KA Power 24V 102 kj 12 Cell Supercapacitor (19.44 x 7.75 x 8"", 34.5 lbs) for single start engines up to 32L.
They are easy to install and designed to exceed 1000 cycles, typically outliving the boats life. It's like having an emergency battery permanently on standby without any of the maintenance an actual battery requires. The supercapacitor replace the large starting battery bank, reducing weight and footprint in the engine room.
Recommended for constantly connected systems.