How much DIY is worth it for a DIY battery?!

[NoraBatty]

Im about 1/2 way through the idiots guide for DIY batteries thread
Which seems to be more technical than my current ponderings, so apologies if included there, and for not adding onto the thread.

Ive spent the night reading alot, and looking online at various things.
I currently have no battery at all, so will be looking to install from scratch.
Installer lined up for the hybrid inverter, so that looks good to go.
Now turning my attention to batteries.

Fogstar do a DIY seplos mason kit, cells included as i am sure many of you are aware.
Roughly the cost is £2300 for 16 Grade A EVE lf280ks, plus enclosure. Apparently everything needed bar the leads to the inverter.

Trueer to the idiot thread, "DIY batteries" seem to have their own enclosures/rack, balancers/ bms, leads, etc made up, and import the cells.

The cells are oboviously the big expense, but how much is saved on the diy aspect of all the gumpf attatched to the cells?!

I am wondering if, it would make more sense buying a premade enclosure, like seplos masons, which it includes all the kit, needed so makes it even more idiot proof, and importing the cells.
This then acts as a half/75% diy battery, but neater than i could, or would, make myself, in what seems to be a trusted no frills package.

I had thought of about starting off with a 20kwh ish battery.
It seems if i buy an SM kit from fogstar, with EVE lf280k cells, assembly is required, but i can get 28kwh for around £5k.

From what i was able to look into last night, buying their enclosure with no cells,from fogstar themselves for around £400 per enclosure. Not alot of money when peace of mind comes with tried and tested stuff. This can also ve imported a little bit cheaper too.

I can then import 45kwh of cells, and source the premade boxes all in, for around the same £5k.
All ive done is shifted sourcing around, to increase my kwh yield by 14kwh, and cut down on what seems to be alot of work and time.

Have i missed something?!
Is making your own bms and balancers, and having even more of a puckered bumhole whilst connecting together, incase anything was forgotten, so much cheaper than buying an OTS enclosure for £300?!

Or is it the degree of puckeredness that makes the extra more satisfying?!

[Joeboy]

If memory serves, two Pylontech batteries would get you going and have bms built in. The bms will talk to the hybrid inverter. Adding for example 304Ah diy batteries and a balancer after that is quite easy. BUT, you really need to know what you are doing and be aware of the potential hazards.

Only you will know where your skill level and confidence are. A serious amount of money or e tra capacity can be bought in the diy route. Personally, I went Ptechs first then expanded into diy once I had a good handle on where I wanted to be.

[NoraBatty]

Thanks Joe.
Ive experience spinning spanners from an apprenticeship when younger, add that i am not the worlds most typical female, and relish a host of other DIY tasks, ive done similar before, with small scale boat wiring and battery banks and old school off grid lead acid battery banks powered by a genny for some serious allotment power.
Its not the same as playing with Lifepo4's, but im confident ive spent enough time around the sparky ends of batteries to be careful and safe. A registered spark, i am not though.

Having spoken informally to Craig, i need to decide what i want to do before we can move forward.
These 280 diy boxes come with 200a bms and balancer that will talk with most brands of inverter so im not sure the pylontecs would be needed, despite most likely having better kit.
I have given thought to doing it exactly as you say, more to get it signed off properly and up and running on the inverter side.it then leaves options of removing the bigger chunk and leaving the pylons if we ever moved.

Ive also been speaking to deriy who will get back to me with totals including shipping at the weekend, but are quoting $55 per unit, and docan.
Its docan who also do the seplos style 280 diy boxes, and have quoted me £4103 for 3 boxes with all the gumpf and 48 280ks ($60 per unit) shipped, which i think is pretty impressive in comparison to fogstar OTS.
Cheekily as deriy have quoted $55, ive asked if they can match it or do better.
Il hear back soon. I did stumble across colins email last night on the idiot thread, yet cant find it for the life of me to get a quote from him too.

It really is a decision on if the boxes are just bad value for the quality you get, or if going all in the diy route is better. A bit of self assembly is fine, and if it means i dont have to clear one side of the shed of moving boxes to get the mig out and weld some brackets, innorder to save £5, all the better.

