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Solar PV battery options

DrPhilG

I figured it might be an idea to have a specific thread for this topic. Lots of us have home solar with batteries attached, usually GivEnergy, Pylontech etc usually in 2.4/4.8kWh levels.

Given the cost of batteries and the pending feed in tariff, its debatable whether these batteries will continue to make financial sense, (or if they ever did).

However there is essentially a separate market for the enthusiasts, to have large scale battery storage, 10kWh and beyond.

I thought it would be useful to have a thread for this area specifically, as it is essentially a different topic from the general Solar quotes thread.

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DrPhilG

Some info copied from other threads:

samdeluxjones wrote: »

https://www.bsl-battery.com/powerwalls.html This crowd doing 10kW powerwall for €1770 + €250 shipping.

Anyone use them?

graememk wrote: »

to work out the kwh, its Nominal Voltage[3.2] x Capacity [200] x Number of cells [8] = 5.12kWh

Normally you need 15 or 16 cells for a 48V system that most inverters run on.

What sort of setup do you currently have?

championc wrote: »

If you searched with the word CALB, you cannot have got the link you gave here.

Here is the link and the proper cells

€ 1.389,00 30%OFF | NEW 16PCS CALB 3.2v 200Ah LiFePO4 Rechargeable Battery brand new 200AH 24V 48V 200AH Lithium iron Phosphate Packs Solar Battery
https://a.aliexpress.com/_mtLHTeb

gomamochi1 wrote: »

Is it possible to mix a 5kw pylontech system with these 10kw aliexpress batteries or do I need an independent bms for the ali batteries prior to the hybrid inverter? Thanks

championc wrote: »

Theoritically you could although you must remember that Pylontech use a 15s setup in their batteries, so you would only need 15 AliExpress cells and a 15s BMS

HOWEVER, while the inverters will "talk" directly to the Pylontech BMS, they can't "talk" to the AliExpress cells, But the two sets in parallel may work once you then set the Pylontechs to have a capacity of about 15kW. The power should equally be drawn off both sets and in the same way, charge both sets.

So the important part is that all cells must be of the same battery chemistry and the same number of cells per string.

DrPhilG wrote: »

That was my next question, presumably connecting any unsupported batteries, whether DIY EV cells, or cheap import Chinese cells, wouldn't be supported by the inverter companies and therefore would technically invalidate the warranty?

graememk wrote: »

No different to lead acid, as long as you operate within specifications it's fine.

You'd be far more likely to hurt the batteries than the inverter, if you put incorrect settings in.

DrPhilG

I'm interested in expanding to 20-30kWh in the long run, and then doubling my panels to 12.5kWp.

As I see it there are 3 options currently:

1 - Leaf cells. I can get a friend's 9kWh pack plus full BMS for a bit under €2.5k. I could then add another cars worth of batteries for around the same price, which would add 15kWh and maybe more depending on the SOH of the battery. That equates to a price of around €160/kWh plus a little extra for installation as I would get a pro to finish the hook up.

2 - AliExpress LiFePo4 cells. A know quite a few here have bought these. As I understand it, the pack is 10kWh but around 8kWh usable, and lands here for about €1400. That's about €175/kWh, but do you then need to add more kit, BMS, balancing etc?

3 - BSL-Battery.com. Linked on the other thread, they seem a bit more polished than the AliExpress stuff, and I think they come with inbuilt BMS etc. More expensive, I think someone got a quote of €2k delivered and cleared of customs. But I think that's a usable 10kWh, and no extra kit required.

graememk

All the batteries you mentioned is raw capacity, as you only want to discharge to 80% ish

That's why we say it's only about 8kwh on the CALB cells

Currently my inverter does most of the bms duties, and then I have a passive cell balancer keeping each cell balanced.

Same with the pylontech, it's raw capacity they quote

samdeluxjones

samdeluxjones wrote: »

https://www.bsl-battery.com/powerwalls.html This crowd doing 10kW powerwall for €1770 + €250 shipping.

Orders of 10 or more and they will pay for shipping.

DrPhilG

samdeluxjones wrote: »

Orders of 10 or more and they will pay for shipping.

