Solar PV battery options

sebdavis

DrPhilG wrote: »

Further update from the AliExpress seller.

2 of the 16 pack was coming to €2,670 after discounts. I asked if there was any further discount available so he sent me a link for a 32 pack, for €2,691!

It pays to haggle...

Those who have purchased from these guys, a few more questions.

1 - do they deliver to your door? I know that they bring them into Poland or somewhere, clear customs and then onwards. But does that second dispatch bring it to your home address or just to the nearest port like the BSL crew?

2 - how secure is it, sending this amount of money across the world? First time buying on AliExpress so a little wary of being ripped off. Would credit card transaction still offer protection?

Who are you dealing with on Aliexpress?

DrPhilG

sebdavis wrote: »

Who are you dealing with on Aliexpress?

Oye store. I believe that's the same one that championc etc have dealt with?

sebdavis

DrPhilG wrote: »

Oye store. I believe that's the same one that championc etc have dealt with?

After you guy the 32 pack, what else do you need to buy? The BMS?

DrPhilG

sebdavis wrote: »

After you guy the 32 pack, what else do you need to buy? The BMS?

Well I'm buying 2 x 16s, since they're on offer and therefore cheaper than the 32.

As for what else is needed, see my previous list of questions as that's what I'm just clarifying before proceeding.

DrPhilG

PS where have you guys stored your batteries?

Unkel has them in an outbuilding/garage I think in a steel/brick enclosure, what about the rest of you? Are these any more or less of a risk than the PylonTech currently in my attic?

If I put them in the attic I won't need to mess with inverter location. If I have to shift them to the garage now then I'll have to move the inverter and reverse the setup, i.e. connect the house panels to the garage rather than the garage panels to the house.

If/when I double my panels then I probably will move the whole lot out but I'm not planning that in the immediate future.

graememk

DrPhilG wrote: »

Getting close to pulling the trigger on 2 packs. So even more questions...

1 - can the 2 packs join together to make one larger pack? I think this is answered here, but this leads me on to question 2.

So you could have 2 strings of 16 and parallel them at your breaker, but that would need 2 bms's

Or you could parallel every 2 cells together, you might need extra busbars.
but you would only have to put a balance lead on each pair of batteries.

You need 2 bus bars for every pair, so thats 32. and then another 15 to join all the pairs. 47 in total.

Remove 1 busbar for every split in the pack where you use wire, ie if you make 2 rows of 16 or 4 rows of 8.

Each cell comes with 1 bus bar. so you'll normally get 32

Draw it out and see.

3 - what else do I need to have in my shopping list to make this all complete. Busbars etc come with the cells. I need a BMS (no problem paying a little extra for the Heyo if it's worth it), and cables to connect the cells to the inverter. Anything else? Do I need a balancer if I have the BMS?

You need to get a beefy BMS able to handle at least 100amp charge.

Re the BMS, that will do the balancing, The extra features of the bms, ie low voltage cut off etc is a fail safe, it should never actually have to do that.

What you need to plan, or get
How they are stored/mounted.
Need a Fuse/DC MCB, Enclosure for that MCB you'll be looking for a 100amp one. Needs to be a DC one, Stuffing glands for said box.

Wire, Ideally black and red, and you would need 16mm2 too as you have a 5kw inverter.
Heatshrink, crimp Terminals to go on the wire and onto the battery.

DrPhilG wrote: »

Oye store. I believe that's the same one that championc etc have dealt with?

yep, thats where he got his, I have dealt with PWOD but they have the same photos in their listings. Comes via UPS.

DrPhilG wrote: »

PS where have you guys stored your batteries?

On Shelves built for them in my garage ( well a room off the garage, where a freezer used to be kept back in the day)
I have 2 rows of 8, currently surrounded in insulation to keep them warmer.

DrPhilG

graememk wrote: »

Or you could parallel every 2 cells together, you might need extra busbars.
but you would only have to put a balance lead on each pair of batteries.

This sounds like a decent solution. Copper busbars from the same seller are €18 for a set of 4 but I could try and haggle them into the deal.

graememk wrote: »

You need to get a beefy BMS able to handle at least 100amp charge.

That was my next query, is there a particular model in the Heyo or Daly options that will cope with the load for a doubled up battery?

graememk wrote: »

What you need to plan, or get
How they are stored/mounted.

My plan was to put them on a shelving rack in the attic. Depends on the layout though, I'm guessing they need to be end to end due to the busbar connections. Actually edit, I see you have 2 rows of 8 so I could do 2 rows of 16.

Any pics of your setup?

Also was wondering about the safety of having them in the attic but since they're probably no more of a hazard than the PylonTech I suppose it's fine. When I double up on panels and inverters I will most probably shift the lot to the garage.

graememk wrote: »

Wire, Ideally black and red, and you would need 16mm2 too as you have a 5kw inverter.
Heatshrink, crimp Terminals to go on the wire and onto the battery.

16mm2 a minimum? Or is there no harm in going higher spec?

I'll likely round up all that stuff locally. Just buy the BMS, cells and busbars from China.

graememk

DrPhilG wrote: »

That was my next query, is there a particular model in the Heyo or Daly options that will cope with the load for a doubled up battery?

