Solar PV battery options

Jonathan

https://www.boards.ie/discussion/comment/119739013#Comment_119739013

Its a private FB group so can't link directly, but join and you'll see it as one of the recent posts:

https://www.facebook.com/groups/288045168816481

the_amazing_raisin

https://www.boards.ie/discussion/comment/119738886#Comment_119738886

Yeah blending batteries is one of those areas where you've definitely graduated from enthusiasm to industrial scale

I think for Quattros running in parallel you need them connected to the same DC bus

For what you want I think you could have a Quattro with your generator and grid on the two AC outputs and one set of batteries on the DC bus

Then you can have another inverter AC coupled to the output of the Quattro, with the second set of batteries on it's own DC bus

You can split your solar panels across the two DC buses, or keep them on one of you have enough power available in your inverter

There are however a lot of design considerations, the page below might help

https://www.victronenergy.com/live/ac_coupling%3Astart

Also, quick disclaimer, I'm not a solar expert. Get an engineer to design the system properly for you

poker--addict

Trying to educate myself on batteries. Looking at 10kw power wall option. $2400 delivered to port. Need to get an idea of extra charges I need to factor.

But first, what does the Max Discharge current dictate? Safety wise is lifePO4 far safer and should I avoid lithium which I understand this Rosen to be?

unkel

LiFePo4 is lithium. "Li" is the symbol in the periodic table for lithium. The names of those battery packs in your table start with "LFP" which is a more popular spelling of Lithium iron (iron = Fe in the period table) Phosphate. The exact same thing as LiFePO4 😃

Before you choose your battery, you need to choose your inverter as not all inverters can work with all batteries. Also all those ready made packs are poor value for money. Some of them are poorly made or use poor quality cells. Even the packs with very good reputations. I would strongly advise you to consider making your own pack. It's not hard. Several forum regulars have done it even though they had zero experience with any of this. There are several threads about it here and people are very helpful getting you going and helping you out if you got stuck. It's also a super fun experience and you'll be proud of your achievement.

Ubbquittious

https://www.boards.ie/discussion/comment/119739708#Comment_119739708

Is that Chinese stuff? There is a fierce amount of sh1te out there when it comes to normal non grid-tie inverters and also solar charge controllers. You have to be very careful with what you buy

the_amazing_raisin

https://www.boards.ie/discussion/comment/119739708#Comment_119739708

Max discharge current is the amount of current you can draw from the battery at one time. Multiply by battery voltage to get the maximum power supplied from the battery

So taking the 100Ah example above, it has a max discharge current of 100A, times 48V gives 4.8kW. So if you try to power a 9kW electric shower off this you won't be able to, the battery will shut down to protect itself

It's also worth noting the recommended discharge current is usually half that amount, and there's often a limit to how long the BMS will allow the max discharge current

You'll need to factor this is when determining your power needs. Ideally you want to be able to draw enough power from your battery to cover any instantaneous demand you're likely to have

One method is to add up the electric loads in your house, but once you do this you'll probably comes up with a 40kWh battery

A more realistic method is to look at what consumers you can manage to reduce the instantaneous demand. For example, not running the washing machine and dishwasher at the same time you're cooking dinner

When your inverter can't cover the demand from solar and battery, it'll draw from the grid. So it's an exercise of matching the battery, inverter and loads

poker--addict

Unkel, tempting, but time is precious at the moment with work and fam. That said I spent bloody days picking the quote for panels - but strong argument that I should have been happy to pay a bit more and not lose all that time, hence leaning towards paying a bit more and having a pack I can just hook up - no balancing, no figuring out a BMS, no checking amps or whatever in individual batteries. I’d need to buy all those bits and pieces too for testing.

I don’t doubt it would be cool to do and feel good at the end. But how many man hours (can we say man hours anymore?) realistically will it take assuming an average number of mistakes or issues?

championc

Testing is somewhat pointless. It will get you pretty much nowhere. I do feel that you need to charge the cells, let them sit for 24 hrs and charge again if below the max.

Only then will you get the true capacity (whatever that might be)

unkel

https://www.boards.ie/discussion/comment/119738893#Comment_119738893

I looked it up, it's basically a cheap Chinese rectifier that needs to be programmed by the manufacturer for a certain DC output voltage but has 3kW power. Saw them on AliExpress for about €66 + €43 shipping, so bloody cheap. R48-3000e3 is the model, can be several different brands

Just bought one. Might come in handy. That said, with our 9 hour period of night rate, most inverters are fine to charge up batteries up to 20kWh from empty to full every night, which only takes about 50-60A

ELM327

https://www.boards.ie/discussion/comment/119740507#Comment_119740507

+1

If I could give myself advice 6 months ago it's that battery packs are the easiest to add on and DIY, build your own bank!

