Building a 16kWh LiFePO4 Battery for a Victron Home Energy Storage System

Steps

1. 1

   Step 1: Step 1: Plan my home battery system

   I wanted to make my home less dependent on the electricity grid. I already have twelve solar panels, but I also want to store the electricity they generate.

   My plan is to build a three-phase Victron home battery system with around 48 kWh of storage.

   I decided to build three separate 16 kWh battery packs. This is how I built the first one.

   Item	Value
   Solar panels	12
   Planned battery packs	3
   Capacity per pack	Approximately 16 kWh
   Planned total storage	Approximately 48 kWh
   System	Three-phase Victron

2. 2

   Step 2: Step 2: Choose the battery cells

   I chose sixteen EVE 314 Ah LiFePO4 battery cells for my first battery pack.

   Each cell has a nominal voltage of 3.2 V. By connecting sixteen cells in series, I get a 51.2 V battery with around 16 kWh of storage.

   The cells cost approximately €100 each. They are the most expensive part of my build.

   What I used:

   • 16 x EVE 314 Ah LiFePO4 battery cells

   Item	Value
   Battery chemistry	LiFePO4
   Cell manufacturer	EVE
   Number of cells	16
   Capacity per cell	314 Ah
   Voltage per cell	3.2 V
   Total battery voltage	51.2 V
   Total battery capacity	16.08 kWh
   Configuration	16S
   Approximate price per cell	€100

3. 3

   Step 3: Step 3: Arrange the cells in a 4x4 layout

   I started by placing the sixteen cells in a four-by-four layout.

   LiFePO4 cells expand a little when charging and shrink again when discharging. I call this the cells breathing.

   I didn't want to put all sixteen cells in one long row. The expansion could put extra pressure on the connections between the cells.

   The 4x4 layout makes the battery more compact. I'm happy with this choice and want to use the same layout for my next two batteries.

   What I used:

   • 16 x EVE 314 Ah LiFePO4 cells

4. 4

   Step 4: Step 4: Put plastic separators between the cells

   After arranging the cells, I placed polypropylene plastic separators between them.

   I didn't want the metal cases of the battery cells touching each other.

   The separators keep the cells apart and provide electrical insulation.

   What I used:

   • Polypropylene (PP) plastic separators

5. 5

   Step 5: Step 5: Build the battery box

   Next, I built a box to hold all sixteen cells.

   I chose fire-retardant MDF because it's relatively cheap and easy to work with.

   I made the box around the 4x4 cell layout. I wanted everything to fit closely together without making the battery bigger than necessary.

   The battery box will eventually go inside a steel cabinet.

   What I used:

   • Fire-retardant MDF panels

6. 6

   Step 6: Step 6: Add the cell compression system

   With the box built, I needed a way to hold the battery cells together.

   I used threaded rods and a removable side panel. The rods pull the panel towards the cells and keep them in place.

   This was important to me because the cells expand and contract when the battery is used.

   I wanted to keep the design simple and make it possible to remove the panel later.

   What I used:

   • Threaded rods

   • Nuts

   • Washers

   • Removable MDF side panel

7. 7

   Step 7: Step 7: Make a mounting bracket for the BMS

   I needed somewhere to mount the Battery Management System, or BMS.

   I wanted the BMS on the side of the battery box, where I could still reach it.

   I designed a custom bracket and printed it with my 3D printer.

   What I used:

   • 3D printer

   • Custom 3D-printed BMS bracket

8. 8

   Step 8: Step 8: Install the JK BMS

   I chose a 150 A JK BMS for my battery.

   The BMS monitors the battery cells and helps keep them balanced. It also lets me see information about the battery through an app on my phone.

   I mounted the BMS on the bracket I had printed earlier.

   The BMS costs approximately €100. I'm happy with this choice because it gives me a lot of information about what is happening inside the battery.

   What I used:

   • 1 x JK BMS, 150 A

   • 1 x 3D-printed mounting bracket

   • BMS mounting hardware

   Item	Value
   BMS brand	JK
   Current rating	150 A
   Approximate price	€100
   Monitoring	Smartphone app
   Connection	Bluetooth

9. 9

   Step 9: Step 9: Install the Bluetooth activation button

   I wanted to be able to check the battery without opening the box.

   I installed a small button on the front of the enclosure.

   I can use this button to activate Bluetooth and connect to the BMS with my phone.