As long as the current rating on it is higher than what your looking to draw from the battery.

Also was wondering about the safety of having them in the attic but since they're probably no more of a hazard than the PylonTech I suppose it's fine. When I double up on panels and inverters I will most probably shift the lot to the garage.

Pylontech are the same chemistry, but they are in a metal box,

16mm2 a minimum? Or is there no harm in going higher spec?

Just looked up the manual for the solis.
the max you can pull from a battery is 62.5amps (3kw) - Or put into the battery.

so a 63 amp mcb and 10mm2 wire is fine.

also the next step up from 16 is 25mm2 and its hard to work with.

sebdavis

DrPhilG wrote: »

Well I'm buying 2 x 16s, since they're on offer and therefore cheaper than the 32.

As for what else is needed, see my previous list of questions as that's what I'm just clarifying before proceeding.

So you end up with 20kWh new?

DrPhilG

sebdavis wrote: »

So you end up with 20kWh new?

Pretty much, although I think they'll be set up as 80q depth of discharge so about 16kWh usable.

championc

First of all, the batteries are delivered straight to your door, via UPS.

It would possibly be easier and safer to have the batteries on the attic floor rather than trying to build shelving, given their weight.

For the sake of the extra expense, I do think that you are better possibly going with a BMS or maybe just a balancer board per string. Rather than trying to get a 200ah BMS, you would more easily get 2 x 100's

On the safety size of thing, I possibly have an overkill setup. I have a Fuse, into a marine switch, into a DC MCB

1. Inline Fuse

2. Marine switch https://www.amazon.com/1-2-Both-Off-Disconnect-Waterproof-Isolator-1250Amps/dp/B07HT44MP5

3. MCB - I'm not sure if you can get bigger than 63A. Rather than protecting from the battery into the inverter, I use this to protect in the opposite direction !!!

The marine switch has 4 positions - Off, 1, 1&2 and 2. In other words, you can charge and discharge both or either strings or isolate them entirely. The lugs on this switch were quite solid, so if you go two strings, it's well worth the investment

With all the other questions and answers today, I'm not sure if all of your questions have been answered - but let me know if not

DrPhilG

championc wrote: »

With all the other questions and answers today, I'm not sure if all of your questions have been answered - but let me know if not

Oh there will be lots more, I've just placed the order...

32pc CALB 3.2v 200Ah LiFePo4 on the way and should reach me sometime in May.

Questions incoming in a sec...

DrPhilG

championc wrote: »

It would possibly be easier and safer to have the batteries on the attic floor rather than trying to build shelving, given their weight.

I was thinking of something similar to this. Would fit comfortably to the side of my inverter location, and easy to shift if/when I migrate to the garage. Also easy to build insulation around in winter.

championc wrote: »

For the sake of the extra expense, I do think that you are better possibly going with a BMS or maybe just a balancer board per string. Rather than trying to get a 200ah BMS, you would more easily get 2 x 100's

Could you clarify what you mean by" per string"? Is that each set of 16? I was liking graememk's idea of joining into blocks of 2 to join up as a 16 x double cell (if I understood that right). Suggested here:

graememk wrote: »

Or you could parallel every 2 cells together, you might need extra busbars. But you would only have to put a balance lead on each pair of batteries.

championc wrote: »

On the safety size of thing, I possibly have an overkill setup. I have a Fuse, into a marine switch, into a DC MCB

No such thing as too cautious. I'll get into more detail on those closer to the time.

championc wrote: »

I'm not sure if all of your questions have been answered - but let me know if not

Many many thanks to you and everyone else here offering their expertise.

Ps one more question:
If I ever do add more cells than the 16kWh or so that these will provide, would it make more sense to add them on the othe inverter? Given that the Solis can only charge the batteries at a 3kW max, would I be better off being able to charge 2 separate sets of batteries at that speed, in the event that I have a system capable of generating up to 12kw (more likely around 10.5), it would be better to be storing at a rate of 6kw than possibly only 3kw, exporting 6kw, using 500w and being stuck with a limit on the remainder.

If I did split into 2 batteries, can the Solis systems still combine the 2 totals?

DrPhilG

DrPhilG wrote: »

If I did split into 2 batteries, can the Solis systems still combine the 2 totals?

And more importantly, how does a 2 inverter setup work? If the battery on Inv 1 is full, and there is more generation on Inv 2, how does that generation get to the battery on Inv 1?

championc

What do you reckon your max load / discharge rate will be ? This is your starting point and decisions should all be based on this requirement.

If you got a 5kw hybrid inverter, while it can discharge 5kw of solar power, you may need to confirm if it too can discharge 5kw from battery. However, if you only ever plan to discharge a max of 3kw, then you will have different options

DrPhilG

championc wrote: »

What do you reckon your max load / discharge rate will be ? This is your starting point and decisions should all be based on this requirement.

According to graememk's link, the max charge and discharge is 3kw.

I could have sworn I've seen it discharging more than 4kw though. I'll have a look through the app history to check.