Bif

Hi. I’m about to wire in a second Puredrive 5kwh battery onto my (Solis 6kwh inverter) PV system. I was wondering if anybody else has a similiar setup and could send me a photo of how it is wired? Thanks.

Midlakelands

Here's my putedrive setip from a from a previous post

https://www.boards.ie/discussion/2058165926/solar-pv-battery-options/p69#Comment_118943927

Jonathan

https://www.boards.ie/discussion/comment/119744349#Comment_119744349

While @Midlakelands wiring will work, it doesn't distribute the load evenly across the two batteries. The correct way to wire them is so that the current must flow evenly through both batteries. I'll do up a diagram later.

Bif

Thanks for that @Midlakelands!

Bif

https://www.boards.ie/discussion/comment/119744515#Comment_119744515

Thanks Jonathan.

Midlakelands

https://www.boards.ie/discussion/comment/119744515#Comment_119744515

Yeah I've wondered why they recommend this setup in their documentation. might be worth sending their support a query

con747

https://www.boards.ie/discussion/comment/119744515#Comment_119744515

When I was joining my second battery you had me scratching my head when you told me to do that because the second battery was an end of series and only had 1 + and 1 - connection on it!

Jonathan

https://www.boards.ie/discussion/comment/119744723#Comment_119744723

Diagram below. Basically, each battery should have three battery connections. Battery 1 has two + connections and one - connection. Battery 2 has the inverse; one + connection and two - connections.

                     ┌──────────────────────────┐
                     │                          │
                     │                          │
                     │      Solis Hybrid        │
                     │                          │
                     │                          │
                     └────┬───┬─┬───┬─────┬───┬─┘
                          │ + │ │ - │     │CAN│
                          └─┬─┘ └─┬─┘     └─┬─┘
                            │     │         │
                            │     │         │
                            │     │         │
 ┌──────────────────────────┘     └─────────┼────────────────────────────────┐
 │                                          │                                │
 │                                          └──────────┐                     │
 │                                                     │                     │
 │     ┌───────────────────────────────────────────────┼─────────┐           │
 │     │                         Puredrive Battery 1   │         │           │
 │     │                                               │         │           │
 │     │                                             ┌─┴──┐      │           │
 │     │                                             │ UP │      │           │
 │     │                                             └────┘      │           │
 │     │    ┌───┐ ┌───┐       ┌───┐ ┌───┐                        │           │
 └─────┼────┤ + │ │ + │       │ - │ │ - │            ┌────┐      │           │
       │    └───┘ └─┬─┘       └─┬─┘ └───┘            │ DN │      │           │
       │            │           │                    └─┬──┘      │           │
       │            │           │                      │         │           │
       │            │           │                      │         │           │
       └────────────┼───────────┼────────-─────────────┼─────────┘           │
                    │           │                      │                     │
              ┌─────┘           │                      │                     │
              │                 │                      │                     │
       ┌──────┼─────────────────┼───────────-──────────┼─────────┐           │
       │      │                 │ Puredrive Battery 2  │         │           │
       │      │                 │                      │         │           │
       │      │                 │                    ┌─┴──┐      │           │
       │      │                 │                    │ UP │      │           │
       │      │                 │                    └────┘      │           │
       │    ┌─┴─┐ ┌───┐       ┌─┴─┐ ┌───┐                        │           │
       │    │ + │ │ + │       │ - │ │ - │            ┌────┐      │           │
       │    └───┘ └───┘       └───┘ └─┬─┘            │ DN │      │           │
       │                              │              └────┘      │           │
       │                              │            EOL RESISTOR  │           │
       │                              │              IN DN       │           │
       └──────────────────────────────┼──────-───────────────────┘           │
                                      │                                      │
                                      │                                      │
                                      └─────────-────────────────────────────┘

https://www.boards.ie/discussion/comment/119744764#Comment_119744764

Yeah, I'm not sure either. It is a bit odd, but every other battery wiring diagram is wired this way.

https://www.boards.ie/discussion/comment/119745353#Comment_119745353

Yeah, the second PD you bought seems to have been a first generation one with which required a DC combiner box for multiple working.

Bif

Thanks for that @Jonathan. Up and running now!

j98c

Hi all,

Just received a quote for a 5.6kWp system with 2x2.4kW (4.8kW) batteries.

This is the first quote I've received that has stated more than 1 battery so I'm wondering are there any pros/cons of having a dual battery instead of a single battery?

unkel

https://www.boards.ie/discussion/comment/119759596#Comment_119759596

The second battery will NEVER pay for itself. The first one will probably even struggle over 15-20 years, even if the peak rate electricity will go up way higher than it is today.