Boardsie Groupon?

DrPhilG

graememk wrote: »

All the batteries you mentioned is raw capacity, as you only want to discharge to 80% ish

That's why we say it's only about 8kwh on the CALB cells

Currently my inverter does most of the bms duties, and then I have a passive cell balancer keeping each cell balanced.

Same with the pylontech, it's raw capacity they quote

Thanks.

I had thought of doing the same, letting the Solis manage the BMS issues. But then I read this:

"The inbuilt battery management system manages the overall voltage of the 48v battery. It does not manage the modules within the battery which is the most important part of the BMS. If a single cell has resistance issues and overcharges it can cause a fire whereas the overall voltage of the entire battery would not go over its inverter limits"

And it made me think twice.

Then again the LiFePo4 batteries claim that there is no fire risk, so would that mean that a balancer would be the only thing needed?

I'd been looking at relocating batteries to the garage as I wouldn't fancy a potential fire risk in the attic above my bedroom lol.

Are the LiFePo4 really completely safe on that front?

DrPhilG

samdeluxjones wrote: »

Orders of 10 or more and they will pay for shipping.

I'm in Donegal, so I've asked them for a delivery estimate to NI as well as to ROI. God knows how that would work, maybe worse. But might as well get the option.

Definitely could look into a bit of haggling if there were a number of people looking at it.

sebdavis

The BSL battery would be something I would interested in as it would seem more plug & play than buying in from Aliexpress? or am I wrong

DrPhilG

sebdavis wrote: »

The BSL battery would be something I would interested in as it would seem more plug & play than buying in from Aliexpress? or am I wrong

I don't know to be honest, at least 2 if not 3 folk here have the AliExpress batteries.

lightson

I ordered as a test to build first battey which I would use for van work. b4 investing in larger cells for house about 4 weeks ago.

4pcs 3.2V 100Ah LiFePO4 battery pack Lithium iron phospha.

I just chased them up and was told they failed security check and to open a dispute to get refund.

Think they never left china! wondering if anyone had similar problem or what sellers people have used and they have got to Ireland. bit shocked they didn't even get out of china and no idea what failed security check means?

https://www.aliexpress.com/item/1005001651207341.html?spm=a2g0s.9042311.0.0.27424c4dYg7KX5

keen to order some more as I have loads of other bits on way in post from China.

unkel

DrPhilG wrote: »

1 - Leaf cells. I can get a friend's 9kWh pack plus full BMS for a bit under €2.5k

Your "friend" is charging you quite a lot for that, is his paid time to build it for you included?

Leaf packs (24kWh minus degradation) go for about €1500 whole, so say about €110/kWh usable so a bit cheaper than CALB cells (€130/kWh), but the latter are brand new, much safer, not a hassle to get at and super easy to combine into a pack.

unkel

lightson wrote: »

I ordered as a test to build first battey which I would use for van work. b4 investing in larger cells for house about 4 weeks ago.

4pcs 3.2V 100Ah LiFePO4 battery pack Lithium iron phospha.

I just chased them up and was told they failed security check and to open a dispute to get refund.

Major problems getting these out of China for all sorts of reasons. I've had numerous orders cancelled on me, failed to ship, etc. with all sorts of excuses or lack of any communication. You'll get your money back though. Eventually. AliExpress customer service is no help at all though.

Best order from a reputable seller with loads of sales who preferably have a European distribution centre and who guarantee all taxes are pre-paid (otherwise it is likely you will get a nasty surprise of 23% VAT, plus import duty and admin clearing charges)

DrPhilG

unkel wrote: »

Your "friend" is charging you quite a lot for that, is his paid time to build it for you included?

That includes the pack, cabinet, all connections, and a brand new Batrium BMS which costs about €800 by itself.

unkel wrote: »

Leaf packs (24kWh minus degradation) go for about €1500 whole

Do they? Cheapest I've found was £2k sterling.

unkel

Batrium BMS are top notch.

Not sure about the wisdom of sticking an €800 BMS on a €750 battery though. I'd pick a €50 Daly BMS and chances are your pay back time will be half. These are fairly competent yokes. Batrium had its day back when batteries were very expensive and it made sense to invest heavily to protect them.

