Solar PV battery options

DrPhilG

Also there's this notice:

With OYE they stated that the cells were shipped from Poland and all duty was included. This seems to indicate that I'll be liable for the vat on import.

DrPhilG

I wonder if a Northern Ireland delivery would be any cheaper or easier re tax.

graememk

https://www.boards.ie/discussion/comment/120045237#Comment_120045237

NI Is technically EU customs wise.

The Cells i got in April & Nov both had the VAT reduced at checkout, but landed without issue, the ones that were got on 11/11 seem to be landing fine.

Keep a watch on the prices, I did see 1400 last week for 16. (at checkout)

unkel

I paid €1364 on the 23rd. That's with the VAT taken off, but hopefully not charged upon delivery - like all my other CALB deliveries from PWOD before 😁

noelocon

Anybody have any advice on what off the shelf 10Kw battery system to get if I already have a Sofar Me3000. I HAD a diy setup (16s 200Ah) until recently but alas something shorted when I was wiring the bms and the entire thing sparked up and a number of cells caught fire. My better half has (rightly) put her foot down and now wants something non-diy for storage.

unkel

https://www.boards.ie/discussion/comment/120050152#Comment_120050152

😮

Did you not have your spanner taped up? Glad you're ok and I can see where she is coming from. Sorry, have no advice on pre made packs.

DrPhilG

Bloody hell.

What kind of cells did you have? I thought LiFePo4 was damn near unburnable?

noelocon

Yea I got them from Ali last year. No idea what happened tbh as I had just turned around and it started sparking and then boom. No tools or anything near them at the time except for the bms cables that I was wiring. I'd just top balanced them but there was still .3 of an amp to go before they were full. What's even stranger is that three of the cells went up and then the fire damaged a few more. It was all over in seconds but no idea what the root cause is.

Update: actually from looking at the burn marks I wonder if the bus bars were the cause.

graememk

https://www.boards.ie/discussion/comment/120051843#Comment_120051843

Dead short.

The copper bus bar burnt out, stopping the short. (1000A slow blow :P)

edit:

Also Id say you didnt have the busbars tightened down fully, hence the arcing and sparking.

That last bus bar joining the two sides on the the bms side shoudnt have been there. that was your mistake.

That is where your +ve and -ve to the inverter was meant to go.

cells didnt burn beacuse of over current, they burned because of the heat/arcing of the bus bars on the terminals.

championc

https://www.boards.ie/discussion/comment/120051843#Comment_120051843

You should only have used 15 of the busbars. You have one linking the two sides together at EACH end. So you made one big loop.

So in fact, it just shows ultimately how safe these cells are.

Geeyfds53573

Gosh yep you have joined up the main + and - - can the batteries not be salvaged

graememk

This was the video was looking for.

The amount of current a bus bar can carry depends on how tight the bolts are.

This is not a dead short though, but a full and empty cell:

https://www.youtube.com/watch?v=wUvfzDuRVtE

noelocon

https://www.boards.ie/discussion/comment/120052016#Comment_120052016

Shite....I was so focued on gettin the BMS wired that I must have put on that busbar by mistake knowing that the BMS leads were supposed to go there.

thanks @graememk it's good to know what caused it.

the question now is how do I determine if the batteries are worth salvaging

graememk

https://www.boards.ie/discussion/comment/120052078#Comment_120052078

You'll not make that mistake again!

Depends on if any of the bolts are welded in, Id say it looks worse than it is.

Look at the short circuit tests from gwl :

https://youtu.be/Qzt9RZ0FQyM?t=183

LFP just vent, yours didnt get near that,

What voltage are they sitting at now? Possibly some reduction in capacity due to the v high current but if are all reading the same voltage id say they would be fine, Id give them a wipe though!

noelocon

Yea they're all sitting at 3.31-2 volts. No swelling but 4 of them are heavily damaged.

I can get 4 new ones from Ali arriving in March. Is it possible to setup the existing 12 and use them or will the voltage not be enough.

championc

You'll really need 16 tbh, to also use and have the safety of the Seplos.

Get a brass brush or emery paper and clean up the terminals. Will a bolt screw into those connections ? Is the one with a bolt there welded into place ?

buzz11

https://www.boards.ie/discussion/comment/120051843#Comment_120051843

The jerry can & gas cylinder were ready for the mega BBQ !!

graememk

https://www.boards.ie/discussion/comment/120052359#Comment_120052359

Even a file to take the worst off it off.

If you can clean them up, I'd say they are useable.

15s is usually as low as you can go voltage wise but not sure if the seplos supports it.

