. 18650 Lithium-ion Cells (tested and matched)
2. Daly 4S 12V Smart BMS (Bluetooth)
3. Nickel Strips
4. Spot Welder (or strong soldering setup)
5. XT60 Connectors (optional)
6. Heat Shrink Wrap or Battery Case
7. Balance Wires
8. Multimeter

🛠 Step-by-Step Build Guide

1. Cell Testing and Preparation

Test each 18650 cell for voltage, internal resistance, and capacity.

Group cells with similar specs for best performance and safety.

2. Building the 4S Battery Pack

Connect cells in a 4S (4 Series) configuration.

Increase capacity by adding cells in parallel (4S2P, 4S3P, etc.).

3. Spot Welding the Cells

Use a spot welder for safe and solid connections with nickel strips.

Avoid direct soldering on cells to prevent heat damage.

4. Installing the Daly Smart BMS

Connect BMS main positive and negative wires.

Attach balance leads correctly to each series connection.

Ensure no loose wires or short circuits.

Daly Smart BMS will allow real-time monitoring of battery health via Bluetooth!

5. Testing the Pack

Verify voltage at every series connection point.

Use Daly Smart BMS App to check live cell voltages, temperatures, and currents.

📈 Why Choose Daly Smart BMS?

1. Real-time Bluetooth Monitoring
2. Automatic Balancing
3. Overcharge & Over-discharge Protection
4. Current Overload & Temperature Protection
5. Smart Mobile App Access
6. This ensures professional-grade safety and performance in your DIY battery.

⚡ Applications of 12V Smart Battery

1. DIY Solar Power Systems
2. Backup Power Supply
3. Portable Camping Power Stations
4. E-bikes & Scooters
5. Small Home UPS Systems

🛠 Bonus Project: Mini DC IPS Auto Load/Off Changeover Circuit

To make your system even smarter, add an automatic load/off switch. This project switches your load between main power and battery backup automatically!

🔥 PCB Layout

Here’s the Mini DC IPS PCB layout:

📄 Circuit Diagram

Detailed schematic for the changeover system:

🧩 Components List

1. Relay: SRD-05VDC-SL-C
2. Diodes: 1N5408
3. Capacitors: 4700µF and 0.1µF
4. Resistors: 1kΩ
5. LEDs for Status Indication
6. Connectors for Battery, Load, and Input
7. 
   

⚙ How It Works:

1. When Main Power is ON: Load is powered by the input supply through the relay.
2. When Main Power is OFF: The relay automatically switches to battery backup, maintaining continuous power to your devices.
3. LED Indicators: Show whether the system is running on main power or battery.
4. Perfect for:
5. Internet Routers
6. CCTV Systems
7. LED Lights
8. Mini Servers

📢 Final Safety Tips

✅ Always work in a ventilated space.

✅ Test each battery cell individually before assembling.

✅ Double-check all BMS connections carefully.

✅ Use proper insulation to prevent shorts and accidents.

🚀 Conclusion

Building a DIY Smart 12V Battery with 18650 Cells and combining it with a Mini DC IPS Auto Load/Off Changeover Circuit is an incredible way to save money, learn electronics, and create reliable backup systems!

Whether it's for solar power, camping, or just emergency backup, this DIY project brings real, practical value. 🔥

👉 Watch the Full Step-by-Step Video Guide Here: