Poor quality control. The unit didn't work when it arrived, but I was in the middle of moving and packed it somewhere. After two years I found it and decided to reuse ultracapacitors for another project. During disassembly I found a cracked solder joint, so the positive pole was not connected to the circuit board, but only to the electromagnetic switch. Bad design, bad soldering, no quality control. After I soldered another longer connector it works fine. I can add a small switch to start the electromagnet so I can use it as a battery. By default, it disconnects the positive wire until it detects an inrush current from the starter, then trips to give a boost. Internally, the capacitors are charged to 16.4 volts, not 14 volts as the LEDs indicate, but it doesn't matter because the electric car never sees this voltage, it's pulled from the starter. So the reserve power you have goes from 16.4V to around 11V when it becomes inefficient and you need to recharge it. Clever idea, could be implemented better.
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