10kWh LifePO4 DIY Battery Addition..... Here is my write up.

Markus Antonius · 29-11-2023 1:06pm

Deleted: just realise this thread about batteries

unkel · 29-11-2023 1:09pm

https://www.boards.ie/discussion/comment/121432498#Comment_121432498

Bought from midsummer several times over the years since they started here. Sound. It's a UK owned company though afaik and personally I would prefer to buy from solartricity.ie as it is an Irish company, but they no longer deal with the public unless you have an existing account

Markus Antonius · 29-11-2023 1:12pm

https://www.boards.ie/discussion/comment/121432507#Comment_121432507

Perfect thanks! Yes, I attempted to haggle them on the price of panels and they gave a quote for a lower price than what I actually offered :D

In my years of haggling, I was mystified on how to deal with this situation

So needed to do a quick check to see if they a bit dodge. Thanks!

uxt43 · 29-11-2023 10:25pm

after reading this thread, seems an major issue getting jk and solis to play together has anyone used the system on energiepanda (dot)com( sorry , I am not allowed to post a link, due to being new on the site) to communicate/ interface properly between solis inverter and jk bms? looks like a bit of setting up , but would be nice not to have to rip out the solis , or is there any other interface method that works these two successfully?

great thread by the way.

dermotx · 29-11-2023 11:11pm

I'm very tempted by this offer from https://eu.nkon.nl/rechargeable/lifepo4/envision-ess-72173207-305ah-lifepo4-3-2v-b-grade.html

I know they are Grade B but the price is amazingly cheap. It works out at 25c/kWhr with the €70 transport cost.

Is the only downside of B cells the lower number of cycles. Even if they were half the 6,600 I'd be happy.

Is it too good to be true?

Regards

Dermot D

unkel · 30-11-2023 12:17am

https://www.boards.ie/discussion/comment/121435450#Comment_121435450

Just very good. Not too good to be true 😁

NKON are a reputable seller and any EVE type cells I have ever seen tested, including B grade, pulled pretty much their full capacity in a standard discharge rate test as per the spec sheet

unkel · 30-11-2023 12:24am

https://www.boards.ie/discussion/comment/121435213#Comment_121435213

Not a major issue. Yes, the older versions of the JK BMS do not have on board CAN comms, but you can buy a little add on module from a third party to connect to it. I have one here, tested it and it is working fine. Or make your own, if you are handy enough with electronics.

The link has been posted more than once in the JK BMS thread, I think this might be it, but others correct me if I am wrong, I didn't buy it there directly

And the latest version of the JK BMS does have on board CAN comms, but it seems buggy, I wouldn't buy it myself until it is known to be working

dermotx · 01-12-2023 3:10am

Really great thread. I've read all 1,268 comments and hopefully have absorbed enough, certainly not all, info to proceed. I've ordered 16 B Grade 305AH cells from NKON and a bench power supply and the Load Tester.

I have a 3kWhr Solis hybrid inverter RHI-3K-48ES-5G which has a max charge/discharge current of 62.5A. My next purchase has to be the BMS.

Now from the thread there appears to be lots of difficulty with various BMS models communicating with the Solis inverters. Some people have been successful with the Seplos and others with the JK. On balance I think I'll go with the Seplos 150A 16S BMS3.0-Type-A since a lot of posters seem to use it here and there's not much difference in price between it and the lower amperage model and because the JK model "seems buggy" as stated by unkel above.

Then again, the Seplos seems to have consistency problems or have these problems been sorted out by the latest firmware?

What think ye? Solis or JK.

Thanks to all the contributors for all the knowledge and support on this thread.

Dermot

jasgrif11 · 01-12-2023 9:56am

Any concerns with battery temperature, given the current climate? My cells are spread over two shelves in my garage and are reading. 8 deg C and 12 deg C

graememk · 01-12-2023 10:15am

https://www.boards.ie/discussion/comment/121440878#Comment_121440878

Your fine.

Just don't want the cells being used when the cells are below 0

Scoobydoobydoo101 · 01-12-2023 10:52am

Apologies if a similar question has been asked before....

