A simple question: I have a Smart Battery Protect (SBP) on the charge side of my Lithium battery, driven by a SmallBMS. Should I connect my MPPT 100/50 through it, or directly to the battery? I am concerned that the SBP won't allow current backwards, so the MPPT will shut off entirely at night (presuming no other charge sources). I do intend to connect the alternator thru the SBP, also the AC Charger.
So you have the output of the MPPT going to the SBP, then to the battery? That should work. I've been told that the mppt shouldn't be damaged if the MPPT is disonnected from your battery. As for alternator charging, you can't just use a normal relay or cyrix as that WILL introduce reverse current. If you have an orion smart DC-DC charger, you can just use the remote terminal ports to turn off the DC-DC either from the BMS or you can wire it to the SPB to turn off the DC-DC. As for the AC charger, what ac charger do you have? If it's victron my guess it would be safe to run it through the battery protect, but I'd double check with Victron and see if that's supported or if it will damage the charger. If it's another brand, same question to them.
Thanks! The AC charger is a ProNautic 1250P - I suspect it wouldn't have any issue with not being connected to the battery initially, and it has a Lithium profile available. Its been running the boat for the last few days as I've been rewiring and I have disconnected the start battery (all we have left!) a couple of times. I will try it on the "In" of the SBP initially, I can always rewire it to the other side if needed,
