SOK 48V 100Ah LiFePO4 Battery Review and Thermal Test

Steps

1. 1

   Step 1: Introducing the SOK 5 kWh battery

   Watch this part (0:00)

   I normally make 16 kWh battery packs for my home storage setup. I often get feedback from viewers that 16 kWh is too much, so I am reviewing the SOK 48 volt 100 A battery. This unit comes ready-made so we do not have to assemble it, which makes the process much easier. These units are designed to be placed in a server rack and provide 5 kWh of storage.

   The advantage of these batteries is that you can stack and daisy-chain multiple units together. You can reach totals of 5, 10, 15, 20, 25, or 30 kWh combined. A single battery pack is 100 A, which means 0,5C with maximum charging and discharging limited to 50 A.

   What I used

   Item	Amount	Notes
   SOK 48V 100Ah LiFePO4 Battery	1	Server rack battery

2. 2

   Step 2: Unboxing the SOK battery

   Watch this part (0:55)

   I start with the unboxing to see what is inside the box and how it is delivered. The box is very heavy because the battery weighs 45 kilos. Inside the box, I find the instruction manual, the cables to link units together so they work as one, an extra core cable, and a very important test report.

   What I used

   Item	Amount	Notes
   Instruction manual	1	Included in box
   Linking cables	1	For connecting units
   Extra core cable	1	Included accessories
   Test report	1	Quality document

3. 3

   Step 3: Reviewing the factory test report

   Watch this part (1:37)

   I look at the test report to check the actual capacity. While this is nominally a 100 A hour battery, the report shows it has 104,87 A hours. All specifications like switches, Bluetooth LED, and internal resistance are checked and documented in the report that is sent along.

4. 4

   Step 4: Checking battery certifications

   Watch this part (2:06)

   There is often panic about battery certifications and approvals. On the side of this battery, you can see CE approval, UN UL approval, and UN 38.3. This proves the battery is certified.

   • CE approval

   • UN UL approval

   • UN 38.3

5. 5

   Step 5: Inspecting internal build quality and cells

   Watch this part (2:27)

   I am going to void the warranty immediately so you do not have to. I open the housing to check what is inside and look at the build quality. Inside, there is a resin sheet screwed on top of the cells to prevent short circuits. Unfortunately, one screw is too tight to turn, but I can unscrew the panel off.

   This reveals that the busbars are not screwed on, but welded onto the cells. Every cell has a QR code, which I traced to Leoch cells from the manufacturer Cornex, produced on October 9, 2025.

6. 6

   Step 6: Measuring initial cell voltage and resistance

   Watch this part (3:33)

   Out of the box, I want to know the delivery voltage of the cells. I measure 3,29 V, 3,294 V, 3,294 V, 3,294 V, and 3,294 V, meaning the pack is already well-balanced. Next, I measure the internal resistance carefully to avoid short circuits by placing the probes on the terminals.

   The cells show 3,296 volts of voltage and 0,45 mOhm of resistance, proving good cell quality. Above the cells, we can see the frame section where the balancing wires are already attached. Besides screwing, the balancing wires are also glued so they cannot vibrate loose.

   Warning

   Be careful not to cause a short circuit when measuring internal resistance with probes.

7. 7

   Step 7: Inspecting internal wiring, BMS, and heating mat

   Watch this part (4:44)

   In the front of the housing, we can see the BMS, circuit breaker, and terminals. The cables used between the battery positive pole and the circuit breaker are two 10 mm2 cables. One 10 mm2 cable can handle 40 to 60 A, so together you can pull about 80 A through these cables for both positive and negative sides connected to the BMS.

   Another advantage of this battery is the heating mat lying at the bottom, which is connected to the BMS. This allows the battery to function and keep itself warm even in a hot or cold shed or outdoors. The SOK battery does not use a JK BMS like my earlier videos, so it lacks a front display.

   What I used

   Item	Amount	Notes
   10 mm2 cables	2	Between positive pole and breaker
   Heating mat	1	At the bottom, connected to BMS

8. 8

   Step 8: Disconnecting old batteries from the Victron setup

   Watch this part (6:21)

   I will connect the SOK battery to my Victron home battery setup featuring three 5 kVA units. I disconnect my original batteries from the busbar so this SOK unit is the only one connected. This single battery will handle emergency backup power for my entire house, charging and discharging near its 50 A limit.

   I turn off the inverter so all voltage drops off the house. Then I disconnect the battery cable. I use a special custom tool that I made to click onto the cable and protect it so it cannot cause a short circuit. I can also switch off the other battery at the front, making the whole house sparkless and removing voltage from the busbar.

   What I used

   Item	Amount	Notes
   Victron home battery setup 3x 5kVA	1	Inverter system
   Custom protective tool	1	To protect cable ends from shorting

9. 9

   Step 9: Connecting the SOK battery to the Victron busbar

   Watch this part (7:52)

   I removed one cable from my busbar and disconnected the other at the battery. I placed new cables running from the busbar to the SOK battery. Now I can switch on the battery, restoring voltage to the busbar and allowing the Cerbo and Multiplus units to start up.