What options do I have if I would like to expand my storage?

I currently have 2 x 5kw weco (5k3) batteries working off a maxed out 6kw solis inverter (e/w).

I have plenty of space for more panels, inverter & batteries.

dermotx · 01-12-2023 2:48pm

https://www.boards.ie/discussion/comment/121440550#Comment_121440550

Sorry, that should be Seplos or JK, not Solis or JK😒

unkel · 01-12-2023 11:14pm

https://www.boards.ie/discussion/comment/121440946#Comment_121440946

Discharging below 0C is fine, but charging them will cause damage!

dermotx · 02-12-2023 2:58pm

Oops again. It should be a 3kW Solis inverter not a 3kWhr Solis inverter. Sorry for such a terminological inexactitude 😉

Ints · 03-12-2023 8:36pm

Hi guys, any thoughts on these? https://www.amazon.de/ECO-WORTHY-LiFePO4-Lithium-Motorhome-Complete/dp/B0CNVNS1T8/ref=mp_s_a_1_6_sspa?keywords=lifepo4&qid=1701631810&sr=8-6-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfbXRm&psc=1

I have solis hybrid 5kw inverter and not sure do I have to have another bms to run all of them in series and do I need braker and will my inverter charge them etc. So all and all have no idea what i am doing lol

unkel · 04-12-2023 12:16pm

https://www.boards.ie/discussion/comment/121450240#Comment_121450240

BMS unknown, cells unknown, you'd need to connect them in series, so need cables, etc. For similar money I'd get the Seplos Mason kit, a neater and most likely higher quality solution

Or for a lot less money, build your own. Back to post #1 of this thread 😁

SD_DRACULA · 04-12-2023 1:51pm

Can someone take a look at this 16s2p setup and let me know if the connections look right for splitting it into 4 rows of 8, don't think I can fit two rows of 16 like this one:

Not sure it looks right:

graememk · 04-12-2023 3:07pm

https://www.boards.ie/discussion/comment/121452516#Comment_121452516

The double bus bars are un necessary on the first one, where it jumps from one row to another. but otherwise ok

Second one is not right, there is 3 separate batteries there

Id do away with the double busbars between cells too,

Cant make a 4 row work without a joining cable, which i wouldnt want to do.

SD_DRACULA · 04-12-2023 5:14pm

Thanks and yeah I was thinking it was wrong alright. I don't want any other cables other than main + and -

I suppose I'm stuck for space need to get 2 BMS which I don't want if I can avoid.

graememk · 04-12-2023 5:18pm

https://www.boards.ie/discussion/comment/121453765#Comment_121453765

Suppose you could shelve them and use a copper bar to link the shelves.

spose · 05-12-2023 1:46am

4 rows should work with just the bus bars but you need to go up and down in your picture not right to left. Can pull out a picture later if that doesn’t make sense

SD_DRACULA · 05-12-2023 11:12am

https://www.boards.ie/discussion/comment/121455878#Comment_121455878

Go for it if you get a chance 👍️

chabsey · 05-12-2023 6:14pm

Apologies for the total newbie question, I have read a good few of the pages of this thread but am none the wiser so I'll ask and be damned. I am interested in getting a solar setup and adding batteries to it. Are what people describing in this thread attempts to charge these batteries off their solar arrays in a bid to potentially run as much of their house off grid as possible? I'm just asking at an extremely high level here, have no solar installed but this area does interest me.

Assuming I'm correct in thinking that's the aim, roughly what kind of money are you talking to achieve some decent level of off-gridness?

graememk · 05-12-2023 6:21pm

https://www.boards.ie/discussion/comment/121458544#Comment_121458544

Not off grid. And actually the benefit of batteries now is actually load shifting. Charge on nightrate and discharge during the day (and export the solar excess!)

What this thread has been about is instead of buying a battery off the shelf, Cells are bought bare, you assemble 16 of them to get a 48v battery and then connect that to the hybrid inverter.

But yes, in the summer you charge the batteries from solar, and let them discharge at night. But the system is grid tied. if you need more power than the solar and batteries can provide you take it from the grid.