Connecting battery packs depends on whether you need increased voltage (series connection) or increased capacity/current (parallel connection). It's crucial to understand the difference to achieve your desired outcome and avoid damaging the batteries or the connected device.
Connecting Batteries in Series (Increasing Voltage)
To connect batteries in series, you link them in a chain, increasing the overall voltage while maintaining the same amp-hour (Ah) capacity.
- The process: According to the reference material, "To connect a group of batteries in series you connect the negative terminal of one battery to the positive terminal of another and so on until all batteries are connected, you would then connect a link/cable to the negative terminal of the first battery in your string of batteries to your application, then another link..."
- How it works: The negative terminal of one battery connects to the positive terminal of the next, and so forth. This arrangement adds the voltages of each battery together.
- Example: If you connect three 12V batteries in series, the resulting pack will be 36V. The amp-hour (Ah) rating will remain the same as a single battery.
Connecting Batteries in Parallel (Increasing Capacity/Current)
Parallel connections increase the amp-hour (Ah) capacity of the battery pack while keeping the voltage the same.
The process
- Connecting positive to positive and negative to negative: Connect all the positive terminals together and all the negative terminals together.
- Voltage remains the same: This configuration maintains the original voltage of a single battery.
- Amp-hour capacity increases: The total amp-hour capacity is the sum of the individual battery capacities.
Practical Considerations
- Use identical batteries: For both series and parallel connections, it is essential to use batteries that are the same voltage, capacity (Ah), age, and manufacturer. Mismatched batteries can lead to imbalance, reduced lifespan, and potential safety hazards.
- Proper wiring: Use appropriately sized wires and connectors to handle the current. Undersized wiring can cause voltage drop and overheating.
- Fuses: Include fuses in the circuit to protect against short circuits and overcurrents. Place a fuse as close to the positive terminal of each battery as possible.
- Charge appropriately: Make sure your charger is compatible with the voltage and capacity of the resulting battery pack.
Example
| Connection Type | Configuration | Resulting Voltage | Resulting Capacity (Ah) |
|---|---|---|---|
| Series | Three 12V, 100Ah batteries connected negative to positive | 36V | 100Ah |
| Parallel | Three 12V, 100Ah batteries connected positive to positive and negative to negative | 12V | 300Ah |
