Issue:
After working perfectly for ~6 months all of a sudden the Smart Battery protect is showing error E1: Short Circuit
In reviewing the Battery Protect manual it says
Under no circumstances is it permitted to connect inverters or inverter/chargers to a SBP via their DC inputs, a reverse current may flow that damages the SBP. In case you want to control an inverter or inverter/charger via a SBP, you must use the SBP to control the inverter or inverter/charger via its remote port. See example below.
I deviated from the above diagram and did not wire the Remote H to the MultiPlus, since I assumed BMS would control the inverter and SPB as properly wired. Is this not the case and I do indeed need another manual remote wire from the SBP to the MultiPlus?
Can folks let me know what I may have done wrong? I will be replacing my SBP with a new unit but want to make sure I don’t wire it improperly.
Your post is confusing, did you connect the Multiplus to the output of the SBP or to the batteries. Here is the proper diagram for a VE Bus BMS mk2 with Cerbo, Multiplus and SBP. You do not need the remote wire in this case as the BMS tells the Cerbo to stop charging or discharging and the Cerbo tells the Multiplus what to do via DVCC. If the Multiplus was connected to the output of the SBP then that is what you did wrong.
Inverters also have a very high inrush current due to the capacitors, which over time could damage a SBP. Even if it does not damage the SBP, when trying to start the inverter, the capacitors acts like a low resistance as they take the high inrush current and the SBP believes that there is a short circuit because of the high current.
If you did not connect the Multiplus to the output of the SPB then I have no idea why it has failed, the Multiplus should not have affected it. Have you anything that could have overloaded it on the outlet.
Thank you for sharing that diagram, that is exactly how my system is wired. All of my charging sources are on a bus bar before the SBP input as shown. (alternator, batteries, and multiplus)
Given this I’m not sure what I did wrong either. Perhaps the SBP just gave out. The only high draw device I have is a windlass which is why I went with the 200 amp SBP. It was also working fine for many months.
All my wiring is 1/0 and 2/0 and well within the rated voltage drop limits, so I’m not really sure what makes it think it has a short circuit. I’ve read a few reviews questioning the reliability of the SBP in general, so wanted to make sure everyone in my wiring seemed legit before I replaced it (out of pocket most likely)
You are not the first person to report failed SBP on the community that is feeding a windlass. I would question what sort of surge current a windlass can pull at start up as many motors pull 6 to 10 times rated current at start up. I have no evidence if this is an issue or not other than remembering various cases.
