USA-Made Lithium Battery Review – SFK 300 Amp Hours

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In this part one video, my first look and a quick test of an interesting 12V 300Ah lithium battery from a company called SFK (SunFunKits). Don’t let the funny name fool you. This is a sweet looking, well-put-together battery made in the USA. It has more features than I’ve ever encountered in all my battery reviews.

I’m sure any DIY geek will love this battery, but it’s also easy to use for anyone. Both the user manual and app are top-notch, very informative. Stay tuned for more videos coming in the future as I use and test out this cool new battery.

(Part 1 – Introduction)  SFK 300Ah Battery Review


  • 4.0 kilowatt hours of reliable lithium power, replaces up to 6 lead acid / agm batteries (100ah) and is designed to be discharged to 100% of available capacity without harm to the battery.
  • Up to 2.4 kilowatts of peak power, and 1500 watts of continuous power.
  • GEN 2 I/O Switch allows bluetooth to be turned on/off, full active balancer control, and a simplified heating control system.
  • Expected cycle life of 2000-3000 cycles at 80% DOD, and up to 5000 cycles at 50% DOD, 10-15 year usage life.
  • Fully compatible with existing 12v infrastructure including standard 12v lead acid/agm battery chargers, trickle chargers and high voltage DC systems up to 48v (when linked in series with 4 batteries).
  • Built-in cell heaters to allow for low temperature charging, temperature to activate heaters can be set inside the app.
  • Smart phone/device compatible with Bluetooth monitoring/configurable app. Available for IOS/Android.
  • Can be linked in series up to 48v (4 batteries in series) as well as up to 4 in parallel with a combined output of 3.0 KW continuous.
  • Automatic low/high temperature and low/high voltage cut-off to stop battery damage from occurring.
  • Automatic short circuit prevention as well as over charge and over discharge prevention.

Pt. 2 – App Features & Capacity Benchmark Test

In part two of my SFK 300Ah lithium battery review, we look at its companion app in-depth. The battery app is so full-featured that it demands its own video. One of the coolest features is built-in cell capacity benchmarking. So, I gave that a test with a 600-watt space heater load. Then, I uploaded the results to the SFK website so they could be viewed.

Part 3 Teardown – SFK 300Ah Review

In part three of my review, I disassemble the HP-Sk300 battery and give you a close-up look at the build quality, BMS board (Battery Management System), Heating Pads, and Prismatic Lithium (LiFePO4) cells. The cells turn out to be EVE Model LF304-V2. Overall, I’m happy with the construction, attention to detail,  ease of disassembly, and case design. It’s an extremely DIY-friendly battery.

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