Evd-Burner

Can anybody help in regard to where to source the Sofar ME 3000SP?

Been looking for a few months with every few days and wasn't able to find one, now I finally have the time & funds to go DIY and it seems the ME 3000SP can't be gotten anywhere.

Was sick I missed out on the one Unkel sold :P

Evd-Burner

I got a response on another thread for 2 possible sources.

Has anybody heard of or used the Solis RAI-3.0KW 48ES 5G AC Coupled Inverter?

unkel

https://www.boards.ie/discussion/comment/119759810#Comment_119759810

I'm going to sell my current one. It's working perfectly fine, but the CAN port doesn't seem to work and possibly the comms RS485 port is not working either. So if you are going to use it with a home made battery (any lead acid or any lithium chemistry) and not looking to control the ME3000SP from the BMS or do home automation with it, it's a fine choice. It will be cheap, very cheap.

I do have to find a hybrid inverter first though...

Mr Q

https://www.boards.ie/discussion/comment/119760322#Comment_119760322

I would be interested in the ME3000SP, my BMS doesn't need to communicate with the inverter.

Will you be putting it up here or Adverts?

unkel

I'll probably mention it here in the forum, but it will be on adverts for sure, if you put up an alert for "ME3000SP" you will get notification very soon after the ad is up

Galego

https://www.boards.ie/discussion/comment/119759773#Comment_119759773

Curious to understand but the second one never but the first one might......not challenging you there only would like to know.

unkel

To get a battery, you will need either a hybrid inverter or a separate dedicated battery inverter. These are expensive. The batteries themselves are expensive even those small 2.4kWh ones are €1000 each. Even without a FIT, they would struggle to pay for themselves. And now we have a FIT that is around 14c / kWh, batteries simply don't make financial sense any more.

If you could cycle your battery once a day (this is optimistic) and use it for the peak tariff that's about 2.2 kWh usable * 2 per day * 365 days - 20% losses = 640kWh and you would save €0.30 per kWh vs €0.14 FIT, you'd make €100 per year from it. From a system, incl. install cost of at the very least well north of €2500 (with one tiny battery)

But who knows, we could be hitting €1 per kWh electricity at peak times, then it would make more sense.

jspuds

Myenergi have just announced a new Inverter and Battery option

https://myenergi.com/libbi

Evd-Burner

https://www.boards.ie/discussion/comment/119760322#Comment_119760322

Thanks Unkel,

I have no plans for automation etc, I intend on using a Seplos BMS for a DIY LifePO4 battery. If the ME3000SP you have is already working in that configuration then sounds good to me.

Battery wise it would be December at the earliest before I had the cells. Quote from Jenny Wu is for 16 cells EVE LF280K shipped from EU to Ireland, the cost is 132*16+136=2248USD, add Alibaba trade assurance fee 56USD, the total is 2304USD.

Going to start sourcing the Seplos now too, anybody with a source feel free to jump in :)

Evd-Burner

https://www.boards.ie/discussion/comment/119761358#Comment_119761358

Hmmm, interesting. Don't see any prices though, will most likely be prohibitive.

Would be nice to have this integrate to my current Zappi install and potential future Eddi install when I'm able to increase solar setup in the future.

THE ALM

https://www.boards.ie/discussion/comment/119761358#Comment_119761358

Viewed it at the NEC alright. Will be interesting to see the price point. Seems to be a re-badged kstar product.

Price and integration with existing products will be key.

Galego

https://www.boards.ie/discussion/comment/119760568#Comment_119760568

Did you multiple by 2 your usable Kwp?

I know it is very optimist to do two cycles every day for a year but these are the numbers I get. Am I missing something here or getting something wrong? My payback times dont seem too bad.

unkel

Do you really pay 38c / kWh? That is very high. I pay 28c and that is high, but the offset is that I pay less than 8c for night rate

And yeah, not a hope you will average two cycles per day. And why do you have €1000 for initial cost? It's more like €2500. The battery is €1000 (if you're lucky), a battery inverter is €1000 and a hybrid inverter is nearly €1000 more than a normal inverter and then there is the install cost, at least €500. So even with your rates, that would be 40 years for one cycle per day and 20 years for two cycles a day (the inverter is not gonna last 20 years, so will have to be replaced in the meantime, adding to your pay back period)

Either DIY if you can buy parts at really good prices, or don't do it for financial reasons anyway as it makes no financial sense.

Galego

https://www.boards.ie/discussion/comment/119762063#Comment_119762063

Initial cost considers only the cost of the battery itself and at 500eur per 1kwh. It assumes the person already has hybrid inverter. Anyway, that is my case at the moment. Hybrid solis inverter but no battery. Also, 100% agree. Zero hope of getting two cycles 365 days.

