KA Power 24V 122kj 10 Cell Supercapacitor (19.44"" x 7.75"" x 8""), 32.5 lbs. 30V Max 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.
KAPower Supercapacitors Starting Module
KAPower Supercapacitors more info