   What I used:

   • 1 x Bluetooth activation button

10. 10

    Step 10: Step 10: Connect the battery cells

    Next, I connected the sixteen cells together in series using busbars.

    I had to be careful while working around the battery terminals. The cells still have voltage even when the battery isn't connected to anything.

    I used a ratchet socket instead of an open-ended spanner. I also wrapped the socket with insulating tape.

    I got that tip from a viewer on one of my earlier videos. It's something I'll keep doing on my next battery builds.

    What I used:

    • Battery busbars

    • Terminal connection hardware

    • Ratchet socket

    • Insulating tape

11. 11

    Step 11: Step 11: Connect the BMS measurement wires

    With the cells connected, I started connecting the BMS measurement wires.

    The BMS needs to read the voltage of each cell separately.

    I connected the measurement wires to the battery cells and checked the connections against the JK BMS documentation.

    I took my time with this part. I didn't want to connect anything incorrectly.

    What I used:

    • JK BMS wiring harness

    • BMS measurement wires

12. 12

    Step 12: Step 12: Configure the JK BMS

    Once everything was connected and checked, I opened the JK BMS app on my phone.

    I connected to the BMS using Bluetooth and entered the battery information.

    The app lets me see the total battery voltage, individual cell voltages, remaining capacity, state of charge, internal resistance readings, and cycle count.

    What I used:

    • Smartphone

    • JK BMS app

    • Bluetooth connection

    BMS setting	Value
    Battery type	LiFePO4
    Number of cells	16
    Battery capacity	314 Ah
    Nominal voltage	51.2 V
    BMS rating	150 A

13. 13

    Step 13: Step 13: Install the battery fuses

    Next, I installed the fuses for the battery's external connections.

    I'm planning to connect three battery packs in parallel. The complete system is designed around a maximum combined discharge current of approximately 300 A.

    That means I'm aiming for around 100 A per battery when the load is shared equally.

    I installed one 100 A fuse on the positive side and another 100 A fuse on the negative side.

    What I used:

    • 2 x 100 A fuses

    • 2 x Fuse holders

14. 14

    Step 14: Step 14: Mount the external battery connections

    After installing the fuses, I mounted the fuse holders on the outside of the battery box.

    These also serve as the connection points for the battery cables.

    I wanted the connections outside the enclosure so the battery could eventually be connected to my Victron system.

    What I used:

    • 2 x External fuse holders

    • Battery power cables

    • Cable connection hardware

15. 15

    Step 15: Step 15: Add a transparent front panel

    With the main components installed, I started finishing the battery box.

    I wanted to be able to see the cells without leaving the front completely open.

    I installed a transparent plexiglass panel on the front of the enclosure.

    Now I can look inside the battery and still have a cover over the cells and connections.

    What I used:

    • 1 x Transparent plexiglass panel

    • Panel mounting hardware

16. 16

    Step 16: Step 16: Make brackets for the cables

    I wanted to keep the cables inside and around the battery box organised.

    I designed and 3D-printed several small brackets.

    I used them to guide the cables between the BMS and the external fuse holders.

    This made the finished battery look much tidier.

    What I used:

    • 3D printer

    • Custom 3D-printed cable brackets

17. 17

    Step 17: Step 17: Check the finished battery

    After assembling the battery, I opened the JK BMS app again.

    I checked the total battery voltage, the voltage of each cell, and the reported state of charge.

    The cells appeared very closely balanced during my first checks. I was happy to see that.

    The battery is now assembled, but I haven't documented a full-capacity discharge test yet. It also hasn't been integrated into my three-phase Victron system.

    What I used:

    • Completed 16 kWh LiFePO4 battery

    • Smartphone

    • JK BMS app

18. 18

    Step 18: Results so far

    I've finished assembling my first 16 kWh LiFePO4 battery.

    The complete battery weighs approximately 130 kg. It has sixteen EVE cells, a JK BMS, a custom MDF enclosure, external fuse holders, and a transparent front panel.

    I'm happy with how compact everything turned out. The first BMS readings also looked promising.

    Item	Result
    Battery cells	16 x EVE 314 Ah
    Battery configuration	16S
    Nominal battery voltage	51.2 V
    Nominal storage capacity	16.08 kWh
    BMS	JK 150 A
    Fuses	2 x 100 A
    Enclosure	Fire-retardant MDF
    Front panel	Transparent plexiglass
    Battery weight	Approximately 130 kg
    Cell balance	Closely balanced during initial checks
    Victron integration	Not yet completed