[Andy]

colinbatteries@gmail.com

I’m just about to order another 48 direct from him

He also checks his pm’s on here.

[NoraBatty]

Thanks Andy. Where abouts are you?!
Ive sent him a pm.
I also want 48. Maybe we can link up.
Im in Aberdeenshire if thats anywhere near you!

[AlBargey]

Docan are risky, you may get grade A you may get fakes, it's luck of the draw.

Deriy I would be wary of for "A grade" at only $55 they'll probably be re-lasered / stickered barcode B grades.

But maybe you're asking for B grade anyway? Not necessarily a problem they could be B grade LF304's rebadged as LF280K's, but they can be B grade for many reasons, including out of spec self discharge, high internal resistance.. so it's a risk.

I would compare the Fogstar prices and ask Amy Wan from Luyuan for a quote of DIY boxes with JK Inverter BMS (Better than Seplos) and cells, it may take time for delivery but she's one of the few Alibaba sellers that get praise from other solar forums, I was happy: https://szluyuan.en.alibaba.com/?spm=a2 ... p_co.88.14

Here's my own build thread, it's for 24v batteries, but same principle and may also be some useful info in it:

https://camelot-forum.co.uk/phpBB3/view ... 085#p41085

[NoraBatty]

Al, thank you for thread link, looks like ive come to the same conclusions. Good to see yours worked out okay.

And thanks very much for the link, cheaper than i was looking at, and i like the integral breaker idea too.
Has the JK BMS fault been fixed now!
As Andy is ordering shortly from Colin, i am awaiting a message and will most likely go with him also, through peace of mind, and nice to keep contacts alive.
Given what you and others say, id rather pay ka known source for what im expecting, than be surprised.

If i am storing the batteries outside, to my mind they have to be in a suitably contained weatherproof shed/cabinet.
We have dogs and cats who get into the shed easily and mooch around, so really not keen on leaving terminals open or covering with a wooden box, that the dog can and probably will pee on if left to his own devices.
i dont like the idea of battery storage in wooden sheds, though i know people are happy to do so.
Ive got a ton of grp left over from boat repairs in the shed, so am going to be making a lockable, insulated grp electrical style cabinet for all of this to sit in outside, and site it on a concrete base.
That, plus the casing, with the worst bits shielded, its an extra level of protection from roaming animals, and wire loving rodents with big pointy teeth.

[AlBargey]

And thanks very much for the link, cheaper than i was looking at, and i like the integral breaker idea too.
Has the JK BMS fault been fixed now!

Thanks, no problem.

You'll save on shipping + handling if you buy everything from one supplier, so I'd do that if your thinking of DIY boxes and cells from China. Also you'll need to open a chat to get proper prices from Amy Luyuan or anyone on Alibaba really, shipping is often auto generated really high.

Re: JK BMS if you're talking about the new inverter BMS resetting the settings then yes it's been fixed.

You will probably want to get a heat pad or something and insulate you battery box for winter months too, but I just got a 230v 27w seedling mat which hardly uses much and kept my batteries at a constant 20-22°C over the last few months.

[NoraBatty]

Thanks Al,
Yes ive been opening actual dialogue rather than just going on their site rates, never afraid to speak to people, and always have questions.

Colin has come through with a decent price, so both me and Andy have gone with him now for cells.
I realise shipping would be cheaper from one source, but happy to spead it at such costs tbh, even if i could get it cheaper elsewhere.

Fiona Wu at Deriy got back to me this afternoon with shipping prices. $55 per v3 A grade 280k cell is confirmed, with proof given and photos of the QR code seeming to be straight from EVE and not the re lasered type.
It actually worked out £380 ish cheaper than Colin at $75.4 delivered, but, you never know until it turns up.

Im very happy with what ive ordered with Colin, and trust that he has a track record here, of being professional at all times, delivering with no surprises.

That peace of mind is worth £380, any day.

As for heating, im already ahead. I have an old extractor fan in the loft for cooling, and an old vivarium heater that ive already planned, with thermostat control plugs. Thanks for the tips though

[Joeboy]

Colin rocks, he's that guy you wished was at the other end of the transaction.



Well done btw, jumped right in eh?