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Also totally off grid with the earlier version of the JK BMS 200a/2a and an Victron Multiplus II 48/5000, a smart shunt and 16s 280ah cells and was considering if I can get any benefits with this new BMS and couldn’t come up with anything major. You guys think I am missing something? What is...

A little update and some questions! 1. Got out to the cabin, and everything worked fine. The battery shut down due to low voltage in mid November, not odd, the sun doesn’t go over the horizon for my panels by then. Think we could have had snow too. Last year, the batteries had emptied. When I...

BTW the overall system looks really cool! Bet the cabin will be pretty amazing when everything is in place! ?

Instead of the battery meter and LCD displays I would recommend using a JK BMS for a self built battery which you easily can connect to a Raspberry PI running home assistant. You can then check it on the phone, stream the data to any display etc.

I built a 13.44 kWh battery with 16 x 3.2v 280ah cells from China (recommended seller from this place) without any prior knowledge whatsoever about electricity. Just watched a lot of off grid garage on YT. Works like a charm. Would definitely recommend that you built three packs like that...

But can that one charge a 48v battery? Seems like it’s high high V batteries only.

Had my dad been alive he would easily have filled this bad boy with LiFePo4s and an electric engine! ;)

Hmm, Yeah, and I will probably go with the MultiPlus anyway, because then I can just shift out the gear to my Off-Grid cabin out in the archipelago (I wonder how long away it is before EV boats becomes generally available).

Yes! So in that case I couldn’t charge the batteries with power from the Fronius. Getting three MPII 3000W/48 is about $1,500 more expensive than three Phoenix 3000W/48. It shouldn’t really be necessary to charge the batteries with AC from the Fronius, the Fronius will start about 2-3 hours...

After successfully building a system for my Off-grid Cabin based on 6 panels, a Multiplus-II 5000/48 and 16 EVE 280AH battery I have started to look into putting something on the roof of my house. I have picked the gear I am somewhat familiar with, and with the money adds up, I am thinking that...

When I use Victron's mppt calculator I get this suggestion: What I don't get is that when I do the math myself, I get the following result: 13.45A * 3 in parallell * 34,2 * 5 in series / 48v (system voltage) = I get 140 amps, and that is not even counting with the tempretur adjustments. The...

I have one question that I am struggling a bit with. In Sweden (don’t know how common it is) we have — as I understand it — three live cables with synched frequencies, a neutral and earth coming into a house. The stove and oven are three phase 400v and the rest one phase 220v (if this makes any...

I realize that I misunderstood your response when I wrote my reply above, I take it that you mean that I only should have a DC system and scrap the AC part all together (and not the other way around). Smart. I have snoozed this project a bit, but will start to with it now.

Kaleb is there any way to connect the SmartShunt directly to a RPI using Home Assistant? (ve.direct to USB cable) I've had two RPI's in my off grid cabin, one running Venus OS and one HA. But I just screwed up trying to update my Venus OS and can't get it to work (surely some crap with the...

30IS

Thanks!!! So how would you do it in my bunker? The only accessible area is the front, basically a door and the frame. Do you have a outboard tank connected to the fuel tank of the generator?

Yeah exactly, and when I googled some, I saw some discussion on the topic. Apparently the ‘resistance’ in an extension with a 90 degree curve is of course a little higher, but it was very very marginal which makes sense (in terms of %). Like how hard is it to blow air right out in the open vs...

I’ve built a little concrete shed/bunker for our old generator a few years ago. Even with a fairly effective pipe fan (183 m3/h) sucking air from high inside the shed and an air intake in the door (ie should get circulation) the generator didn’t quite get enough air. But it has worked perfectly...

Good point!

One important thing though, what got the MPPT charging again was (a) removing the communication cable from the JK BMS to an ESP32 that got was connected to a RPI running Home Assistant and (b) removing a communication cable from a 12v EPEver charger to the same RPI. The system worked fine...

Love the cell volt difference! Maybe this is the new way to balance the cells. Discharge them to 0.6v each in minus 20c, then let them be for a couple of months, then charge them up again! Sounds like a good idea @Will Prowse ? ? These LiFePo cells can take a beating. We have had many led...

Its charging!

It worked shutting everything off in the BMS, pulling the balancing cable plugs, and putting them back in. This is how the resistance looked in the summer: This is how it looks now: Do you guys think cell 2 and 3 are problematic?

Done charging for today, family is fed up with the sound of the generator, ran it for pretty exactly 10 hours at 28A. This is how it looks now: Do you guys think the 89%/remaining capacity of 249a figures could be accurate? This is how it looked during the summer: How do you restart the...

Aha, sorry, brain fart by me, didn’t figure out that the only one with a correct reading is 13 and the other are off when they are at zero… Thought 13 had issues.

No, it’s just an ordinary USB to USB C cable. When the power cable is disconnected, I don’t get any reading between the power cable and the smart shunt/or the 48v system, it just calibrates all the time. It’s the same when I measure towards an iron radiator in the room. I do get connectivity...

It is looking good in that there is a fairly consistent progress, have been charging for what 8 hours now: BTW, should I try to off-set the 13th balancing cable to get the balancing going? If so, should it be minus 0.048? It’s perhaps not that big of a deal.

Yeah, thinking about it, the last thing I got was a com cable for the EPEver (12v), that I connected to a home assistant RPI that also is connected to the communication port of the BMS, to be able to remotely monitor both the 12v system and the BMS. It’s not many days after I got that working...

Will do! I am charging now, but if I turn off everything in the BMS later, I should be able to check if there is any phantom currents later, right?

Yes, now, when the BMS is “open”, it’s just app 2.5-3v between the communication port of the smart shunt and (1) the minus pool of the battery, (2) the USB port of the RPI and (3) a minus pole of the 12v system. Yeah, how, when and where I don’t know. The 12v system is one option, it’s...

So the burnt cable before I pulled it (older picture) (ie the tiny cable hanging down from the SmartShunt): It goes from the communication port of the smart shunt to an RPI. The RPI is also connected with USB cables to the MPPT and the MultiPlus 2. The RPI is powered by my separate 12v system...

I fired up the generator which started the JK BMS. I am charging now at 28A, it was higher for a little while at first before I got to the settings, but not by that much (perhaps 50A). Everything is working, but for some reason the wire between the Smart Shunt and RPI burned up which was a bit...

I printscreened this in the summer, it’s 2.5v shut everything off, right? Maybe must get the overall voltage to 40v to get it to start…

The funny thing is, I can actually fire up the MultiPlus with my 12v system. A RPI runs on the 12v system and through a USB cable is connected to the MultiPlus with what is it called, V.Bus at the other end? When I turned on the 12v system the MultiPlus started… I would need to by-pass the BMS...

Yeah, problem is that besides the gasoline generator and a 12v car battery system I have no power out here. I will see what happen when the temperature gets up, but I don’t expect any massive change. I am going back to the civilization on Saturday and won’t be back until late June when I’ll be...