diy solar

diy solar

Who has experience with (blue) aluminum cells in a mobile system?

I have the usual Aliexpress 280ah set-up and have put it through a torture test for a while now and it's the best purchase I ever made for the camper . In combo with the Overkillsolar bms probably have under $600. invested total compared to around $2700. for the Battleborn set-up. Of course money no object get the BB but I believe I get about the same functionality for a whole lot less.
A battery made from the 280AH Xuba cells takes up the same room as a USA group 31 battery. I would rather have two batteries made from those cells, than 5 BB batteries.
 

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Ok, another two days research, watching endless Victron videos, surfing the interweb, trying to sort the opinions from the cold hard facts.
Reached out to Victron supplier, no reply, nahda oh well.

So these are my current updated settings in the MPPT 75/15 and the BMV-712

With all these different devices attached, it's a bit confusing what's doing what, when and how.
Saw a "programmable" 200 amp BMS on UToob this morning, has a relay instead of Mosfets, looks interesting, but apparently not available at the moment.

Cheers
Tex
 

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If you are looking for a retailer with Victron support Peter Kennedy Yacht Services is a great one. No affiliation just a happy customer who has used them for tech questions several times. You can almost always talk to someone and email always gets great responses.
 
If you are looking for a retailer with Victron support Peter Kennedy Yacht Services is a great one. No affiliation just a happy customer who has used them for tech questions several times. You can almost always talk to someone and email always gets great responses.

I had a recent less than stellar customer service experience with PKYS. I will probably still buy stuff from them because they generally have good prices and free shipping, but if I needed support before or after the sale I would look elsewhere, probably Bay Marine Supply - https://baymarinesupply.com/
 
Thanks guys, but I'm in the great southern land.
I actually ran a Solar lighting company for 20 years, it's just that lithium batteries (and all their foibles) weren't around back then, in fact I suspect they were just appearing when I retired about seven years ago. So I am just trying to get up to speed on the fine tune settings in the BMV-712 of my van system.
 
Oh, and for what it's worth you can't set a "Charged voltage" of of 13.65 volts in a BMV-712! Even if you type in 13.65V it will increase it to 13.7V when you click ok. It's 13.6V or 13.7V. You pays ya money and ya takes yer chances.
 
Ok, so Daly BMS seems to have failed (discharge is ok, but no charge).
So, has anyone had any experience with these: https://tinyurl.com/5zhu83
I need a 200 amp BMS so choices seem to still be very limited.
Incidentally, due to covid the van has been living in the shed (no sun) and I have been just pulling it out once a month to top up the battery.

Whoops! How embarrassment as we say in Oz, turned out to be a blown solar fuse, strange seeing it was sitting in the shed?:)

On another note, I am loving my T-Rex electric jockey wheel, and I am now running it off my jump starter battery pack, keeps going forever.

Easy in and out of the (very tight) shed
Jump starter.jpgElec JW power pack (1).jpg.Elec JW power pack (6).jpgElec JW power pack (7).jpg
 
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Ok, listen up people!
Firstly the complaint that the BG-8S does "Not show correct state of charge on large cells", well I got caught out like everyone else, It's a no brainer when you see it. I, like everyone else had selected "Lipo" as my battery type figuring it was the closest thing to LiFePO4, what I hadn't realised even after months of mucking around with it that there is ANOTHER LINE below lipo! (scroll down). And guess what it is "LiFe" and just like that my BG-8S shows the the current capacity of my 200 amp prismatic cells pack perfectly!

Secondly, can it balance a 200 amp 4 cell pack, definitely, it takes about 1 1/2 to 2 days depending on the balance.
How do you balance, unlike the guy I saw on Youstubes, you should read the instructions, you actually have to push the middle button and select to start "Balance".
12 V x 200 amp LiFePO4.jpg
Thirdly, why do I have one? well as I have it prewired in parallel with the BMS connections, (white cables) all I have to do is plug it in any time to see the exact state of charge of all cells, handy to make sure your stoopid BMS (with no LED's) is actually working and not overcharging any one cell.

So now for my latest modification which is working a treat.
The issue was how do I keep the battery pack up when the van is living in the shed with no sun during Winter/lockdown etc.?
Well my Victron 15 amp charger came with an extra plug in set of permanent terminals, I had previously asked Victron if I could parallel those connections with the solar and they said no problem, which it wasn't with the old 100 amp LiFePO4 monoblock. However, since upgrading the system to 4 x 200 amp LiFePO4 prismatic cells and installing a BMV-712 it seemed to be overcharging (monitored with BG-8S) even though it was connected to the same terminals as the solar input which was a big concern.

So I had a little think about it and came up with a solution that works perfectly and cost nothing.

I put a two way centre tap switch into a small box with an LED, split the solar input to the MPPT 75/15 regulator to one side of the switch and the battery charger cable to the other. Keeping in mind the fact that a Victron regulator won't start charging unless the input is at least 5 volts higher than the battery, I found an old and old Hewlett Packard printer power supply rated at 18 volts @ 2.23A, I trimmed a 2 pin appliance AC plug to fit the plug wired to the box, and bingo! any time I want to top up the cells I just plug in the power supply and switch from solar to the PS, it all goes through the MPPT so no need to worry about settings or overcharging etc. It got a bit warm the first time I used it so I added a large heatsink with some thermal paste between, cool as a cucumber now. The LED is only lit when it's on the power supply, just in case.

Happy charging
Tex
 

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Ah, I see that listing has expired.
So here's the details:
Cole Hersee Model 24812
12V 225A Heavy Duty Solenoid
Brand new $75.00
 
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