Agreed. What are you running off of this battery bank ?
Bus Bar to Bus Bar Question
- Thread starter AlaskanNoob
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Agreed. What are you running off of this battery bank ?
AlaskanNoob
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800A to or from the eight batteries max (so 100A per battery) by their design and their cable limits.
My system limits me to putting about 65A to each battery unless I get more solar and I'm taking out even less than that due to inverter limits.
AlaskanNoob
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An off grid homestead. So everything that I can.
We're interested in the amps to each battery as that is probably a better judge of how balanced the cables are than voltage is.
AlaskanNoob
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I don't know that info, I imagine it would take an amp meter. Perhaps in the morning I'll kick on the generator so it's a steady input and see what the cables read.
It's very difficult to measure. From the time you disconnect a clamp-on ammeter from one cable to the next, something could change (state of charge, cloud cover, etc) that affects the amps.
I meant to ask what inverter and the peak power output of it.
Make and model should be enough info.
AlaskanNoob
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Victron Quattro 15K.
AlaskanNoob
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I'm now seeing a disparity in cell voltage of .008 but I have no idea if that is considered a lot or not. The BMS will throw a cell imbalance error at some point (I have not gotten the error), but I don't know what the delta is for that error since the manual doesn't specify. I'm guessing .008 isn't that bad. Hopefully the gap doesn't continue to grow larger.
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Suijkerbuijk
I cannot be held responsible for this information.
In my if thare is cell in balance error and only one cell is in that balance volts and the other not
I have that error ...i think that bms on that moment can not do a balance thanks to the other cell not are the volts start that it need to balance them.
I have about 230 errors logboek from one cell that do this.
And its on battery that have a inverter on it.
The second battery do not run a inverter and i do not have that problem .
Both battery are from the same series and same date.
So on cell hit 3.41 volts and the other are 3.39 volts and than i have a cell error.
Charger and discharge stay active .
But not always on a day i have a 100% full battery .
So i do not hit always that all cells go to over that 3.40 volts that it need .
.008 is often below the threshold at which the BMS will balance. On my JBD BMS the default threshold was .015. My new JK BMS has .010 as a threshold. The cells have to be above a certain voltage before balancing will commence.
AlaskanNoob
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Thanks, that's good to know.
AlaskanNoob
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Batteries came back to within .003-.004 volts so it seems cell balance shouldn't be an issue fortunately.
And the underground root cellar bus bar sits on top of the battery shelf...
Will put the front insulated panels on the front of the shelf when it gets cold and add a 12V bus bar to power some heater pads in the unlikely case they're needed, plus some fans in case there are any humidity issues (dehumidifier is keeping it 50% humidity in there now). Shelf has spacing ready for 8 more US5000 batteries which we'll purchase after this winter. Next step is to add the earthing to the batteries. Will just connect it to the galvanized steel culvert itself.
And the underground root cellar bus bar sits on top of the battery shelf...
Will put the front insulated panels on the front of the shelf when it gets cold and add a 12V bus bar to power some heater pads in the unlikely case they're needed, plus some fans in case there are any humidity issues (dehumidifier is keeping it 50% humidity in there now). Shelf has spacing ready for 8 more US5000 batteries which we'll purchase after this winter. Next step is to add the earthing to the batteries. Will just connect it to the galvanized steel culvert itself.
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I have been rather unimpressed with the Victron VE.Direct connections. I swear they pull out if I look at them funny. I saw one suggestion to secure them in the terminal with hot glue. I just use strain relief on the cable in such a way that there's some force from it to hold the connector in the terminal.
AlaskanNoob
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Are your connections mobile in your RV?
So far I haven't had that issue although I did have the A Can port in a Pylontech battery (that connects to the Cerbo) stop working and so the comms with my batteries all ceased and the MPPT wouldn't charge them. Guessing it was because the comm cable (unshielded) was touching a power cable and so maybe that fried it. Just switched the master to another battery and all is well now and I keep the cables separated.
Side note, just noticed you have a Polaris Ranger, have you looked into the Kinetic model by chance?
Yes. But even sitting here in my garage the connections aren't very secure.
Nope. Wasn't aware of it until you mentioned it. New name for their electric version.
Suijkerbuijk
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I use those cable on the mppt.
And compleet usb divice hang on that cable.
Than i life on a boat and that boat always go up and down with the waves.
And it still sit in one place and do not fall out.
It have clip that secure it .
Attachments
AlaskanNoob
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Yeah, it also has lithium. Test drove one, it moves quick.
featherlite
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It appears that the cables you are using to plug into your MPPT are DIY cables, with self assembled JST sockets, with "clips" on each side. My DIY cables were extremely difficult to remove after they were inserted into the MPPT socket.
However, my Victron OEM "VE.Direct to USB interface" cables fit into the sockets of my MPPT's fairly loose, and I worry about the cables falling out of the MPPT sockets as I bounce along in my cargo trailer.
I am stlll trying to figure out how to better secure the cables so that the cables do not fall out of the sockets.
robbob2112
Doing more research, mosty harmless
Get the victron wire box for that mppt, it has clamps to hold the wires in place and it shields the wires as well. Not very expensive and looks good
Suijkerbuijk
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Replace the victron oem connector
For a diy model .
And just only the outside of the connector by thake out the pins.
No wire cutting its the same metals pins inside.
Easy solution and for 5 euro done.
robbob2112
Doing more research, mosty harmless
Is it possible you used the wrong pin pitch... the JST connector comes in different pin size and spacing..and they look the same
featherlite
Solar Enthusiast
I just ordered one wire box for $31.83 (including tax). Thanks for the lead!
I have four MPPT's. I bought one wire box as a test. Not sure the box will fit over my 6 AWG wires.
To install the wire box, the wires and the MPPPT need to be unmounted from the wall in order to attach the wire box. I do not look forward to doing that.
featherlite
Solar Enthusiast
I am pretty sure I had the correct size JST connectors.
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