Maybe some wd40 to clean off the soot.

championc

The plastic scorching could be purely cosmetic. The rugged plastic casing is possibly one of the main reasons as to why we have promoted the used of these 200ah cells over the other aluminum cased 280ah cells

slave1

https://www.boards.ie/discussion/comment/120052078#Comment_120052078

Thanks for sharing your misfortune, it’s a great learning for the community as a whole and you now realise what your mistake was. Stay with it and let’s see this pack rebuilt🔗

noelocon

So I spent some time going through the 4 most damaged cells and other than a few welded screws they seem ok. The concern I have is the state of the terminals as they're now not even and I wonder if that'll cause any issues as there's still melted metal on them.

All the threads seem fine though.

championc

Get a dremell or emery paper and smooth them off. They'll be grand 👍

DrPhilG

Lads we're missing the real issue here...

His missus laid the law down and told him no more DIY!

unkel

https://www.boards.ie/discussion/comment/120053614#Comment_120053614

His job to change her mind so :-)

Nelbert

Is it still DIY at this point? He's help from the experts here.....

Loopholes.....

graememk

https://www.boards.ie/discussion/comment/120053662#Comment_120053662

"learning experience"

Ive fried 1, maybe 2 balance boards.. thankfully they were cheap, so when it came to the bms.. the leads are triple checked. and checked again.

unkel

Nearly fried a cheap Daly BMS once. Balance connector started to smoke, pulled it out quickly. Got lucky. Indeed double and triple check the voltages now before I connect.

championc

https://www.boards.ie/discussion/comment/120053614#Comment_120053614

That was when he had no idea as to how it happened. But now he has the answer to that question.

But it also shows how safe the rugged casing of the CALB cells are.

ELM327

https://www.boards.ie/discussion/comment/120053816#Comment_120053816

Yes I think we all do that. I'm still learning (and have a lot to go!) but earlier in the process I blew up a cheap inverter. That was how I learned that VOC is different to the voltage under load.

slave1

When I was building my 32cell pack I made a real life sized template on a 2.4m length of wood, helped me get the BMS wires extended correctly and avoid accidently "mis-busbarring"

unkel

Programmed my inverter to not discharge my old pack this morning and when I had a look, all cells were fully top balanced by the NEEY active balancer with all cells between 3.651 and 3.653V, these balancers are super good and a bargain for what they can achieve in just a few hours

I was parallel charging / top balancing the new cells since last night. With 3 bench chargers 😂 but this was at least going to take another 4-5 days, so decided feck it, I will let the active balancer do its job so pack rebuilt with the new cells, so now have 48 (30kWh) with another 16 on the way from China for 40kWh. All fitting neatly into an old cabinet (with the back removed for natural convection and a couple inches away from the wall. Quite pleased with the result. Must make up some door / panel for the gap between the doors. Did a reasonable job tidying and taping the balance leads in place, will do a really good job next time as that will be my final pack.

slave1

"final pack" yeah, sure😶

unkel

https://www.boards.ie/discussion/comment/120065091#Comment_120065091

LOL yeah that'll be me finished. Every additional 10kWh adds less value. 20kWh wasn't enough. Needed the 30kWh and the 40kWh will give just a bit more buffer for all round less micro management, no need to train people in the house what to do, etc. I also do expect budget friendly V2H solutions will be on the market in a year or two - that would give extra storage for free as the car is there anyway

Couldn't resist the bargains, the last lot was again only just over €1300 with the VAT not charged. Really hard to go wrong for €130 per kWh for these super sturdy CALB cells

Final plans then are upgrade the Sunsynk to a 9kW single phase hybrid inverter and get 5kwp on my north facing roof (for total 16kwp), another single panel into my back wall string and eddi installed and outputting to immersion and storage heaters. Should all be in place before the start of next winter. Hopefully a lot earlier

unkel

Extended one of the doors. So all out of sight now

irishchris

https://www.boards.ie/discussion/comment/120064997#Comment_120064997

Looks good @unkel. Can the neey active balance be left on at all times and continue to balance on a daily basis at fully charged or@unkel is it a case of having to connect it and disconnect after doing the job and do the same again when want to rebalance?

Also are they usually around 100 euro as just had quick look at them there in alexpress?

unkel

Yep paid a bit over €100 iirc, was not in a sale and that included shipping which was pretty swift. A week or two iirc. You can get them a bit cheaper in the sale / if you wait for slow shipping.

These are smart devices, you have an app (Android, not sure if there is an iOS one, probably not) on your phone and settings you can put in. I've mine set to only starts balancing when one cell hits 3.39V, so in winter the battery charges up quickly after 15kW o'clock and spends the rest of the night balancing. Checked this morning and it had done a perfect job.

You are thinking of the basic active balancers, work the same but no settings, which means they are balancing all the time. At first thought that sounds like a great idea, but it isn't as not all cells have the exact same capacity, some are simply weaker. So go down quicker or up quicker. And you keep forcing them all the time, which likely makes them even weaker over time

Geeyfds53573

Thanks Unkel good to know I was thinking of skipping the top balance myself for now as have a Neey, there is an IOS app but haven’t used yet

unkel

https://www.boards.ie/discussion/comment/120066720#Comment_120066720

Ah good to know. There's usually some old no longer used Apple devices around the house - I never used them but the kids all do - and I find them handy for permanently displaying a certain app. They seem to stay on better / keep charged better than cheap Android devices. I guess because they were once very expensive! I have an iPad mini 3 - I think - above my desk permanently showing the myenergi app 😁 might do the same for the NEEY. Mind I bought a JK BMS in the 11/11 sale, haven't tried that yet. It can do 2A active balancing. I'll test it out on a test battery, main reason for installing it would be the comms - talk to my inverter via CAN. But not yet sure if / how that works / how to configure

And yeah top balancing in parallel is a complete pain in the hole. It would be tolerable if you'd have a 40A or higher charger (who does?), but still a pain. The balancer does all the work for you. Next time I won't even bother putting the new cells in parallel, just strip down the old battery and rebuild it with the new cells. I did put a sticker on the new cells though, so for each parallel cell, I used 2 old cells and then 1 new one. Got to give them a fair start. And of course monitor the progress. If you did this and had a BMS like the Seplos installed, it would throw a mickey fit, start crying, shout abuse about monomers at you and then shut itself down 😂

unkel

So I was expecting some cells to go high after an hour or two of 100A charging last night. And they did. I then just switched off charging at the inverter and let the active balancer spend the rest of the night balancing. Did a good job of it, but the battery was obviously not yet completely fully charged when I switched charging off. Will do the same again this evening. I've a lot more buffer now, so I could afford to not fully charge

graememk

https://www.boards.ie/discussion/comment/120068025#Comment_120068025

In theory, you should be able to drop the charge to 4 amps and the balancer should be able to shift the power about as needed?

irishchris

https://www.boards.ie/discussion/comment/120066577#Comment_120066577

Nice one, ordered one here last night so should be here in about two weeks. Assume these are wired similar to the BMS. Postive 1 and negative to first cell and then to each positive on cells after that up to 16?

unkel

https://www.boards.ie/discussion/comment/120068192#Comment_120068192

Yes exact same as a BMS. It's pretty clear / easy if you've ever done a BMS and pretty clearly labelled on the NEEY case itself as well at the connectors

unkel

https://www.boards.ie/discussion/comment/120068123#Comment_120068123

In theory. But I've two issues with the Sunsynk that have not been resolved yet even though getting the latest firmware. One is that I have no way of limiting the charging or discharging power (even though you specify it in the menu, you can even specify it per time slot - but this doesn't work). So when you charge from the grid, it charges at max power (about 100A) continuous.

HotSwap

So if I wanted to do a 10KWh battery; what do I need? Do you have a list of stuff I need to order? Are you guys hooking these up to hybrid solar inverters or dedicated battery inverters / charge controllers?

slave1

First post here ....

https://www.boards.ie/discussion/2058246061/10kwh-lifepo4-diy-battery-addition-here-is-my-write-up/p1

johndoe11

Been following this thread for a while, thanks to all the contributors. Getting a solis RHI-1P6K-HVES-5G installed next month with an 8kwp system. Thinking of cancelling the off the shelf 5KW battery and going down the DIY route. I'd have no issues doing the assembly work, but just concerned about BMS compatibility and what might be required there. What the best and easiest BMS solution for the solis? Is seems to be seplos, but just wondering if any other are suitable? I also saw ZEVA used successfully but they are no longer in business.

slave1

Folks, our Forum favourite PWOD have started putting in a minimum 180-190Ah disclaimer in their 200Ah AE ads😢, we might not be getting Grade A cells/full 200Ah capacity going forward

unkel

https://www.boards.ie/discussion/comment/120070383#Comment_120070383

I don't think we ever got grade A CALBs, thinking about it. Minimum of 180A is fine with me!

DrPhilG

Just submitted my meter readings for Nov-Dec.

Day units used - 134

Night units used - 1909

I was using electricity for heating a lot of the time to reduce my oil bill (which I did by about €150 a month).

So about 900 of that 1900 was load shifting with the other 1000 being actual night use.

900 shifted units at a difference of 19.5c is €175 saved over 2 months thanks to the 20kWh battery. Give or take for losses etc it's still substantial. Add in October, January & February when I'll still be load shifting 10-12kWh per day and accounting for the savings in oil and I'm pretty pleased with my ROI.

It's late and I'm tired, how's my math?

unkel

https://www.boards.ie/discussion/comment/120068269#Comment_120068269

For the record that works now, I can limit the grid charging rate in the Sunsynk. In the battery settings, not in the schedule though where you'd expect it as power is a column there