How to Wire Batteries in Series vs Parallel — Solar Battery Guide
How you wire your battery bank determines the system voltage and total capacity. Getting this right is critical for compatibility with your Deye hybrid inverter and for battery safety.
Series Wiring
Connecting batteries in series adds voltages while keeping capacity (Ah) the same. Example: four 12V 100Ah batteries in series = 48V 100Ah (4.8 kWh).
- Connect positive of battery 1 to negative of battery 2, and so on
- The first battery's negative and last battery's positive are your system terminals
- All batteries must be the same type, brand, and age
Parallel Wiring
Connecting batteries in parallel adds capacity while keeping voltage the same. Example: two 48V 100Ah batteries in parallel = 48V 200Ah (9.6 kWh).
- Connect all positive terminals together and all negative terminals together
- Use equal-length cables to ensure balanced current flow
Series-Parallel (Combined)
For larger banks, combine both methods. First wire groups in series to reach target voltage, then wire those groups in parallel for more capacity.
Deye Battery Configuration
Deye BOS-G LiFePO4 batteries are 51.2V modules that stack in parallel. Each module adds 5.12 kWh to your bank. Simply stack and connect up to 4 modules (BOS-G) or 8 modules (SE-G5.1 Pro). The built-in BMS handles all balancing automatically.
| Modules | Capacity | Voltage | Configuration |
|---|---|---|---|
| 1 | 5.12 kWh | 51.2V | Single |
| 2 | 10.24 kWh | 51.2V | Parallel |
| 3 | 15.36 kWh | 51.2V | Parallel |
| 4 | 20.48 kWh | 51.2V | Parallel |
Safety Rules
- Never mix battery types, ages, or capacities in the same bank
- Use appropriately rated cables and fuses for the total current
- Always disconnect the inverter before reconfiguring batteries
- Wear insulated gloves — 48V systems can deliver dangerous current
Frequently Asked Questions
Should I wire batteries in series or parallel for solar?
It depends on your system voltage. Deye hybrid inverters use 48V nominal, so Deye BOS-G batteries connect in parallel to add capacity while maintaining 51.2V. For lead-acid, you may need series connections to reach 48V from 12V batteries.
How many Deye BOS-G batteries can I connect together?
You can connect up to 4 Deye BOS-G5.1 modules in parallel for 20.48 kWh total, or up to 8 SE-G5.1 Pro modules for 40.96 kWh. They stack vertically and connect automatically through the built-in BMS.
Can I mix different battery brands in the same bank?
No. Never mix different battery brands, types, ages, or capacities in the same bank. This causes imbalanced charging, reduced lifespan, and potential safety hazards. Always use identical modules from the same manufacturer.
