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

ducky1981

Hey does anyone happen to know if there's a way to reset or restore the seplos BMS to factory settings. I think it's my only option now at this stage as Iv tried everything else with it

ducky1981

It's ok now I think I have it sorted. The BMS was showing only 9% left and batteries was reading 3,40 or so. So I disconnected the BMS from the batteries and the inverter. Connected all back up and hey presto it's now showing 100% charged. So il see how it goes from here on in.

Thanks for all help

ducky1981

It's still not right. Iv the battery set to 200ah but under that it's got soc 75ah but I'm wondering if that should be set to 200ah as well or does that mean 75%.iv a picture attached

IMG_20221223_171333.jpg

spose

If you set the soc to 40ah then it should see it as 20% and then it won’t draw from the battery. When it charges it will keep charging until it hits the high voltage limit on a cell. It will then reset the soc to 100% and should work away from there

Geeyfds53573

10/11 batteries arrived @unkel @munsterfan2 as an fyi

championc

Mine (4 - all spoken for) showing for Thurs 5th currently

munsterfan2

No update on UPS label yet.

unkel

Yes mine departed Poland on the 22nd, departed from UPS sorting centre in Paris first thing this morning and should arrive to me on the 30th. In the meantime I ordered myself another 16, should get those in February for a total of 40kWh 😁

irishchris

https://www.boards.ie/discussion/comment/120040708#Comment_120040708

Now that is a serious battery setup. Was debating jumping to 30kwh on mine but 40 is impressive 😀

graememk

https://www.boards.ie/discussion/comment/120040742#Comment_120040742

Just go for the 40.you'll not regret it :D

unkel

I've already bloody ran out of battery today. Now that's exceptionally bad, usually I only just about don't make it. I average over 96% on night rate even in the cold period and that includes quite a bit of home / water heating with electricity.

2-3 years ago, when I bought my first 16 CALBs, 10kWh looked like quite a lot, upgraded to 20kWh before the summer, now going 30kWh and straight on to 40kWh. Might as well, because of the VAT removal, the cells are very cheap and keep their value well and they should last forever. Also a lot less worrying / micro-managing if you have a big pack. Nice to charge the car at full speed if you want without having to pay peak rates. And most importantly, no need to try re-educate the family to use electricity in a cheaper / more environmentally friendly way. With a 40kWh setup, they can all do what they want 😁

Nelbert

What size cable is connected to your inverter from your consumer unit? Without tearing ceiling or floor above to get to consumer unit I'm limited to a 6mm² or 10mm² connection feeding a sub board (waiting on electrician to verify size) which is fine for for connecting solar but my immersion heater in the heat pump is off this board so I'd be concerned about load every 15th night at 2am for the Legionella Cycle if it's 'only' 6mm².

Do you have multiple inverters to maximise charge and discharge rate from batteries?

320ah from PWOD looking appealing at the moment and I've been doing my research on seplos BMS etc so comfort level quite good there but my concern is the inverter. Likely go hybrid but already thinking about a second pack of 320ah to say goodbye to winter day rate but that's contingent on getting my head straight on current load and if I could have a setup to hit 6-7kw pull from batteries assuming heat pump and one other large load like oven or dryer going simultaneously.

Inverter I can see and control via Home assistant is my big thing. Bit I'm wrapping my head around the current required to charge 30-40kWh in a window period and making sure that any prep elec work is future proofed (i.e. 10 or 16 sq to a dedicated sub board possibly).

Geeyfds53573

What would be the suggested approach for adding a second set of CALBs 10kWh to the existing 10kWh. I have the Neey active balancer and am time poor.

Use inverter to get second set near the top and complete top balance of the second set with a charger. Add to first set when first set fully charged and let balancer do its thing. Is there a need to top balance the 32 cells together?

Could I just assume new batteries will be approx 30% SOC and put all 32 together when existing set is also 30% and let the balancer sort it out?

graememk

https://www.boards.ie/discussion/comment/120043577#Comment_120043577

I'd top balance the new set, fully charge the current set as high as you can, and then shuffle them connect the neey and work on.

