Warpspeed
Solar Wizard
What you say is true, the problem is that a supercap can only source current by allowing the voltage to fall.
And that drop off in voltage can be pretty fast, it only works if the expected current surge is relatively short in duration.
A battery on the other hand, will have an initial drop in voltage under load, then the voltage remains relatively constant for an extended period of time. Supercaps are much better suited to very short surges, fractions of a second stuff.
And two batteries will not share the surge equally, because the resistance of the long cable limits the available current from the far battery.
Current will split in inverse proportion to the series resistance of each battery. The battery at the inverter end is going to get hit with the greatest part of a high surge, even if its only a relatively small battery
Starting motors up under full load can involve surges lasting several seconds, and that is the problem being discussed here.
Either solution could be made to work, if the supercap or battery is made sufficiently large.
Its just that for a two second long surge, a battery would work out to be a far less costly solution.
And that drop off in voltage can be pretty fast, it only works if the expected current surge is relatively short in duration.
A battery on the other hand, will have an initial drop in voltage under load, then the voltage remains relatively constant for an extended period of time. Supercaps are much better suited to very short surges, fractions of a second stuff.
And two batteries will not share the surge equally, because the resistance of the long cable limits the available current from the far battery.
Current will split in inverse proportion to the series resistance of each battery. The battery at the inverter end is going to get hit with the greatest part of a high surge, even if its only a relatively small battery
Starting motors up under full load can involve surges lasting several seconds, and that is the problem being discussed here.
Either solution could be made to work, if the supercap or battery is made sufficiently large.
Its just that for a two second long surge, a battery would work out to be a far less costly solution.
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