Solar PV battery options

Bif

Hi all. I have a Solis 6kw inverter and 5 kw puredrive battery. When charging from the grid on night rate what should the Charge Limit and Discharge Limit be set to? Currently at 050.0A for both. Thanks.

simpsimp

Hi:-

I've been getting loads of quotes and we've narrowed down to three providers...

Just wondering if anyone had any experience with these battery / inverter setups?

• Puredrive Battery 5kWh / Solis Inverter 5kWp
• GiveEnergy Battery 5.2kWh / GiveEnergy Inverter 5kWp
• Alpha Battery 5.7kWh / Alpha Inverter 5kWp

And there's the option for any of those to switch out for a Pylontech 2.4kwh battery for a discount, generally around €1,200

Any thoughts? Thanks!

Jonathan

https://www.boards.ie/discussion/comment/118357942#Comment_118357942

I have my charge limit set to about 10A and charge slowly over the entire night rate period. Easier on the battery and keeps it warm during the winter.

Jonathan

https://www.boards.ie/discussion/comment/118358118#Comment_118358118

I have the Solis/Puredrive. Works well, no issues. Advantage of the Puredrive over the GivEnergy/Plylontechs (not sure about the Alpha) is that it has a 100A discharge which means it can provide up to 5kW of power. It means that you won't need to pull from the grid as often if you have lots of appliances running.

Bif

Thanks Jonathan. Can you tell me where to find the fill and discharge limits e.g. 20% to 80% or do they exist?

simpsimp

https://www.boards.ie/discussion/comment/118358301#Comment_118358301

Thanks Jonathan. I had heard this claim, but good to hear it mentioned by a real world user! I believe this is known as the C-Rating, so here the Puredrive has a C-Rating of 1, while the Pylontech, for example, has a C-Rating of 0.5

I've just noticed that the battery grant may be removed for 2022, so hoping to lock in a grant application this or next week.

It'll be interesting to see if battery prices drop if the battery grant is removed.

Ha Long Bay

Firstly just want to say thanks to all the knowledgeable posters on this forum it's an excellent resource for anyone looking at PV and wish all a Happy Christmas.

I have one battery related question I am thinking to add a second 5KW Puredrive to an upcoming installation. I was quoted €2200 which after negotiation can be provided for 2k. Is this a fair price as it's hard to find wholesale rates?

Jonathan

https://www.boards.ie/discussion/comment/118358713#Comment_118358713

Yeah, that's a fair price for a non-DIY battery. Rule of thumb is €1k/2.5kWh battery, so €2k is spot on.

You'll get comments from others about going down DIY battery route, but it isn't for everyone.

Jonathan

https://www.boards.ie/discussion/comment/118358351#Comment_118358351

As is where do they exist within the Solis settings or what is the Depth of Discharge for the Puredrive battery? If the latter, it is 90%.

Ref: https://varme.nl/wp-content/uploads/2021/02/DC-Installation-Guide-1.pdf

Ha Long Bay

https://www.boards.ie/discussion/comment/118359174#Comment_118359174

Thanks for the reply. I know there are big savings going down the DIY route but not for me. I am just spot checking the quote on the additional 5KW option.

Jonathan

https://www.boards.ie/discussion/comment/118358428#Comment_118358428

Yes, the proper terminology is the C rating.

I really don't think they are going to do away with the battery grant. I think it was just omitted from the press releases. If the intention was to use the grid as a battery, they would have introduced net metering. Self consumption is still the aim of the game, and batteries greatly aid that.

Jonathan

https://www.boards.ie/discussion/comment/118359191#Comment_118359191

Would you mind PM me who that quote is from? Would be possibly interested if I can convince SWMBO.

Ha Long Bay

https://www.boards.ie/discussion/comment/118359215#Comment_118359215

Will do.

Bif

https://www.boards.ie/discussion/comment/118359183#Comment_118359183

Hi Jonathan. Thanks again for that. I was wondering can the DoD be adjusted? Like my car, which recommends keeping the battery at above 20% and below 80% when possible to protect battery life. Is it relevant to the PureDrive?

Jonathan

https://www.boards.ie/discussion/comment/118359653#Comment_118359653

The warrantied DOD from Puredrive is 90%, but you can reduce that if you want. The default config within the Solis is 80%.

The relevant options (OverDischg SOC and ForceCharge SOC) are on the bottom of page 40 of the manual:

https://www.ginlong.com/uploads/file/Solis_Manual_RHI(3-6)K_5G_ENX_V1,5.pdf

To be honest, I wouldn't worry about it.. just leave it at 80% or 90% discharge and let it do its thing. Warrantied for 10,000 cycles anyway, that's 2.7 cycles a day for 10 years.

Bif

https://www.boards.ie/discussion/comment/118359991#Comment_118359991

Sound Jonathan. That’s what I’ll do. Thanks again.

garo

Alright! We are in business. Finally finished connecting everything and the new DIY battery + Seplos BMS is talking to my Growatt inverter and doing what it needs to do. The old battery is disconnected and I am PMing those who were interested in the order they messaged me.

Geeyfds53573

Great stuff congrats Garo was connecting to the inverter more awkward than expected?

I might prepare BMS cables this week but prob won’t see batteries for another month.

anything we should do differently?

Geeyfds53573

I see the Seplos post thanks

https://www.boards.ie/discussion/2058211769/seplos-bms#latest

garo

A couple of lessons for me. The Seplos BMS has four NTC terminals. I wasn't comfortable extending these cables so measure your battery distances and set your BMS cables to terminate at roughly the same point. I gave too much slack to the cables that were connecting to the furthest cells and this has made my install untidy. I may shorten these at some point. Measure twice and cut once.

