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

graememk · 15-11-2022 8:50am

https://www.boards.ie/discussion/comment/119875141#Comment_119875141

The smart ones, can be set to only balance on the top end. And can be left on all the time. Balancing both ends could end up throwing off the balance.

As you are going for a 16s2p, you still only need 1, as too cells in parallel act as 400amp cells.

unkel · 15-11-2022 10:09am

These are my settings for the NEEY active balancer. I charge fully at night every night so it is balancing at the top. Might re-visit this next spring.

Geeyfds53573 · 15-11-2022 5:59pm

https://www.boards.ie/discussion/comment/119875981#Comment_119875981

Thanks @graememk - wasn’t thinking that makes sense - @unkel thanks most helpful .

poker--addict · 18-11-2022 8:26pm

BMS Q. There are lots of options on aliexpress.

48V 16s 200A LCD USB

48V 16s 100A LCD USB

48V 16S 150A LFP

24V 8s 100A

what does it all mean? What do I need? Inverter is 6KW. 16 cells on the way.

championc · 18-11-2022 9:08pm

https://www.boards.ie/discussion/comment/119891423#Comment_119891423

So you need 48v model (although 16 x 3.2v = 51.2v

16s means 16 cells linked together in series

xxxA is the max power that the batteries can deliver (Amps x Volts = Watts so 100A x 50v = 5kW)

poker--addict · 18-11-2022 10:15pm

Thanks champion. I believe OP had 200a batteries? But 150a BMS, are we suggesting for 10kw made up of 200A it really be 200a BMS?

looks to be about 60e difference between 150a version and 200.

LCD screen needed ya?

championc · 18-11-2022 11:01pm

https://www.boards.ie/discussion/comment/119891812#Comment_119891812

Don't confuse your kW's with your kWh's

The batteries contain 10kWh. A 5kW inverter could discharge the full 10kWh of batteries in 2hrs.

And a 5kW inverter may not necessarily be able to discharge at a rate of 5kW, and it would depend on inverter specs.

So realistically, most could get away with 100Ah BMS giving you the possibility to discharge at 5kW rate.

unkel · 19-11-2022 1:18am

Took mine down this evening from my outdoor steel cabinet and installed it in my shed / workspace. Figured with one full cycle a day and 80% round trip efficiency, I'm wasting about 4kWh of heat going into the garden. Might as well use that to provide pretty much all heating I need even on a cold day for my well insulated shed

20kWh in 16S2P CALB 200Ah cells, soon going 16S3P for 30kWh

On top a NEEY 4A active smart balancer with bluetooth and phone app. About €100 delivered incl. VAT from AliExpress. Highly recommended.

Mr Q · 24-11-2022 9:51am

The NEEY balancer that @unkel mentions above is currently under 88 euro delivered from Aliexpress.

Not sure how cheap it has been before but don't recall seeing it that low.

unkel · 24-11-2022 10:43am

Total bargain for what it can do. FWIW I paid €114 delivered incl. VAT about 2 months ago.

Geeyfds53573 · 24-11-2022 7:37pm

https://www.boards.ie/discussion/comment/119914312#Comment_119914312

Hankzor is the reliable store for the Neey I believe - I see a dodgy store selling it at that price be careful

unkel · 24-11-2022 8:12pm

Yes, a lot of the time if you see a very good price it's from a store like "store00121348" with lots of orders but only 1 or 2 (bogus) feedbacks. Only go with the known good stores. I've been bitten many times, greedily buying the "bargain" that turned out to be bogus. You will get a full refund from AliExpress no probs, but it's still annoying and from order to getting a refund, order again and get delivery, it will be 5 months later.

poker--addict · 25-11-2022 7:40am

What size box will fit 10kw of batteries? Have seen the plastic box one boardie is using and it looks tidy, but a tad lacking in height.

ELM327 · 25-11-2022 9:57am

https://www.boards.ie/discussion/comment/119917424#Comment_119917424

Yes me too.

