How to Connect and Charge 

Lithium Batteries?


1. Preparation丨What is BMS?

2. How to connect the lithium battery correctly?

3. What is the difference between parallel batteries and series batteries?

4. Is it possible to charge multiple batteries at the same time?

1. Preparation丨What is BMS?

A battery management system (BMS) is a system that manages and protect the battery from over-charging、over-discharging、over-current、over-voltage、over-temperature and short circuit. Before setting up the battery bank, please check the number of batteries allowed to be connected in series.

Taking Eco-Worthy 12v batteries as an example, our BMS can handle 4 batteries in series at the same time. There are no restrictions on parallel connection, but we recommend to connect up to 4 batteries in parallel to protect the battery and extend the battery lifespan.

2. How to connect the lithium battery correctly?

Please check the positive and negative poles and make sure you connect the correct terminals. Then please use the wrench to tighten the screw, battery cable and spring gasket. If you want to use a alligator clip, please clamp it to the copper terminal. 

(Don't clamp the stainless steel screw)


Do not connect different brands, capacities, and cycles lithium batteries in series or parallel. Due to the difference in internal resistance and capacity, it is easy to cause battery failure.

3. What is the difference between parallel batteries and series batteries?

When you connect two 12 volt batteries in series, it will set up a 24 volt battery pack, but the capacity does NOT increase. If you connect two 12 volt batteries in parallel, it is still a 12 volt battery pack, but its capacity increases.

Batteries in Series: 

1) Connecting batteries in series can increase voltage which is useful when we need to power high voltage applications.

2) Connecting batteries helps to distribute the load between batteries which can increase the efficiency of the battery bank.

(Series Example: Connect 2*12v 100ah lifepo4 batteries to set up a 24v 100ah power bank)

Batteries in Parallel

1) Connecting batteries in parallel can increase the capacity. It means you can run the device longer. It is perfect for the device requiring high capacity.

2) Reduce the risk of system failure. If one battery in the parallel connection fails, the others can continue to power the device.

3) Reduce the risk of overcharged. When batteries are connected in parallel, they all receive the same voltage to avoid overcharging.

(Parallel Example: Connect 12v 100ah lifepo4 batteries in parallel to create a 12V 200ah bank)

Can I connect the batteries in series and parallel at the same time?

Yes, you can connect according to the voltage and capacity you need. For safety, please connect in series first and then in parallel.

4. Is it possible to charge multiple batteries at the same time?

1) Can I use lead-acid battery charger to charge lithium battery?

It is recommended to use a special charger for lithium batteries to help charge the battery faster. The lead-acid battery charger may damage the battery. 

2) Charge in series

If the charger supports 24v, it can charge two 12v battery in series. If the charger supports 48v, it can charge four 12v battery in series.

Reminder: If multiple batteries are charged at the same time, the charger will stop charging when the battery pack reaches a certain voltage. It means one battery is charging faster than the others, potentially causing insufficient capacity or shortening the lifespan of one or more batteries. Therefore we recommend to add a Battery Balancer Equalizer or charge each battery individually.