It pays to think about the orientation your BMS is going to be in in its final state and plan the layout of your 16/25mm2 cables and the angle of your crimps on them. Seplos recommends 2 (or 3 for the 200A BMS) positive power cables and a single for the negative. I crimped two cables each with 16-6 crimps on the BMS end and one 35-8 each for the battery/inverter ends with the wires from both cables going into the same crimp end. Heatshrink wrap was the business.

championc

As for the Seplos unit itself, how have you mounted it, or have you managed to enclose it into something ?

My second set of batteries order price indeed was too good to be true, so I got the full refund from AliExpress, but need to place the order now. I have been somewhat waiting to see if they do a new years sale to save a few more quid on the current pricing

reklamos

https://www.boards.ie/discussion/comment/118380424#Comment_118380424

I would say there should be some deals on Chinese new year that starts in February.

garo

https://www.boards.ie/discussion/comment/118380424#Comment_118380424

No. Not yet. I have a couple of things in mind but right now it’s just sitting in the box it came in - propped up a bit by the wires attached.

I checked last week and the best price at PWOD/Oye I saw was 1440. You can definitely do better by 200.

blobert

Hi Guys,

We've just started work on a new build passive house with a very large south facing roof. We have planning permission to have up to about 30-40kW of solar panels on the roof.

My intention was basically to get planning permission to plaster the whole roof in panels and then when it came time to actually build the house see what made sense economically in terms of tariffs etc. Looks like we won't find out for sure with this for another few weeks but it looks like it won't be great.

Previously it seemed as though battery storage (unlike the panels themselves) did not make financial sense but I've been reading here about the AliExpress DIY route with interest, it seems like you can get 10kW of batteries for a bit over 1k which seems great value.

I have a couple of quick questions on the DIY route for anyone that knows their stuff:

(1) How scalable is it? Most of you seem to have gone for circa 10kW of batteries. Is there any reason I could not do this with 30, 50 or more kW of batteries.

(2) How safe is this? My intention would be to have the batteries and inverter for the solar panels in a "shed" (very well insulated garage type room) separate from the main house by a few metre so the batteries would not be in the main house. That said I have 2 relatively young children and I'd be wary of anything that would cause serious harm if someone touched the wrong wire (though I'd have some sort of barrier to prevent access to the batteries). I see a bit of talk of "the whole thing could go on fire" but I'm assuming that's pretty unlikely

(3) The new house will have 3 phase power (partially to facilitate greater export of power) but mainly as we're building a very large house which despite being passive standard will still use a lot of power and be entirely (inc electric cars) run on electricity. Is there any issue with using the DIY battery rigs here with 3 phase power?

(4) I'm not up to date with my battery knowledge. Is there anything coming down the tracks that might drop the price of the standard Powerwall type products significantly in the near future? I'd ideally prefer not to have hundreds of batteries linked together in my shed vs some off the shelf product but at the moment it seems only the former option makes economic sense.

Sorry for the long post and thanks!

slave1

1.Scalable in terms of 16 AFAIK, so 16/32/48 etc, your limitation is likely going to be output (determined by inverter)

2.AE batteries mentioned on this thread safe for storage in house

4.Linking is the most economic path at present

PS forget about export, do your best to plan/scale to self consume/store

Good luck with build, sounds very interesting

garo

1. No limit on scalability. 16 200Ah LifePO4 batteries get you 10,240Wh nominal. You can scale to 32, 48, 64 or more. The battery packs will all operate in parallel so will be at 51.2V nominal.
2. LifePO4 is very safe. No risk of fire. Different chemistry to Li-ion that is used in Teslas and laptops and cell phones. As far as exposed wires are concerned, use the same basic precautions you would use with any electricity wires. Get yourself a case or cabinet to keep the batteries in and use insulated shrinkwrap to minimize any exposed surfaces.
3. No issue with 3 phase but you will need a three phase storage or hybrid inverter. You also need to decide whether you will get a hybrid inverter that connects to both the PV array and batteries or a non-hybrid for the PV array and a separate storage inverter for the batteries. Latter is more flexible, about the same combined cost for non-hybrid+solar inverters as a hybrid inverter but takes up more space. 3-phase inverters are also more expensive that single phase equivalents (but can handle larger arrays). I am not even sure if 3-phase hybrid inverters are easy to procure in Ireland so you may have to go separate PV and storage inverters.
4. Supply is tight right now as EV production ramps up. I don't think battery systems are getting cheaper in the next year or two. A 50kWh storage system (and you most likely won't need that) will be 80 cells not hundreds. Yes it's a large install but you can separate them into 16 cell modules, find or build decent storage cases for them. It's doable.

garo

A 10kWh battery is frickin' awesome. After over 2 years of a 2.4kWh Pylontech, it's amazing to have everything covered by the battery all day and still be at 50% at 8pm and later in December. Will recommend. ++

Feidhlim

https://www.boards.ie/discussion/comment/118359220#Comment_118359220

Likewise if it's not too much trouble! Thank you!!

graememk

For home built batteries a few YouTube channels to look at :

Off grid garage, lithiumsolar, digital mermaid(that one's for a boat), will prowse, solar garage.

With three phase it makes it a bit more complicated (expensive) getting the right inverters etc but not impossible.

Most of us have bought 200ah cells. But there is 300+ on the market.

Oh give yourself plenty of space in your plant room. If your going of the shelf or DIY, all of them need space.