1. Parallel Voltage Principle

When batteries are connected in parallel, the voltage remains the same as a single battery, while the current capacity adds up. For this to work properly, all batteries must have identical voltage ratings.

2. How Parallel Voltage Works

The parallel voltage formula is:

Where:

• \( V1 \) — Voltage of first battery
• \( V2 \) — Voltage of second battery

Explanation: In a parallel connection, the voltage across all components is the same. The system voltage will equal the voltage of each battery (assuming they're identical).

3. Practical Examples

Example 1: Two 12V batteries in parallel → System voltage = 12V
Example 2: Three 3.7V Li-ion cells in parallel → System voltage = 3.7V
Example 3: Mismatched 12V and 9V batteries → Dangerous situation (not recommended)

4. Safety Considerations

Important: Never connect batteries with different voltages in parallel. This can cause excessive current flow between batteries, leading to overheating or explosion.

5. Frequently Asked Questions (FAQ)

Q1: Why must voltages be equal in parallel?
A: Unequal voltages create current flow between batteries, which can be dangerous and damage the batteries.

Q2: What happens to capacity in parallel?
A: The total capacity (Ah) adds up while voltage stays the same.

Q3: Can I parallel different battery types?
A: Not recommended, even if voltages match. Different chemistries have different charge/discharge characteristics.

Q4: How to check if batteries are suitable for parallel?
A: Verify identical voltage, chemistry, age, and state of charge.

Q5: What's the maximum batteries I can parallel?
A: Limited by wiring and connectors. Follow manufacturer guidelines.