Nice ?
Yes i agree its alot of current! I have some high quality 35mm2 battery cable doubled up to give 70mm2, so should cope ok unless a short occurs, but then thats what the fuse will be for.
Is the capacity controller on top of your bms part of the bms or a seperate unit? - do you use it to give a more accurate state of charge than the inverter or bms shows? Or maybe just to do a capacity test every so often?
And is that a shunt on the right hand side? - as thats something im considering if i cant get the (jk 200a) bms to show an accurate soc..
Im also considering fuseing each balance wire, im guessing there is no harm in this?
Really enjoying this whole solar system/battery building stuff, is an awsome project ????
Yes, was a very fun project, a whole power system upgrade for the Winnebago. Started out with wifey, "Can we get something to charge my laptop?" A couple of grand later we can surely charge the laptop. LOL
The digital meter is just that, a charge meter that I have since removed. I had not had experience with the BT apps everything comes with now, and that does a way better job anyway. Plus, where the battery ended up it's hidden anyway. I was also advised that copper lugs on alumium posts was a big no-no, so new primary cables were made with tinned lugs. That's when cleaned up the balance leads and took the meter off.
Yes, a smart-shunt on the right side, a master cut-off switch on the left side. The BT sending unit just above the smart-shunt. I took a chance when the Junctek smart meters were introduced, for a fraction of the cost of a victron, and turned out to work just dandy. Everything got moved from the original entry-step battery tray open to the outside, to indoors under the sofa. There's no acid venting with LFP like there is for flooded lead acid.
This is a 125A JBD (overkill solar) bms. My inverter is 600W, so the most I would possibly see for draw is about 75A. Once everything got hooked up I turned everything on that I could and checked everything with a laser thermometer. Nothing more than ten degrees above ambient. The BMS has a very nice app too, and both ambient and battery-mounted temp sensors.
You don't need to fuse balance wires - they are just sense wires, that's why they're generally about 24 gauge.
A bms is just okay for SOC. The problem is they report such by battery voltage, which can be all over the place, and they don't really coulomb count (although I've heard some say they do). Anyway, a smart meter is going to be WAY more accurate. For $50 or so the Junctek has been phenomenal, and it has a nice BT app as well.
More battery pics, and the smart meter in action. I have 430W of solar on the roof, and another 160W potable I can set out at camp. We only use about 100Ah or so per day/overnight, so this replaced a pair of golf cart lead-acid batteries. I have also replaced the 12V converter-charger with a smart LFP 120VAC charger from Meanwell. There is also a Victron Orion DC-to-DC charger that switches on when the engine runs.
Smart-meter app: