Solar PV battery options

unkel · 19-10-2021 01:16PM

https://www.boards.ie/discussion/comment/118041078#Comment_118041078

I've seen plenty of reviews of various prismatic LiFePo4 cells from China and they typically exceed the capacity as per spec. Most reviewers get about or over the rated capacity out of them while discharging them faster than rated (which gives lower capacity), so all good really

That said, several actual battery packs (with built in inverter, BMS, etc.) are a bit optimistic. Simply don't buy these, just build your own...

reklamos · 19-10-2021 01:56PM

https://www.boards.ie/discussion/comment/118042190#Comment_118042190

The reason for asking is that I am looking to possibly build one myself. I also read reviews and unfortunately it is a mixed bag. Some as you say are good, others are mislabeled or do not reach the capacity. I was looking at OYE store in aliexpress but then I found people complaining that 200Ah cells were only getting up to 156Ah when tested from that store.

unkel · 19-10-2021 02:35PM

I wouldn't pay too much attention to some comments on AliExpress. Plenty of people don't know what they are doing and / or discharge at very high C ratings (like with a hairdryer / heat gun) so the capacity unfairly comes out lower. Have a look at some more knowledgeable YTers (and disregard any battery packs, just focus on prismatic LiFePo4 cells)

graememk · 19-10-2021 09:14PM

Was looking around to see if there was any other storage inverters about, Maybe with a bit more output power. As I know my BMS supports SMA, I looked into them.

Yeah.. the SUNNY ISLAND 4.4M / 6.0H / 8.0H supports 3-6kw discharge/charge rates. Found one website selling them. 3k+ delivered for the one that can do 5kw (middle one)

Oh theres another one, Sunny Boy Storage 5.0, which is only 2.2k.. ah its for HV batteries.

unkel · 19-10-2021 09:36PM

SMA have good stuff. I used to scour eBay, you will eventually get a bargain when someone has misspelled the name

Oh and the power of a separate storage inverter is added up to the power of the PV inverter and the sum of these can be no more than 6kW officially so anyone with an ME3000SP and more then 3kW of solar inverter is already operating outside of the book 😂

19-10-2021 09:40PM

https://www.boards.ie/discussion/comment/118045471#Comment_118045471

What would unofficially having more than 6kw combined do?

graememk · 19-10-2021 10:03PM

https://www.boards.ie/discussion/comment/118045471#Comment_118045471

"officially" ;)

and there is precedent, here with mp3guy's installl had all the inverters listed on the nc form and no complaints. I'll not be exporting more than 6kw anyways, so no raised eyebrows

slave1 · 19-10-2021 10:55PM

Lol, I'm hoping for 11kWp this time next year across two inverters and a Sofar too on top

DrPhilG · 21-10-2021 03:24PM

What would be the recommended temperature range for a LiFePo4 battery?

Just about to wire in the temp sensor.

garo · 21-10-2021 03:59PM

Here's my suggestion. Feel free to improve on this.

20-30 is optimal.

Leave 10-40 for normal operation.

0-10/40-50 reduce charging to 10A (though this could be higher for larger capacity battery?), discharge as normal.

Outside those ranges don't do anything.

DrPhilG · 21-10-2021 06:54PM

Sitting at 10 currently.

That's from battery cam lol.

In the background there is part of the Kingspan board I just got so I can insulate the batteries.

Ran out of time, just put the sheet at the back to measure, will trim down and then add the other sides and top.

The BMS is a bit snug to the side because I'm still using the same cabling from when they were on the shelf. Now some are a bit short and I wouldn't be bothered changing them to suit the new position.

optip · 22-10-2021 05:32PM

Thanks for sharing @DrPhilG - very nice

peterofthebr · 24-10-2021 07:53PM

can I ask anyone got one of these ?I'm thinking this energy crisis might result in blackouts power fridge, laptop charge phones etc... my idea Is to get solar panels that can work with it too.looking at the lesser nps200 also

https://www.knivesandtools.ie/en/pt/-nitecore-nps400-power-bank-117-000-mah.htm

Nitecore NPS400

MAULBROOK · 24-10-2021 08:14PM

https://www.boards.ie/discussion/comment/118068521#Comment_118068521

€700 thats insane. Money.

unkel · 24-10-2021 08:21PM

€500 per kWh

Most of us are getting our batteries for under €100 per kWh, only sayin'...

peterofthebr · 24-10-2021 08:25PM

https://www.boards.ie/discussion/comment/118068607#Comment_118068607

it's allot their would want to be a power cut for a week to justify that ..:-) the nps200 is around €320..and a solar panel on top of that too

https://www.knivesandtools.ie/en/pt/-nitecore-nps200-power-bank-54600-mah.htm

MAULBROOK · 24-10-2021 08:56PM

I'm at 10.5kw for just over €3500. OK grant money was in that too

peterofthebr · 24-10-2021 09:11PM

https://www.boards.ie/discussion/comment/118068808#Comment_118068808

that a solar panel grand under TAMS2? .I might look into that.. it seems to batteries that the real cost.

unkel · 24-10-2021 10:19PM

https://www.boards.ie/discussion/comment/118068651#Comment_118068651

In fairness that's a nice compact multifunctional unit for not an awful lot of money if it can dig you out of a hole once or twice. You do realise the max AC output is only 150W though? Enough for a few LED lights and your internet router, but you won't be able to power your fridge with that or anything else much...

MAULBROOK · 25-10-2021 08:51AM

https://www.boards.ie/discussion/comment/118068891#Comment_118068891

It was through SEAI grant. You should look into it, good grants available through TAMS2.

Jonathan · 26-10-2021 04:04PM

I got my 5kWh battery installed yesterday (delayed due to supply issues).

I am aware that I can charge it overnight at night rate, and will likely do that in a few weeks, but for moment, I want to see how system performs charging off the panels alone.

One thing that isn't clear to me from the Solis manuals and the support page below, is whether inverter can be set to only discharge battery during certain hours, while matching the house load. i.e. disable discharge during night rate hours.

I obviously don't want the system to discharge at a constant rate during that time until empty.

https://usservice.ginlong.com/support/solutions/articles/36000245193-11-of-20-energy-storage-operating-modes-self-use

Is this possible?

Edit: @jkforde provided answer here. Thanks.

https://myenergi.info/solis-dc-coupled-pylon-eddi-priority-t3887.html#p38575

irishchris · 26-10-2021 04:50PM

https://www.boards.ie/discussion/comment/118075913#Comment_118075913

Just be careful with it and observe for the first day as not sure if what happens mine is the same for everyone. When I set a discharge time it discharges for house load and dumps the rest of the 2.5kw continuously out to the grid at the same time. Have to set 0w export to stop it.

Worth checking yours first though as mine might be an abnormality with the fw version etc

MAULBROOK · 26-10-2021 04:57PM

Leave discharge time at zero and set change limit to 25.

Jonathan · 26-10-2021 05:33PM

https://www.boards.ie/discussion/comment/118076159#Comment_118076159

@irishchris Thanks. I knew someone has mentioned this issue on here, and the Solis support page seems to mention same.

@MAULBROOK Thanks for the photo. Why do are you changing the limit to 25A? Is that a Pylon specific setting? I got a PureStorage II which has a 100A continuous discharge rate.

26-10-2021 05:35PM

Does the battery discharge only when required I assume?

MAULBROOK · 26-10-2021 05:41PM

https://www.boards.ie/discussion/comment/118076346#Comment_118076346

If you leave the discharge at zero the inverter acts as normal

MAULBROOK · 26-10-2021 05:43PM

https://www.boards.ie/discussion/comment/118076340#Comment_118076340

Changing the limit to 25A just to go easy on the battery. A gentle charge if you will.

Jonathan · 26-10-2021 05:57PM

https://www.boards.ie/discussion/comment/118076388#Comment_118076388

Ah, you were talking about charge, while I was talking about discharge, hence the confusion! 🙂 My main priority for moment is to avoid discharge overnight so not to empty the battery running dishwater etc and save charge to offset day rate.

Will try creating discharge time of 08:00 through 23:00 and set a discharge limit of 0A. Will this achieve what I'm after?

MAULBROOK · 26-10-2021 06:07PM

https://www.boards.ie/discussion/comment/118076459#Comment_118076459

No, look at the photo again. Just change the the charge limit to 25A and the charge time to what you need to charge the battery.

Leave discharge time at zero. This will leave the inverter in normal automatic mode.

If you set a discharge time the battery will empty into the grid.

Discharge limit, just leave it at what it was set at.

Jonathan · 26-10-2021 06:14PM

https://www.boards.ie/discussion/comment/118076505#Comment_118076505

Will this achieve what I'm after though? I don't want to charge at night rate (yet). I just want to prevent discharge at night rate. Will your settings achieve this?

Solar PV battery options

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Nitecore NPS400