An electrical engineer has confirmed that my voltage drop issues (lights flickering, fridge compressor won’t start), stems from a mistake made by the marine electrican who installed a Smart Battery Protect. The out goes to a 400 amp fuse, which the inverter switch is connected to. See photo. The inverter switch is on the left side of the photo.
When I started the inverter, did it adversely affect the SBP? The fridge isn’t working and when the fresh water pump goes off, the lights dim.
I appreciate any advice on how to fix this.
A schematic would be helpful. Is the inverter just an inverter or can it charge the battery using shore power as well? How powerful is it, have you checked currents while the things are running? Looks like a BP-220, so a 400A fuse, and i suppose up to 400A of load, would be a bit much for it.
@lbayne Hello lisa, I dont know of your setup, but if you supect the SBP unit is faulty, just test the voltage across the two studs you can see with a multimeter. If you dont have one, you can buy a small one for quite a cheap price. Just set it to DC Voltage and touch the probes onto the two studs. If you see any voltage across the studs the SBP is either switched off by the BMS or it faulty.
If I did it correctly, both posts showed a little over 4.6 v. The Victron app reads battery status 13.37, load output state active, preset is 0, mode A, operation-normal. On the unit is 8.
The marine electrician who originally installed the BP last fall, just installed a new one a couple of months ago. He admitted to making a mistake with the current BP, which he will fix when he’s back from vacation. I was hoping to fix it now because the fridge isn’t running.
Thank you!
@lbayne the SBP is open circuit if has 4.6 volts across it. It has either been instructed to open by whatever is controlling it or it has failed.
If you need to immediately get your fridge to work simply remove the SBP from the circuit by moving both cables onto one stud. That way the SBP protect is no longer in the circuit and you can work out why it isn’t working later.
The 3000 watt inverter can draw 3000 watts / 12 volts = 250 amps and it is going through a 200 amp Smart Battery Protect so it has maybe caused the SBP to fail.
Whats the make and model of the inverter? It looks like it can switch over from inverting to shore power, the unit then also being able to charge the battery is not too far fetched. The BP would definitely not like that
This seems like a viable explanation. This is the second smart battery protect unit that the electrician has installed in a year. It sounds like he could be installing a third one this week.
Thank you so much for helping me to understand what’s going on.
The inverter is Renogy 3000 W. It Doesn’t charge batteries.
The switch controlling the inverter has been off as seen in the previous photo there’s still lights flickering and Fridg won’t run, which causes me to believe the battery protector is damaged. (?)
Thank you so much for the feedback.
I’m not one of the forum experts, so I hope I’m not speaking out of turn; but I thought that it wasn’t permissable to have an inverter on the output side of a BatteryProtect (because the inverter capacitor draws cause the BatteryProtects to fail). Could this be the problem?
From the BatteryProtect Manual: (Okay, I have to figure out how to add an image)
Okay, sorry but I can’t figure out how to add images. I was trying to paste in a couple of excerpts from the BP manual.
Basically, it says that it is forbidden to connect an inverter or inverter/charger to a BP via the “big cables.” It is okay to control an inverter’s remote on/off terminal via a small wire from the BP (but I don’t think the Renogy inverter has a place for a remote on/off wire to go?).
This info is on Page 4 of the Smart BatteryProtect manual.
Thanks, Dave. I haven’t yet figured out how to add an image.
I have a side question (for anyone) that I would imagine the OP might also have. I have an inverter (Xantrex 1500) that I used to have hooked up with my old AGM bank. Because of the issue mentioned above, I haven’t hooked it up at all in my new LFP setup.
This inverter DOES have its own remote On/Off switch (meant so that a person can turn the inverter on and off from a distance), but it is the flat type cable and hooks into the inverter with the “telephone type” click fitting.
I’ve have done some hunting to see if there is a way to convert from that “click fitting” to use that as the type of remote On Off terminal that Victron would want one to use (typically a little green two-position Phoenix connector and you put a single wire into it). I found someone asking the same question on the old Victron forum but there were no replies. I also didn’t find anything in a general web search.
I think the OP’s Renogy inverter may have the same type of remote On Off receptacle (telephone type click connector), so if this is possible it might help the OP as well.
About the Inverter problem I would suggest you try These guys as there are some very knowledgeable people there whom i am sure can help or at least point you in the right direction.
Sorry i can help anymore but someone else might know.
Dave.