I am with SSEA. Stuck with them till march and yes @38c in a 24hr meter and going by what they call their standard rate is even a decent deal!!!

unkel

That's a disgraceful rate. You could break your contract for just €50. Could save you a lot more than that. But yeah your hybrid inverter is already installed, so you already have sunk cost (and a substantial loss if you don't go battery). That skews your sums though, they apply to you, but do NOT apply to someone who hasn't yet installed any PV / battery

Another option is to cut your losses and sell your hybrid inverter, buy a standard inverter and make some of that sunk cost back. Of course only if you have decided not to go battery in the near future!

graememk

https://www.boards.ie/discussion/comment/119762206#Comment_119762206

Just to pump the brakes on that switch...

And move where?

This is the ev tariff that we're on now...

And there's barely anything below 40c now.

unkel

Jesus Christ. And I switched only so a few weeks ago, paying under 8c now night rate. Obviously the higher the day rate gets, the more a battery makes sense. Maybe we're only months or a year, two tops away from €1 / kWh rates.

spaced

https://www.boards.ie/discussion/comment/119762343#Comment_119762343

You would be lucky to find anything under 35c for domestic at the moment.

It's 50c+ for business, and only 4 companies are accepting new business customers. the last price i saw was 56c for the day wholesale rate, energy costs have trippled but this hasn't been passed fully to the domestic market yet.

unkel

Looks like I got lucky then changing a few weeks ago and fixed rates for the year. And that I more than trebled my battery size in the last few months to well over 30kWh. And installed a ton of extra solar PV since early last year

HotSwap

Who is your provider? I understood from a conversation that I had with someone from the CRU that there was no such thing as a fixed domestic contract. Are you domestic or commercial or agricultural?

HotSwap

I don’t see anything like hybrids costing 1000 more than non hybrids.if you are on the fence about a battery and want to see some data from your install before finally making a decision on a battery I think it would be shortsighted to not get one. But that’s just my opinion; you can of course benefit from a lower cap ex cost if you are sure you never want a battery (or are happy to go with an AC battery later on).

manufacturer 1: 5kW non hybrid 700 euro. Hybrid version 5kW from same manufacturer 1100 euro.

manufacturer 2: 5kW non hybrid 500 euro hybrid version 5kW from same manufacturer 1050 euro.

These prices are ex vat and not exact prices; rounded up and down slightly.

can you give some examples of your 1000 euro difference?

unkel

Never mind that shower of incompetents in the CRU. They haven't a clue. I am, like many many others in this forum, on the Energia EV plan. So yes, just domestic. This means fixed rates for a full year. Not fixed discounts.

yankinlk

https://www.boards.ie/discussion/comment/119762744#Comment_119762744

Hoping you get that fixed rate.... but there have been quite a few posts of energia customers discovering a bump in there most recent rates on bill

HotSwap

https://www.boards.ie/discussion/comment/119762744#Comment_119762744

This plan is currently 47.77 cent day rate and 13.75 cent night rate. I’m familiar with Energia bills; do you have a “gas charge” on there?

So your saying that if I sign up to this plan today; Energia cannot increase my unit rate for 12 months? It’s 47.7/13.75 fixed?

graememk

https://www.boards.ie/discussion/comment/119762657#Comment_119762657

Domestic.

Energia's ev tariff has been fixed for over a year and a half.

Currently on my second contract with them. (Renewed at the end of July)And was going at least 6 months before I first signed up in 21.

Not sure if it's still fixed, but it was in Sept.

https://www.boards.ie/discussion/comment/119762766#Comment_119762766

As for the price bump. Apparently that's a billing error...

unkel

Yeah I was one of the first to sign up for the EV plan when it was launched early last year. I enjoyed a full year of 4.78c / kWh incl. VAT. Incredible rate even back then.

THE ALM

Like unkel and a few others here I manged to get the Energia EV plan at .2744 day and .079 night fixed unit rate 12 months. There are caps on the units used for the bi-monthly cycle but don't envisage us ever getting near them.

Those prices did start jumping come mid August, I think, so nothing is coming close to them.

There was a billing error on the last bill where they charged the wrong unit rate which actually resulted in our bill going down.

THE ALM

Back to battery options.

I wonder will the Libbi battery controller unit be compatible with other inverters as it is a stand-alone unit which communicates with the inverter? At the show yesterday information was lacking but it could be a way to integrate third party products.

championc

Do you mean buy the inverter but not the storage ? If so, then it depends on compatibility of the inverter to talk with other battery types.

The inverter is a re-badged KStar. Here's a useful link, with a downloadable pdf link on the page

https://suministrosdelsol.com/en/hybrid-inverter/1913-kstar-blue-s-5000d-hybrid-inverter.html