HrKlev said:
datasheet that says "max PV short circuit current" 15A. Not quite sure what it means, but should be safe with a 3A fuse?
That amps rating means the input current is OK at 15A, lots of power since the input voltage is higher, up to (in theory) your maximum input voltage, W = V*A
Approaching that 100V limit on the input side can fry the SC pretty quick, so stick to say 90-95V max peak, even at low current levels.
The "real" limit is that the SC will not **output** much over 15A, so really there is no point in feeding much more power than what is required to get to that point (depends on the output voltage you set) V = W/A
The load (winch) is what determined the power drawn through the system, thus the amps, up to the 15A limit on the SC output.
> The winch will only be used whenever I get stuck, so not for long periods.
"Too long" could be 3 min, or 30sec or 6min
You need to measure the actual peak V&A with a wattmeter and compare to the 12V battery actual Ah capacity
assuming you disconnect the SC first to ensure the winch's draw doesn't overwhelm - that's where proper fusing will protect the SC, if you decide it's safe to allow it to support the battery, feeding an extra 15A from the high-voltage side.
Plus normal fusing against shorts, protecting the wiring from over-current.
Wiring should be sized for 20% above the max current you think it will ever see.
With the SC on fulltime while the vehicle is operating, it is powering the accessories, the battery will just sit floating, say 13.8V or whatever, at 100% SoC
Only after it gets somewhat depleting will the SC kick into higher voltage, actual charging mode at say 14.6V or whatever, and for lead 7+hours is required to get back to Full for longevity - so plug it in back home overnight as well if the high voltage side gets shut down.
Isolate all batteries when the vehicle is not in use.
Lead needs periodic topping up to stay at 100%
Conversely, LI needs to be stored at low SoC