   The whole set is up and running on this single battery. I limited the Multiplus set to pull a maximum of 2400 W from the battery and charge it with a maximum of 50 A, which is the 0,5C rating allowed for this battery.

   What I used

   Item	Amount	Notes
   New battery cables	2	Connecting SOK battery to busbar

10. 10

    Step 10: Setting up baseline thermal imaging during a heatwave

    Watch this part (9:01)

    I will now charge the battery with the full 50 A, use a thermal camera to inspect it, and check if it gets warm. It is midsummer in the Netherlands during a heatwave and it is boiling hot, with even the walls at 30 degrees Celsius. Looking at my thermal camera, the top left shows an indoor temperature of 29,5 degrees Celsius.

    The three Multiplus units, Cerbo, and screen are visible, with my old battery cabinet below holding the new SOK battery on top. Inside the BMS, one power supply point gets warm. For a baseline test, the center of the cells measures 26 degrees Celsius.

    What I used

    Item	Amount	Notes
    Thermal camera	1	Used for thermal imaging

11. 11

    Step 11: Installing the SOK BMS app and configuring Victron communication

    Watch this part (10:39)

    The battery is charging at 48 A, which is about 2500 to 2600 W. While waiting, I install the SOK BMS app on my phone. I search for the SOK battery via Bluetooth, connect to it, and read out the data showing 54 volts, 48 A charging current, and 51,92% state of charge. A major advantage of this battery is that I do not need to configure any BMS settings.

    Next, I plug in a type A CAN bus cable, with VE.CAN on one end and BMS CAN on the other, connecting it to the battery CAN port. In the SOK app, I go to the inverters tab, select Victron, confirm with yes, and set it to communicate with the Victron setup.

    What I used

    Item	Amount	Notes
    SOK BMS app	1	Mobile application
    VE.CAN to BMS CAN cable	1	Type A communication cable

12. 12

    Step 12: Integrating the SOK battery into Victron VRM

    Watch this part (12:05)

    In the Victron VRM, the top left still shows my old state of charge measured by the shunt, because my setup still thinks the old full battery pack is connected at 83%. At the bottom, the second battery appears as the SOK battery with 54,32 volt voltage, charging at 48,7 to 49 A around 2600 W, at 60 to 61% state of charge.

    The battery must first be fully charged until it can go no further, resetting it to 100%, after which it will stay in sync. The Victron also resets both the shunt and battery to 100% when fully charged so they match. This shows how a single data cable fully integrates the SOK battery into Victron, and it supports many other brands as well.

13. 13

    Step 13: Thermal inspection near full charge

    Watch this part (13:14)

    The battery is almost full at 98% and 55 volts. Using the thermal camera, I see the BMS is slightly warmer. Measuring the cells, they are now 33 degrees Celsius, which is 7 degrees warmer than before.

    Turning the unit around, the BMS is warmer, but the main power cables stay relatively cool. The cables get slightly warm but not excessively, which is great.

14. 14

    Step 14: Testing house emergency backup power on a single SOK battery

    Watch this part (14:07)

    I test whether the battery can run my house in emergency backup mode. I turn off all solar panels so the house gets no solar help, and then I switch off the main grid breaker. The entire house now runs on emergency power from a single SOK battery.

    The grid status shows as gone, and the house continues running while drawing 620 W from the battery to power the home.

15. 15

    Step 15: Final thermal check after an hour of high discharge

    Watch this part (14:43)

    After the battery supplies about 45 to 50 A back to the house for over an hour, I do another thermal check on the cells. The battery is under heavy demand, and we can see warm and cold parts. The busbars are warmer, but being metal they do not discolor easily, and the cells measure about 34 degrees Celsius, which is 1 degree warmer than before.

    Checking the other side, the BMS is slightly warmed up and the cables are mildly warmed up, but still nothing to worry about since it is only a few degrees warmer than the rest.

16. 16

    Step 16: Concluding the review and mentioning future battery comparisons

    I hope you enjoyed this review of the SOK 48 volt 100 A battery. I have ordered this cabinet specifically to show different batteries and compare their differences, and there will be many more coming. If you want to see more batteries, hit the subscribe button so you do not miss anything.

17. 17

    Step 17: Takeaways

    • The SOK 48V 100Ah battery offers 5 kWh of storage with CE and UL certifications.

    • Internal inspection revealed welded busbars, Cornex Leoch cells, and glued balancing wires.

    • The built-in heating mat allows the battery to operate in cold environments.

    • A single VE.CAN to BMS CAN cable allows smooth integration with Victron systems.

    • Thermal testing showed stable temperatures during 50 A charge and discharge cycles in a heatwave.