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

championc

https://www.boards.ie/discussion/comment/119796130#Comment_119796130

But was it only one cell ?

I did find myself that on my first round of charging, the cell settled at around 3.4v. I had to recharge again to 3.65v to then get it to settle at around 3.61v.

When I did this with all cells, I definitely got extra capacity (when I previously felt I was only getting maybe 6.5kWh or so)

But it also shows that OYE and PWOD are really the only ones to order reliably from

munsterfan2

From earlier posts, all cells failed capacity tests, all were between 125ah and 150ah. Ended up running the battery as at 120ah capacity for about 2 months when one of the cells started spiking / dropping under any charge / discharge load. Noticed none of my cells had a QR code on them, might not mean anything. Went through the whole back and forth with OYE store, they just drag it out until you go away.

There have been quite a few on here with issues and I wouldnt recommend anyone to buy of OYE (or PWOD as it appears they are same store)

E30M3

https://www.boards.ie/discussion/comment/119796337#Comment_119796337

+1

I found they string you along until you go away

unkel

Trick is to test anything you get from AliExpress within the allotted time for delivery (and do not confirm receipt until you are happy the product is good). Anything not right, raise a dispute and AliExpress will always side with the buyer, not the seller. You might have to upload video evidence of the problem and sometimes it takes a lengthy exchange to convince them, but I have been refunded every single dispute. And there have been dozens of them.

Once the product is fine and you confirm receipt, you're on your own. Forget about following up on any warranty if the product goes faulty after a few months. You can try, but they know you don't have a leg to stand on. They might offer refund if you return it (which costs more than a new item or is simply impossible / illegal as with batteries), they might offer to send you a new one for free (but you have to pay the postage costs which is more than it cost you new), etc. etc.

BuzzFish

OP back again.

TLDR: don't buy from OYE store

Just to update that my 16s OYE cells are giving me a max 120ah on multiple cells. I had top balanced and got about 100ah so I bought a discharger and bottom balanced each cell individually, which helped a little. That was a couple of months ago but still issues with 3-4 cells who top out at 120ah. Also, if demand is high (say 2500w or 50amps) my weaker cells bottom out way too fast and my pack dives from about 25% very quickly. Slow draw, pack gives about 6kWh but with any decent draw around 25% it dies, giving about 5kwH. I also charge at 1000w overnight to try feed the pack more slowly than dumping 3000w in and causing cells to race ahead.

OYE are no help at all.

johnbk

If I select the 16pcs 280ah lifepo4 from OYE store on AliExpress , it’s €3000! The price from Nkon in the Netherlands, is €2884. Checking on YouTube and on here, there is mixed results getting lifepo4 from AliExpress. Am I missing something?

Also, contacted Seplos directly about 16s 150A BMS. It is $242 delivered inc lcd screen but not the usb adaptor.

Maybe the prices from China are going through the roof?

Also handy link for calculations

https://micropowergrids.com.au/Calculators/1_LiFePo4_Battery_Calculator.html

con747

https://www.boards.ie/discussion/comment/119830265#Comment_119830265

I seen a post on another thread about this fella https://www.donedeal.ie/tools-for-sale/brand-new-lifepo4-solar-battery-51-2v-14-5-kwh/32533743?campaign=23 I have no Idea what the quality is like but he seems to do full ground mount installs as well as a range of batteries.

spose

I would get the USB adapter before the lcd screen. LCD screen is really of limited use. Is that €3000 before you add it to you cart and the VAT comes off or after?

Geeyfds53573

11/11 sale is on at the moment and it will be the cheapest price on Alibaba this year - All I know about the 280Ah is that OYE have stock in their German Warehouse - should be about 2k normally the vat gets deducted after you click through if ordering from China but I think that price should be cheaper alright but most here bought the 200Ah link back a few posts.

Seplos BMS a very good price at the moment through this company on Alibaba I know some bought successfully from here I went direct to Seplos so can’t comment

https://a.aliexpress.com/_mt0jdoY

€169 buy your own cable

poker--addict

Batteries in transit, about to order everything else I need.

On the BMS, have seen a few posts and video about the ability to auto balance, which I understand is part of some BMS? But not the seplos?

johnbk

I see that now, just at check out Vat is removed. That makes a big difference.

johnbk

Plan is to get the solar up and running this side of Christmas and go at the battery in the new year.

Looking at a 16pcs 280ah battery with Seplos bms - along with 25mm cable, material for making a battery box and other bits and bobs , should be able to keep it well under €3000 for a 14.4kwh battery. Does that sound about correct?

graememk

https://www.boards.ie/discussion/comment/119830561#Comment_119830561

All bms do balancing.. but all bms are the same, it's only a trickle balance.

To balance at any decent power, you need an active balancer eg a neey.

