Ronski's Solar & battery DIY build with whole house backup

Battery B is taking shape, just need to connect up the balance cables tomorrow and it should be alive.

Battery-B.jpg
 
Looking good, you have more Kwh than I have now!, my 20Kwh are looking small.

Van pack built and finished today, fitted to the van all good, left everything running over night (computer/fridge/router ect)
sunny tomorrow so that will sort/charge/balance the pack out.
Only thing left now is to add GPS to the VRM via the PI

Had to upgrade the software to access the new JK BMS, looks the same menu as yours now.
 
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Battery B is complete and alive.

Only problem now is I can't access the BMS for Battery A, I setup the new JK BMS, changed the pairing password and the settings password, went back to the other BMS and it asked me to pair it, every time I try, no matter what pin number I use it says it failed to pair, even checked my notes which said the pairing password was 1234 but that doesn't work either. Downloaded JK BMS App version 4.8.4.132 and still can't access the first BMS.

Only other thing I noticed was that battery B was only discharging about half the current of battery A, I think it just needs to fully absorb, can't find/think of any other reason why there's such a difference.

Battery-B-Complete.jpg
 
Hopefully just a glitch, it's the BMS access problem that's annoying.

No rodent protection, perhaps I should shut the cat in there. Apart from putting out some poison, which will also attract rodents there's not a lot I can do.

I had this issue yesterday, asking to pair and failing, I managed to fix the issue by deleting the app/rebooted the mobile/ installed the updated app from the play store.
(always had to side load the app before on android)

The 1234 key for pairing worked after this.
 
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I had to side load the new app - the one on Playstore is well out of date, I didn't try rebooting though. May try a different phone, just in case. The default pairing password is 1234 isn't it?

Apparently it is possible too get a temporary password, which works for 30 minutes, unless this is a pre-existing password no idea how they set it up as the BMS is not internet connected.
 
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I had to side load the new app - the one on Playstore is well out of date, I didn't try rebooting though. May try a different phone, just in case. The default pairing password is 1234 isn't it?

Apparently it is possible too get a temporary password, which works for 30 minutes, unless this is a pre-existing password no idea how they set it up as the BMS is not internet connected.
Yes, default for pairing is 1234
Default password is 123456

Version V4.13.0 from the Playstore, that is the one I now have working on the new BMS( JK-B2A8S20P)
in the van.

Edit to add.

The app is dated as updated on the 27th April 2023 in the Playstore
Think the app you have installed is to old, Playstore one looks to be 18 revisions ahead of the one you have installed
 
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Think the app you have installed is to old, Playstore one looks to be 18 revisions ahead of the one you have installed
Doh! You are correct, no idea why I thought the one I downloaded was newer, just uninstalled and installed the Play Store version. Not that it will make any difference, as I did originally have that.

PS That old app works with the new BMS.
 
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Doh! You are correct, no idea why I thought the one I downloaded was newer, just uninstalled and installed the Play Store version. Not that it will make any difference, as I did originally have that.

PS That old app works with the new BMS.

I was on V3.7.4, it worked and that was good to me :),Only updated as the new BMS was incompatible with my old version.
Think it only needed the newer version for the 4S compatibility, good now they have a good BMS that works on a 12v system.

On another note...... are you using Ruuvitag for Temperature monitoring ?.
My Victron Bluetooth one is giving me a lot of trouble, 3 times now it has just gone into minus temperature territory for no reason shutting the controller down, showed -18C last Friday!.

Thinking of trying the Ruuvitag as its compatable with the VRM.
 
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Bizarrely tonight I can access BMS A, it doesn't ask for a pairing password, but I've tried changing the password and it keeps telling me the old password is wrong, so looks like I'll still need a temporary password. I've currently installed the app on my tablet, and can access Battery B BMS via that.

I charged the batteries with 17.32 kWh in the off peak period - I set charging at 104A total - could go to 140A, but I don't think I need to, and I want to be sure everything was working OK prior to pushing 140A through the system.

Tonight I discharged around 13.16 kWh between 16:00 and 19:00, both batteries pretty much supplied the same current, some minor variation, but nothing to worry about, both pretty much showed the same SOC on their BMS displays as well, which matched Victrons SOC.

I checked the system for hot connections whilst force discharging tonight, the warmest spot was the busbar either side of my Victron rotary isolator, which was about 40c, this was with 140A running through it. These are rated for 275A continuous so it shouldn't be getting warm, so perhaps I'll have to pull it off and check the connections. Actually it seems perfectly normal https://community.victronenergy.com...itch-gets-too-hot-would-victron-switch-o.html
 
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My electrician is finally booked for next Thursday to replace the consumer unit, and sign off on the electrics they did for the solar install.

I also finally managed to get a temporary code from JK BMS via the Aliexpress store, what a pain that was given the time difference and having to work, and apparently the code only works for 15 minutes, but its done, and I was able to reset the pairing code.
 
Consumer unit was replaced just over a week ago, there were a couple of issues, kitchen lighting circuit was tripping the RCBO, and one of the rings didn't have continuity on the live circuit, well it did then didn't then it did - turned out to be an HR fault.

I traced the kitchen light fault to where an earth wire had crossed the neutral inside the outer sheath, and when the transformer clamp was tightened over time it had forced the earth to cut into the neutral causing it to make a circuit.

The ring fault I traced to a bad connection in the back of a double socket, luckily it was the forth one I checked.

Electrician came back yesterday, and all happy, so should receive the sign off soon.
 
I've actually been doing some more work on the battery system, need to get my battery heating sorted out.

I jerry rigged the system up over the weekend, just to get one working, to see how it worked and how it needed to go together.

You can see battery A warmed up a little around midday, so it does work.

I also need to get some polycarbonate sheets, to make a cover for the batteries, this will also help keep some heat in as well.

Battery-Temps.jpg
 
I've actually been doing some more work on the battery system, need to get my battery heating sorted out.

I jerry rigged the system up over the weekend, just to get one working, to see how it worked and how it needed to go together.

You can see battery A warmed up a little around midday, so it does work.

I also need to get some polycarbonate sheets, to make a cover for the batteries, this will also help keep some heat in as well.

Battery-Temps.jpg
electric blanket of some sort ..with a welders blanket on top ?
 
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@flea.rider The heat source is already built in (hence I was testing it in my post above - I just hadn't done the electrical side), the base plate for the cells is 10mm thick aluminium (effectively a heat spreader plate), stuck to the underside of this is two 24v head pads wired in series, so they can be powered by 48v.

The Victron Cerbo has built in relays, but they are only rated for about 1A at the voltages I'm using, so I use that to drive a solid state relay to switch the 48v to the heater pads.

I don't want to wrap the cells in anything flammable, so I'll make a case out of polycarbonate, and that should keep the heat in, if they do get a little cold then I'll look at adding some insulation, but space is very tight.
 
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It's actually surprising how little insulation is needed to keep them warm. My makeshift fire blanket and 50mm polystyrene enclosure has been on 3 weeks now and the batteries have only dropped below 20C once (to 19.5C) when it was 2C outside. They don't have any heating other than what they generate themselves and have been between 19.5C and 27.0C the whole time. A week before I'd had lows of 12-13C early in the morning.
 
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