Geeyfds53573

https://www.boards.ie/discussion/comment/120043596#Comment_120043596

Brill thank you was aiming that way

unkel

https://www.boards.ie/discussion/comment/120043596#Comment_120043596

My plan too. This will minimise disruption, so minimise battery time offline, so minimise losses too. Will get my cells tomorrow.

johnbk

Have been following this post closely for weeks. Ordered 280ah batteries from pwod store on 8th Nov, came today by UPS. Packed superbly. All tested 3.29v. Have them top balancing/charging now at 10.2 amp. Had to improvise with second bus bar and flattened some half inch copper pipe. It will take days I think to fully charge at this rate. Once top balanced, will test each cell. Really am hoping that I get close to the 280ah as I am keen to progress with the build. Have to say, I wouldn’t take this project on only for the information here. Might be slow to reply to questions but will update here as I progress.

johndoe11

Hi all, great thread that has got me thinking I should cancel my off the shelf 5kw battery which is due to be installed in February. I am planning to install a 8kw east/west system on my shed with a solis 6kw hybrid inverter. The cable from the shed is 6mm2 (buried in the ground over about 25m distance), which i am told is adequate for the install, but wondering if this is a limiting factor expanding the battery shorage to 10kw/20kw in the future? What could i expand the battery storage to with this cable? It will be quite a job to upgrade it, but would be easier now before the installation takes place.

championc

Capacity (kWh) is completely different from charge or discharge rates (kW). So you can add 50kWh but you will still only charge and discharge at the rate permitted by the inverter

unkel

Nice job @johnbk

Say the batteries were already maybe 40-50% charged when you got them, then with a 10A charger it would take less than a day to fully charge, so not too bad. Some of us only have a 3A charger. Not me, I also grabbed myself a 10A one recently on adverts for €35 😁

SD_DRACULA

https://www.boards.ie/discussion/comment/120044627#Comment_120044627

6mm2 is standard for this Solis setup, I have the same cable and as @championc mentioned the inverter is the limit here which is 6kw and even less when running from batteries only because Solis only pulls 5kw from the batteries for about 15 mins then goes down to 3.6kw

https://www.boards.ie/discussion/comment/120044515#Comment_120044515

What's the total capacity of the batteries? Got 16 of them?

Curious of the real capacity as these cells do take less room than the usual cells everyone goes for. Let us know.

johnbk

30 hours into charging and cells are up to 3.33 volts. Was second guessing the charger so took off a single cell this morning. It fully charged to zero amps and the 3.65v in around 2.5 hours. Next step is to take in the single cell inside (a warmer circa 20c) and charge again to be sure and then put on the tester. Fingers crossed. At the same time I’ll put the 15 back in parallel and wait (circa 45 hours) patiently until all fully charged. Alternatively, (as I’ll have to top balance again when testing is complete) I could charge one cell at a time while testing a cell. Kind of knew it would be slow watching Will Prowse on YouTube.

johnbk

His idea of setting up 4no 12v batteries for the purpose of fast charging is interesting. Would the 16s Seplos bms work as a temporary 4s bms?

Big Lar

https://www.boards.ie/discussion/comment/120046056#Comment_120046056

If there is and additional say 2.6Kw coming from the solar panels plus the max 3.6kw from the battery would the solis inverter then supply a continuous 6Kw ?

johnbk

This is proving a little more challenging than I had hoped. Finding it best to charge individual cells rather than all 16 in parallel. I can’t get them to 3.6v as the amps drop off to zero before they get there. The power unit is set to 3.65v. I am getting them to just over 3.5v. It takes many hours per cell at 10 amps to do this.

The first go at testing a cell didn’t go well. Cables supplied with the tester heated up (way too small) and had a terrible voltage drop. I couldn’t get it to stabilise above 4 amp. Tester low voltage protection is set at 2.6v. When the cell drops to this, the test will end.

I have upgraded the leads now to 4mm sq. I have also set up a heated space to keep the test close to 20c. I also have moved the other cells waiting their turn into the house so they have time to get up to 20c. Just started the test again. Have 10amp pulling now and just passed 1amp hour.

I really want this to work but the jury is still out for me.

Ps the clock on the thermometer is an hour fast

championc

If you want to just top balance cells, I just did them all one at a time, to over 3.60v, and left all sitting and confirmed as holding 3.6 before then building the string

slave1

I did mine in series, 8 at a time (I’ve 32) and they are currently sitting with 4mV difference

SD_DRACULA

https://www.boards.ie/discussion/comment/120050289#Comment_120050289

Yup

graememk

https://www.boards.ie/discussion/comment/120052415#Comment_120052415

Your probably dealing with voltage drop on charge too. I ended up using 10mm2 to charge mine (but I had it lying around)

slave1

car Jump cables will do it too