Or just top balance before building, the bms's can keep it in check then.

unkel

https://www.boards.ie/discussion/comment/119830643#Comment_119830643

Yep, I checked earlier this evening and 14kWh in 280Ah EVE cells costs about €2100 delivered, so add a few hundred quid for BMS, materials for your box, cables, extra busbars and it will still be well under €3k

championc

Be aware of

A) The 200Ah CALB cell casing is different and far more rugged than the 280Ah Aluminium cased cells

B) PWOD are a very reliable seller. I'm not as convinced with OYE (and I firmly believe that they are different entities). Capacity of cells from OYE is questionable based on several reports, which I don't think can be said about PWOD

JHet

https://www.boards.ie/discussion/comment/119831087#Comment_119831087

I spotted these for even less than that @ circa 1950 after the vat reduction

https://www.aliexpress.com/item/1005004870801157.html?spm=a2g0o.store_pc_promotion.promotePruductList_2004047525102.8

Are they the correct EVE's though assuming you want a 14kWh?

johnbk

Thanks for the quick replies. Very reassuring with all the experience on here.

poker--addict

https://www.boards.ie/discussion/comment/119743041#Comment_119743041

@graememk this is what I was referring to in terms of active v passive balancing, youtube video unkel shared. I guess this may be additional to the BMS rather than part of the BMS? Seems only logical to get one of these?

unkel

https://www.boards.ie/discussion/comment/119831501#Comment_119831501

Yes I can see no reason not to install an active balancer as well as a BMS. Would result in a labyrinth of "balance" wires though 😂

poker--addict

What about the combo unkel?

BMS and Balancer – the Off-Grid-Garage

Jk Bms Active Balance Bms 8s 12s 13s 14s 16s 17s 20s 24s Smart Bms 60a 80a 100a 150a 200a 600a Lifepo4 Li-ion Lto Battery - Battery Accessories & Charger Accessories - AliExpress

unkel

https://www.boards.ie/discussion/comment/119831973#Comment_119831973

Dunno. The cheapest one that can do 2A is €122, I'd have to see some reviews, but I wouldn't be rushing out to buy one anyway

I just got my NEEY active smart balancer up and running today and it can do 4A and cost me €120 (your man from your link is raving about it - and rightly so)

Balancing is important. But most other functions a BMS has can and are done by the inverter anyway. I've had some not so great experiences with the Seplos BMS myself, we just couldn't get on (and it can only balance at 0.1A or something like that, while just wasting / burning off the higher cells)

And if you're not into monitoring, an active dumb balancer is your man. I had mine for a few sitting on the shelf, cost me €35. Only installed it about a month ago and it works brilliantly, also balancing at 4A and actually taking electricity from a high cell, storing it into a capacitor and then charging a low cell with it.

poker--addict

OP bought a 4 pole, linked below. But said it was an accident but worked…what is the correct thing to buy?

poker--addict

Is the BMS in OP the standard one at this stage or have boards decided something else is worth using.

16cells going to be linked to 6kw solis

unkel

A lot of people here use the Seplos as in the OP, there is a dedicated thread for it in the forum. You will have to use a BMS that can talk to your inverter via CAN if you want the BMS to control the inverter and do home automation with it. But the Seplos is sh1te at balancing, so you will want to top balance your cells before deployment (this can take at least a week, easily double that with a 20kWh pack) and do a top balance once in a while after (maybe once a year, again this will take a long time and you will have to completely dismantle your pack and put it back together again after). Also the balancing is done by just burning off the highest cells, which is a waste of energy. I didn't like the Seplos, we couldn't get on (mostly because my inverter had a fault) and I don't have the patience to do top balancing

You could of course have both a decent cheap BMS like a Seplos and also an active balancer, lots of wires then though LOL!

johnbk

This is a very helpful thread and thanks to those that are sharing their knowledge. I have made the purchase of the cells and bms as highlighted/suggested a few post back on this thread. Just have to wait for delivery. Thinking now about balancing and testing cells as soon as they arrive. I was watching YouTube videos of this. Would this (below) be a better investment than a charger as I think it can do both the charging and discharging. It doesn’t have much options/settings on the charging front so maybe not. Any opinions would be welcome.

https://a.aliexpress.com/_mPQdRjS

unkel

Did you see the shipping costs?

championc

There's a lot to be said for whacking them straight in and buying a 4A Active Balancer which Unkel previously posted about

johnbk

Very interesting point. Have not seen too many negative comments on pwod or minerals stores that are trading on AliExpress. Neey 4th gen active balancer along with siplos bms would save a lot of money and time and worth considering.

by the way, in addition to Will’s diysolar, these are the other two channels that I have spent hours watching.

https://youtube.com/channel/UCEW1Dv7_YieagyEvxUpL10Q

https://youtube.com/c/OffGridGarageAustralia

poker--addict

Getting the 4a active balancer ordered today.

probably go with seplos BMS just because there will be more familiarity and help from boardsies but before pulling trigger is there any other BMS I should consider- I’m all for user friendly/simplicity.

Geeyfds53573

In relation to an Active Balancer is it ok to leave them permanently connected and would you really need 2 for 32 batteries