At least the refund was automated!

unkel · 25-11-2022 10:54am

NEEY working beautifully

But I'm tempted to buy the JK BMS with built in active 2A balancer that your man from the Offgrid Garage recommends. Good Black Friday deal on them today

unkel · 25-11-2022 11:00am

Mate just bought 10kWh of CALBs from PWOD paying €1368 at checkout, even if paid in EUR. That's a very good price if anyone is tempted. LOL those pre made inferior batteries cost 4 times as much!

Mr Q · 25-11-2022 11:00am

https://www.boards.ie/discussion/comment/119917293#Comment_119917293

It was Hankzor for that price.

But you are right about the amount of dodgy stores on Aliexpress, also made that mistake before.

unkel · 25-11-2022 11:08am

Just bought the JK BMS (200A) with active 2A balancing and CAN for just €158, that's a bloody bargain. From Hankzor.

Scoopsire · 25-11-2022 12:21pm

Whats best to use Revolut or Credit Card to purchase on aliexpress, or does Card charge back even come into this if there is a dispute?

championc · 25-11-2022 12:25pm

If buying batteries, ONLY buy from PWOD.

For purchases in general, all pricing is in US$. So there is a gain (saving) by having Revolut convert from US$ to EU€

shazbot1 · 25-11-2022 6:50pm

https://www.boards.ie/discussion/comment/119855698#Comment_119855698

Unkel, great detail and comments and you seem to be the one to ask.

2 questions, how difficult to connect these LifePo4 batteries to Solis Hybrid Inverter? using a Seplos BMS or similar.

Also do they always have to be 16S ie 48v or could you use 8S ie 24v, 280ah ones to give you about a 7.5 KWH battery?. Will Solis charge at 24v. Thanks for your time..

Geeyfds53573 · 25-11-2022 7:19pm

Not too difficult read the Seplos thread - need 16 batteries voltage needs to be 48 to 60 range or something close to that.

ELM327 · 28-11-2022 10:13am

https://www.boards.ie/discussion/comment/119921147#Comment_119921147

In short, yes, follow the wiring diagram and use the seplos BMS.

These are basic cells, you can wire them up however you want once you have the correct BMS. It's unlikely that you have a 24v inverter though.

DC999 · 28-11-2022 6:33pm

Pure ballpark as I’ve only scanned this thread. What’s a rough cost in euro for a 20kWh DIY battery? To the closet grand is all I need for now. So to get everything connected so it can ‘talk’ to my current Huawei inverter, and I don’t even know what kit is needed. Physical kit: Cells, balancers, cables, busbars, housing (which might just be timber or metal), BMS…. Would go in the attic which is cold and roasting at times so needs a heating matt & some insulation (winter) + airflow for summer?? Then vat, delivery… Plus sparks costs: Roughly how long do you need a sparks for? And for what parts are they needed?

I’ve a Huawei inverter which is limited to only 2 battery brands it works with and they cost the earth. I knew that when I bought it but was only inverter installer could get at the time. So I won’t be getting a battery connected to that.

Up to this I was firmly against DIY it as ‘above my pay grade’. But I’d like to be able to get one for my folks (they don’t & won't have solar, in their late 70s). So they could run from a cheap night rate forever more. 20kWh would mean my folks could use for electric heating too and not worry about ‘rationing’. Then one for me. Rest of family would want one too of course 😊

championc · 28-11-2022 9:31pm

Straight away, the Huawei inverter is seen as a proprietary unit, and incompatible with most 3rd party batteries, so you need to do your homework on a BMS to be quite sure that they talk the same language. I certainly don't think that the Seplos is compatible.

Of course, you could go with a Seplos and simply only hook the DC cables to the Huawei Inverter, so long as you can define the battery by voltage settings

Mr Q · 29-11-2022 2:42pm

https://www.boards.ie/discussion/comment/119932094#Comment_119932094

Huawei inverters use a battery that is in the region of 400 volts. You won't be able to connect anything DIY to that.

shazbot1 · 01-12-2022 9:24am

Do you leave the NEEY active balancer on all the time? or just switch on when the mv difference is high? if so how often do you need to Active balance the LifrPo4 batteries? thanks