Edit, just had a look and no, it doesn't seem to charge OR discharge at more than 2.4kw.

graememk

DrPhilG wrote: »

According to graememk's link, the max charge and discharge is 3kw.

I could have sworn I've seen it discharging more than 4kw though. I'll have a look through the app history to check.

Edit, just had a look and no, it doesn't seem to charge OR discharge at more than 2.4kw.

I have heard some of the newer hybrids can do 5kw from battery, if you can dig out the manual for yours it will tell you for sure.

The 2.4 is a battery limit not the inverter. but if you had a third, you'd prob only reach 3kw.

DrPhilG

On a side note, the BSL-battery crew came back to me, $2400 for a single 10kWh unit landed in Dublin. That's about €2k. Would then need to pay duty, plus transport from Dublin to Donegal. So looking at around €2.5k easily.

samdeluxjones

DrPhilG wrote: »

On a side note, the BSL-battery crew came back to me, $2400 for a single 10kWh unit landed in Dublin. That's about €2k. Would then need to pay duty, plus transport from Dublin to Donegal. So looking at around €2.5k easily.

After VAT, duty and delivery the BSL €2,600-€2,700 ish.

9.6kWh pylon from Dublin wholesaler named previously including VAT & delivery was haggled down to €3,100.

So only a saving of €4-500 at the end of the day.

Does inverter size matter to battery size? As in will a 5kW inverter will charge a 10kW battery?

DrPhilG

samdeluxjones wrote: »

Does inverter size matter to battery size? As in will a 5kW inverter will charge a 10kW battery?

It will charge any capacity, the only limit is on the speed it will charge at.

Deagol

graememk wrote: »

I have heard some of the newer hybrids can do 5kw from battery, if you can dig out the manual for yours it will tell you for sure.

The 2.4 is a battery limit not the inverter. but if you had a third, you'd prob only reach 3kw.

This is something that keeps getting missed. I see a lot of those Pylontech batteries for instance being quoted but they have a rather low discharge limit (the 4.8kw for instance only does 2.4kw max discharge).

Do we know is this a result of the battery makeup etc? Or is it simply down to conservative BMS settings? For myself, I paid slight bit more for a Puredrive - I worked out that in summer it means I can potentially discharge the battery 2x fast and fill it back up again in the same day. In practise I'm not sure how useful it will actually be but the price differential was very small.

EDIT: Leading on from someone elses comment, disappointed to find they are correct and my inverter doesn't output more than 3kw from the battery

2nd Edit: Tested it today. Battery (5kw) at 40% charge. Turned on 6.2kw devices in the home and the battery topped out at 3.2kw with rest coming from solar (0.66kw) and grid.

E30M3

samdeluxjones wrote: »

After VAT, duty and delivery the BSL €2,600-€2,700 ish.

9.6kWh pylon from Dublin wholesaler named previously including VAT & delivery was haggled down to €3,100.

So only a saving of €4-500 at the end of the day.

Does inverter size matter to battery size? As in will a 5kW inverter will charge a 10kW battery?

Was that the wholesaler starting with an 'M' or an 'S' and was that direct or via an installer? It seems like a good price and as you suggest not a lot dearer than the option from BSL

Thank you

samdeluxjones

E30M3 wrote: »

Was that the wholesaler starting with an 'M' or an 'S' and was that direct or via an installer? It seems like a good price and as you suggest not a lot dearer than the option from BSL

Thank you

Yup with a 'S' and was direct.

No there might be no issue whatsoever with BSL but it's a bit of a chance to take.

DrPhilG

As for selling the PylonTech, I don't have a clue on price. I've been watching them sell second hand on ebay UK for over £700 sterling.

Havent seen any for sale around here.

unkel

You can get them for around €750 brand new, incl. VAT. You'd need to pull a few strings for that though and use a trade account. But maybe try sell on FaceBook, plenty of people over there love overpaying for stuff. Put them up for €899 and see what you get

DrPhilG

unkel wrote: »

You can get them for around €750 brand new, incl. VAT. You'd need to pull a few strings for that though and use a trade account. But maybe try sell on FaceBook, plenty of people over there love overpaying for stuff. Put them up for €899 and see what you get

That was my thinking, people seem to be shelling out nearly full price for second hand ones on ebay so I'm sure I could shift them for €7-800.

Might just sell cheaper on here though, only fair considering the value of the advice I've had.

I'll cross the bridge of the new batteries first though.

sebdavis

DrPhilG wrote: »

That was my thinking, people seem to be shelling out nearly full price for second hand ones on ebay so I'm sure I could shift them for €7-800.

Might just sell cheaper on here though, only fair considering the value of the advice I've had.

I'll cross the bridge of the new batteries first though.

How big is the battery?

DrPhilG

sebdavis wrote: »

How big is the battery?

I have 2 x 2.4kWh units.

sebdavis

DrPhilG wrote: »

I have 2 x 2.4kWh units.

Forgive my ignorance but can you not just re-use them? along with the new batteries....Or are you limited to the number of strings connected?

graememk

sebdavis wrote: »

Forgive my ignorance but can you not just re-use them? along with the new batteries....Or are you limited to the number of strings connected?

Can't mix and match different battery makes, different communication protocols etc