How do I wire my lithium batteries in parallel?

Wiring batteries in parallel increases capacity (amp-hours and runtime) while keeping the voltage the same. You do it by connecting positive to positive and negative to negative, then pulling your main power from the combined outputs.

Parallel wiring basics

• Voltage stays the same (two 12V batteries in parallel = 12V)

• Capacity adds up (two 12V 100Ah in parallel = 12V 200Ah)

How to wire it (step-by-step)

For two 12V batteries in parallel:

1. Turn everything off, disconnect charger and loads.

2. Connect Battery 1 positive (+) to Battery 2 positive (+) with a jumper cable.

3. Connect Battery 1 negative (-) to Battery 2 negative (-) with a jumper cable.

4. Connect your system’s main positive and main negative to the bank.

Best practice for even draw:

• Pull main positive from Battery 1 (+) and main negative from Battery 2 (-) (opposite corners). This helps both batteries share the load and charge more evenly.

Rules you need to follow

• Use matching batteries only (same model, same capacity, same age). Don’t mix sizes or brands.

• Start them balanced. Fully charge each battery before paralleling them.

• Fuse each battery if possible. A fuse near each battery positive protects the system if a cable shorts.

• Use proper cable size. Parallel banks can support high current, but undersized cables cause heat and voltage drop.

Quick check

After wiring, check voltage at the main leads with a multimeter:

• It should read the same voltage as a single battery of that type (example: around 13V+ on a charged 12V LiFePO4 battery).

If you would like additional support directly from a customer support technician, please open a ticket at the link below:
https://dakotalithium.com/sales-technical-support/how-to-contact/