I want to see if anyone else has seen an issue with using the Smart Battery Protect as a charge protector as shown in the Multiplus II reference diagrams? My system is attached below. I have two SBP in the system. One used as a load protect and the other used as a charge protect. When the Epoch 460Ah battery gets low on charge, the load protect SBP 220 works as expected and disconnects the DC loads. However, at that point the SBP 220 used as a charge protect reports a short circuit and prevents the system from being charged from the MPPTs or the Orion-XSs. If I get the battery back to 30% charge with the Multiplus-II, the SBP 220 works as expected and I can then charge again from the alternator or solar. System works as expected if I bypass the SBP 220. I’m tempted just to remove the SBP 220 being used for as a charge protect permanently. I’m sure there is some odd relationship between either SBP 220 and the Epoch battery or Multiplus-II. Both are connected to the output of the SBP 220 through the Lynx Distributor.
Worth spending a bit of time with the online manual for the SBM. You can use it remotely switch the inverter if required. There is a high risk of fire resulting if used incorrectly.
“The Smart BatteryProtect is a uni-directional device. It can only deal with current in one direction, so either current to a load, or current from a charger, but not both currents at the same time. In addition to this, current can only flow from the IN terminal to the OUT terminal.”
I think you are implying that the IN/OUT are not wired correctly on the SBPs. If you look closely at the diagram, the DC load SBP has the OUT connected to the DC loads. The SBP configured as a battery protect has the OUT connected to the battery. Current flows from the MPPTs & Orion XS to the battery. This is wired as showed in Victron wiring diagram below. BTW, I’ve read the SBP, Orion XS, Multiplus-II, and related posts on this forum and google trying to find information on this topic. I’ve seen a few posts in other forums where people have had a challenge configuring the SBP as a charge prtoect and was hoping others on this forum could provide some pointers.
At this point I’m leaning towards removing the SBP. I’m just not convinced the SBP reliably functions as a battery protect in my configuration If you look back at my original diagram and the Victron diagram below, the Multiplus-II is directly attached through the Lynx Distributor to the Out of the battery protect SBP since both are charging sources.
Yes, indeed as the power flow is only ever in one direction. I typically only point out the most important things to consider as SBP was literally a “hot” topic a while ago. Are you aware of below?
“Choose the correct cable size and length to match the load. Voltage drop over a long or undersized cable between the battery plus and the SBP may result in a short circuit alarm when starting-up the load, or unexpected shutdown.”