Idiot's guide to a self build battery

[Joeboy]

https://www.aliexpress.com/item/1005005789736951.html

Thanks Nowty, ordered a pair this afternoon. SWMBO's like 'are you going to disappear down the hut for days again'? I'm like....

Just one bit of advice, the split pin that goes into the handle is too big or the hole is not big enough. You might have to drill / file out the hole or squeeze the split pin a bit to get it in.

You do get two split pins though in case you feck up first one.

Cool, will look out for that, cheers! I'm.doing both poles and will board mount the isolators. Raring to go again!

[Andy]

Well, I'm joining in with some more banks in parallel. The shopping has started here as well. I've just ordered two JK BMS (JK-PB2A16S15P). I went for the active balancing so I don't have to faff around too much. Also they allow multiple banks of cells. I am adding 30x 280K with the Pylontech. I might look to go all 280K if it all goes smoothly. Unfortunately I have to send my Quattro of for repair, after exactly 1 year. I might delay sending it off so I can do the battery whilst the Quattro is offline. I have some questions for those more knowledgable.

My power shed is of course about 4cm too narrow to fit the 16 cells horizontally in a single row. I'm starting with 15S but probably want to go all 16S.
I've been struggling with room temperature gradients with the Pylontech arranged vertically. There was up to 12 degrees difference between the top unit and the bottom one. I have noticed the pylontech max/min voltage drifting apart over the last year which I was wondering if that is a temperature related effect. I've reduced the delta to 2-3ºC by have a powerful fan blowing the warm air from the ceiling underneath the Pylontech stack. I might need to move my SolarEdge inverter again which might give me the width I need. It's a bit of a squeeze moving that though with no obvious location. I need some serious thought on how I'll lay things out.

I have 4 sets of pylontech cables at the moment.There is no obvious point in reusing them without cutting them up. I'll be future proofing with 25mm cable. Does anyone have any recommendation for a reliable source of acceptable quality cables? I am working on them carrying about 141Amps in my shed which is about 20-30ºC throughout the year. I'll never need more than 120A I think. There does seem to be a lot of variation in figures given for what a wire can carry.

I was going to buy a battery tester which would double as a precharger. However after watching this video by Andy
I am thinking I'll just parallel up my two new 15s banks of 280K and let them level out over time. The BMS JK-PB2A16S15P is active so It can sort out any cell imbalances.... Or would any of you recommend charging all the individual cells so that at least they are matched in a bank?

[resybaby]

Love reading these threads about what you guys are all getting upto with your battery constructions, the help encouragement civility, skills understanding and great banter all mixed together make such things a pleasure to read.

I happily confess i havent got the slightest clue about what your all talking about, you guys obviously know your stuff, me. . . i struggle with putting aa batteries in a torch.

They say learning is sometimes a slow process, i take that to a new lower level with all this electrickery, but im slowly picking bits and bobs up so how about a few piccies mixed in for us mere mortals to stare at.

[Andy]

Love reading these threads about what you guys are all getting upto with your battery constructions, the help encouragement civility, skills understanding and great banter all mixed together make such things a pleasure to read.

I happily confess i havent got the slightest clue about what your all talking about, you guys obviously know your stuff, me. . . i struggle with putting aa batteries in a torch.

They say learning is sometimes a slow process, i take that to a new lower level with all this electrickery, but im slowly picking bits and bobs up so how about a few piccies mixed in for us mere mortals to stare at.

You've just got to dive in I'd say it doesn't take too long but it probably took me a year starting from zero knowledge to plan out the heat pump,solar and battery combo. Many calculations for thermal stores etc along the way before I worked out the optimum setup. New technology and external factors along the way has completely changed the best approach. For example, my Eddie will get very little use now as it makes no sense to use it Export solar instead. Thankfully it just about paid itself back.

Now I have Offgrid garage playing in the background constantly tanking notes as I go. It'll be no different to the process for the planning you did for your setup :p

[AE-NMidlands]

how about a few piccies mixed in for us mere mortals to stare at.

there are absolutely loads of pictures spread through the thread, e,g #709. Or you could run through a few of the pages chosen at random. It might help if you went to the start of someone's posts in this particular thread and read what they were saying about what they did and why in their successive posts. Once you have found an interesting post you can search the forum for their posts and follow that story.
People sharing their experience (and pics) as they work through a project can't really be expected to produce separate pictorial summaries as well!

[Joeboy]

how about a few piccies mixed in for us mere mortals to stare at.

there are absolutely loads of pictures spread through the thread, e,g #709. Or you could run through a few of the pages chosen at random. It might help if you went to the start of someone's posts in this particular thread and read what they were saying about what they did and why in their successive posts. Once you have found an interesting post you can search the forum for their posts and follow that story.
People sharing their experience (and pics) as they work through a project can't really be expected to produce separate pictorial summaries as well!

There are a shedload, start at page 1, make a cuppa, take notes. I personally continue to use the thread for reference. Gotta do the spadework though. It is a diy battery learning curve waiting for exploration.

[resybaby]

Yeah see the piccies that are out there on the threads, which is great and they do show a fair bit (wouldnt ever expect a pictorial guide - far too cheeky) as you guys say, its a heck of a learning curve especially piecing it all together when the 'language' isnt something ones familiar with. Im barely off the starting line with it all really but enjoying the journeymevenmif it makes the head wobble lots.

Limits on my battery knowledge currently is adding a new one to my current stack - which reminds me, im picking two more 5000's up from Voltacon in Coventry on Monday morning, ordered them the other day and managed to 'lose' the VAT. Wish i had the skills to make a bank up instead, but will have to stick with the 'plug and play' for the mo.

Keep sharing guys, much respect to you all

[Joeboy]

Yeah see the piccies that are out there on the threads, which is great and they do show a fair bit (wouldnt ever expect a pictorial guide - far too cheeky) as you guys say, its a heck of a learning curve especially piecing it all together when the 'language' isnt something ones familiar with. Im barely off the starting line with it all really but enjoying the journeymevenmif it makes the head wobble lots.

Limits on my battery knowledge currently is adding a new one to my current stack - which reminds me, im picking two more 5000's up from Voltacon in Coventry on Monday morning, ordered them the other day and managed to 'lose' the VAT. Wish i had the skills to make a bank up instead, but will have to stick with the 'plug and play' for the mo.

Keep sharing guys, much respect to you all

Nothing wrong with that (commercial battery units), built in bms, plug & play. The rest after that is line diagrams, a basic mechanical & electrical understanding and mucho respect for the arcing blue spark.

[AE-NMidlands]

I have decided that (although we have almost completely refitted our Victorian house) and I am happy doing plumbing, household wiring (when it was legal) and building, the reputation here of Pylontech batteries is testament enough for me to buy them in for my next phase. Regarding my phase 3... I wonder if I shall make it, possibly because of no actual need, or just Old Father Time catching up on me? Who knows?
A

[nowty]

Limits on my battery knowledge currently is adding a new one to my current stack - which reminds me, im picking two more 5000's up from Voltacon in Coventry on Monday morning, ordered them the other day and managed to 'lose' the VAT.

Is that one of those business to business transactions ?