The best way to connect 16 12V batteries to make a 48V system is by using a series-parallel configuration. This means connecting the batteries in series groups first and then connecting those groups in parallel. Here’s how to do it:
- Connect the batteries in series groups: Arrange the 16 batteries into four groups of four batteries each. In each group, connect the batteries in series by connecting the positive terminal of one battery to the negative terminal of the next battery. This will create four 48V series groups.
Connecting 4 12v batteries in series to get four sets of 48v - Connect the series groups in parallel: Now, connect the positive terminals of each series group together, and connect the negative terminals of each series group together. This will create a parallel connection between the four series groups, maintaining the 48V voltage while increasing the overall capacity and current of the system.
I highly recommend using the busbars shown in the diagram. These busbars (positive and negative) will distribute the power equally through the series string.
You can get these busbars. They have 6 studs and are limited to 150A.
If you do not have these busbars, then a series string will work harder than the other, leading to a reduced lifespan of the whole battery pack.
If you do not have busbars, you can use the following setup, which is the next best thing you can do.
You can add fuses to protect each series string to complete the system. This is how that will look:
If you are going to use this system, I recommend getting the Victron Lynx distributor It’s a positive and negative busbar in one with M8 studs and fuse holders.
If you plan to build this system with lithium batteries, I recommend using server rack batteries. These are boxes that fit in a server rack which are 48V, 100Ah. Read my expert write-up about the best lithium server rack here.
If you connect batteries in series, ensure they are at the same state of charge! Always use safety goggles and insulated tools when working with batteries! [custom-related-posts title=”Related Posts” none_text=”None found” order_by=”title” order=”ASC”]
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I followed this guide in your book but I would like to also connect my Li Time battery balancer to these 16 (12v lifepo4) batteries but don’t know where to connect them?
We purchased land off grid and want to move out there into the shed we had put out there. I first built a 12 volt system and then learned of its limitations and how 4 batteries would not work for me. So I bought more batteries to get to 16 12v batteries to make a 48v system and gifted my 12 volt inverter to my neighbor. I’d like to try and get another string of 4 more batteries in a month or two and would like to know how would I connect the battery balancer by li time with four connectors? And if I add a fifth string then what would I do?
Its better to have a 48V battery instead of 4x12V batteries. If you use a balancer you use one balancer per 4 sets of batteries, so one balancer for 4 12V batteries.