DrPhilG

unkel wrote: »

Not sure about the wisdom of sticking an €800 BMS on a €750 battery though.

It wouldn't be a €750 battery if I had 30kWh worth. And if the Leaf cells can be a fire risk, I wouldn't cheap out on a BMS.

Also these BSL-battery crowd seem interesting, if indeed the LiFePo4 batteries aren't a fire risk.

unkel

DrPhilG wrote: »

It wouldn't be a €750 battery if I had 30kWh worth.

I thought you said 9kWh?

Obviously a €3000 battery should get different considerations for a BMS than a €750 battery.

lightson

unkel wrote: »

Major problems getting these out of China for all sorts of reasons. I've had numerous orders cancelled on me, failed to ship, etc. with all sorts of excuses or lack of any communication. You'll get your money back though. Eventually. AliExpress customer service is no help at all though.

Best order from a reputable seller with loads of sales who preferably have a European distribution centre and who guarantee all taxes are pre-paid (otherwise it is likely you will get a nasty surprise of 23% VAT, plus import duty and admin clearing charges)

OK thanks

But I guess people are having success

ill try again so

DrPhilG

unkel wrote: »

I thought you said 9kWh?

Tut tut, pay attention young man!

DrPhilG wrote: »

I'm interested in expanding to 20-30kWh in the long run, and then doubling my panels to 12.5kWp.

unkel

DrPhilG wrote: »

Tut tut, pay attention young man!

Eh yeah, you can't just mix and match batteries and add to your existing ones whenever you feel like it.

And if a 9kWh pack based on degraded Leaf batteries costs you €2.5k I guess a 30kWh newish Leaf pack will cost you a good €7k to setup. That will never ever pay for itself man, don't kid yourself again with overly optimistic figures or figures that can even be proven to be technically impossible.

DrPhilG

unkel wrote: »

Eh yeah, you can't just mix and match batteries and add to your existing ones whenever you feel like it.

And if a 9kWh pack based on degraded Leaf batteries costs you €2.5k I guess a 30kWh newish Leaf pack will cost you a good €7k to setup. That will never ever pay for itself man.

Eh yeah, like I said, pay attention...

* I'm not paying €2.5k for a 9kWh battery
(I'm paying, if I went ahead, €2.5k for a 9kWh battery already stripped and built, along with a Batrium BMS. Cut the BMS out of it as you suggested and the pack is €1.7k.)

* I'm not buying a 30kWh Leaf pack
(I would be buying a 24kWh pack of the same chemistry as the original one. You already acknowledged this when you said I'd pay €1500 for a 24kWh so why are you now changing to a 30?)

* I'm not mixing and matching batteries
(see above)

* payback time is not the priority

unkel wrote: »

don't kid yourself again with overly optimistic figures

Now that's just rude. I was hoping that this thread would be a useful resource for those interested in various large battery options, not for you to have a jab at me over past disagreements.

Let's keep on topic?

Plus the Leaf cell battery is one option. I started this thread in order to discuss the others.

sebdavis

Back on topic. So I have 2.6kWh. Now really I would want at least 10kWh along with the 2kWh. My understanding is my 5kW invertor can support more. I have gone back to my supplier but as mentioned it was 2k for another 2kWh and I think 4k for a 4kWh.

If I could get 10kWh for 2k then I would be very happy.
In my limited knowledge I thought I could just buy more batteries and hook them up, but from what people are saying I will need BMS etc.

Has anyone asked if the BSL battery setup can just hook up? If not I wil email and post info

DrPhilG

I've sent an initial enquiry too, I'll report back.

graememk

sebdavis wrote: »

Back on topic. So I have 2.6kWh. Now really I would want at least 10kWh along with the 2kWh. My understanding is my 5kW invertor can support more. I have gone back to my supplier but as mentioned it was 2k for another 2kWh and I think 4k for a 4kWh.

If I could get 10kWh for 2k then I would be very happy.
In my limited knowledge I thought I could just buy more batteries and hook them up, but from what people are saying I will need BMS etc.

Has anyone asked if the BSL battery setup can just hook up? If not I wil email and post info

There doesnt seem to be a standard bms communication protocol. For any of the inverters!

So if the inverter is looking to chat to a bms and dont follow the same protocol, Nothing will happen.

With my setup, the ME3000, in the default profile, it doesnt look for a bms. it just charges and discharges according to its own rules.
the SOC can sometimes get out of whack depending on where it is on the scale and current settings.

mp3guy

graememk wrote: »

There doesnt seem to be a standard bms communication protocol. For any of the inverters!

So if the inverter is looking to chat to a bms and dont follow the same protocol, Nothing will happen.

With my setup, the ME3000, in the default profile, it doesnt look for a bms. it just charges and discharges according to its own rules.
the SOC can sometimes get out of whack depending on where it is on the scale and current settings.

I think this is the key message here, there's no common BMS/Inverter protocol, even if they happen to use CANbus.

DrPhilG

mp3guy wrote: »

I think this is the key message here, there's no common BMS/Inverter protocol, even if they happen to use CANbus.

That's what attracts me to the BSL-battery crowd. They seem to have a lot of support and advice available before you shell out.

sebdavis

DrPhilG wrote: »

That's what attracts me to the BSL-battery crowd. They seem to have a lot of support and advice available before you shell out.

I am a simple man, some might say very simple :-)
Some items I have no issues with trying to do a solo job and 9.5 times out of 10 I am successful but on the PV System if I can pay a few extra quid so it is easier to hook up great

Or even better if I can pay someone to do it for me. But I am not paying 2k for 2kWh. Complete rip off

DrPhilG

sebdavis wrote: »

I am a simple man, some might say very simple :-)
Some items I have no issues with trying to do a solo job and 9.5 times out of 10 I am successful but on the PV System if I can pay a few extra quid so it is easier to hook up great

Or even better if I can pay someone to do it for me. But I am not paying 2k for 2kWh. Complete rip off

Similar position to me then lol.

The standard options around here are nuts. €1k seems the norm for a single 2.4kWh battery from the usual suppliers like the PylonTech that I have currently.

I know it might be a bit cheaper going the Leaf cell route, but it's also a lot more hands on and potentially a fire risk if its not done right.

Same with the cheaper LiFePo4 batteries on AliExpress. Bit cheaper, but still a bit of DIY involved.

The BSL batteries seem to be basically the best of both worlds. The ease of use of Pylontech etc, but with the cheap Chinese pricing.

samdeluxjones

Attachment not found.

The e-mail domain is not same as website domain. sales07@bullsbattery.com

https://www.bullsbattery.com/

but seems to be same company as BLS as both located at the same address.

unkel

DrPhilG wrote: »

Now that's just rude. I was hoping that this thread would be a useful resource for those interested in various large battery options

Some of us have looked into this stuff for years on renewable forums, etc. and have done our own home attached battery installs and our experience might help people who want to do the same to prevent them from making mistakes or from wasting money

I'm not the most diplomatic in expressing myself but if you can't take any criticism of the plans that you have (that are wasteful in my opinion), maybe you should just go ahead and not ask people's opinions...

DrPhilG

unkel wrote: »

Some of us have looked into this stuff for years on renewable forums, etc. and have done our own home attached battery installs and our experience might help people who want to do the same to prevent them from making mistakes or from wasting money

Precisely why I started this thread. Because the likes of yourself, mp3guy, championc and others have a wealth of experience in this field.

unkel wrote: »

I'm not the most diplomatic in expressing myself but if you can't take any criticism of the plans that you have (that are wasteful in my opinion), maybe you should just go ahead and not ask people's opinions...

I have no problem taking criticism and I admit to getting my wires crossed entirely in the previous "annual savings" discussion. Constructive criticism is the most likely thing to help in getting the right solution.

But you didn't just criticise my plans, you misunderstood them, jumped to conclusions, criticised my "friend", then had a dig at me over a previous discussion. You seem to be taking/making this very personal and I'm not sure why.

It was simply uncalled for.

However this thread is not just my plans, there are others here who are interested in the same thing so I don't see the point in derailing the whole thing just because you think I'm an eejit.