Investigating Lithium battery generators

[jonathan.agnew]

LiFePO4 batteries for powerwalls are specified for 20 years / 6000 cycles, about right for powerwall applications.

But where would be a reputable place to buy say 10 kwh (and how does the weight compare to lithium ion, in case one want to say slot it into a microcar)?
Edit - answering my own question (in a sense) there is alibaba (if one's feeling brave)

https://diysolarforum.com/threads/recommendations-for-what-where-to-buy-lifepo4-cells.35993/

and I gather it's circa 80kgs (not bad)

 

[Nealh]

Those modules are EVE LF280K, Grade A 3.2v 280ah lifepo4 moudule is £150 from a UK supplier but one needs 4 to make a 12v battery or 8 for use with 24v panels. Add a £60 /£80 smart BMS with individual BT or uart cell reading cost is £1370 for 24v 280ah or 6.72kwh/6720wh.
The more module one buys the cheaper they are.

Cycle life is 6000 cycles at 0.5c charged at 0.5c or 140a, one isn't likely to see that with panel charging. Discharge is max 1c a again a huge 280a something one won't get near for home use.

Lifepo4 modules makes so much more sense for a static /powerwall set up over lion, should a lifepo4 module fail one can simply unbolt it and replace it. Making ones own out of modules is cheaper by a long chalk but one only gets a 1 year warranty on the modules.
The powerwalls sold by makers are up to or more then £10k but one gets a 10yr warranty.

 

[WheezyRider]

This calculator I found may be useful:

Benefits Of Solar Calculator | Low Energy Supermarket Ltd.

The solar calculator can be used to help you choose the best order of solar panel power output & battery storage capacity. For further details, visit our website!

lowenergysupermarket.com

 

[soundwave]

Y.Cube 1MW 60 minutes | Aggreko UK

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www.aggreko.com

 

[jonathan.agnew]

Those modules are EVE LF280K, Grade A 3.2v 280ah lifepo4 moudule is £150 from a UK supplier but one needs 4 to make a 12v battery or 8 for use with 24v panels. Add a £60 /£80 smart BMS with individual BT or uart cell reading cost is £1370 for 24v 280ah or 6.72kwh/6720wh.
The more module one buys the cheaper they are.

Cycle life is 6000 cycles at 0.5c charged at 0.5c or 140a, one isn't likely to see that with panel charging. Discharge is max 1c a again a huge 280a something one won't get near for home use.

Lifepo4 modules makes so much more sense for a static /powerwall set up over lion, should a lifepo4 module fail one can simply unbolt it and replace it. Making ones own out of modules is cheaper by a long chalk but one only gets a 1 year warranty on the modules.
The powerwalls sold by makers are up to or more then £10k but one gets a 10yr warranty.

Very helpful info, but why only static? Why wouldn't say a £3k 20kwh pack be a useful range extender for something like an old leaf?

 

[Benjahmin]

I had kinda got the idea that LifePo4 might be the better battery for this usage, where weight was not such an issue. However, there seems to be a confusing array of manufacturer terminology where battery type is concerened. For instance the Delta Pro unit I linked to states that the battery chemistry is 'LFP'. What's that then ?
I think I would favour a fully manufactured unit so I don't have to mess around with a bms with the possibility of getting it disasterously wrong through limited knowledge.

 

[Woosh]

For instance the Delta Pro unit I linked to states that the battery chemistry is 'LFP'. What's that then ?

it's the same as LiFePO4 (Lithium Iron Phosphate). LPF stands for Lithium Ferro Phosphate. Neither name is ideal because the cathode material is a compound of LiFePO4 and other elements like Aluminium, Cobalt, Manganese and Titanium. The compound forms a solid structure of 'blobs' a bit like rockwool. The gaps between the blobs hold the free Lithium making the substance suitable for use as batteries. The main advantage of this chemistry is the electrolyte in those batteries is aqueous and does not combust.

 

[WheezyRider]

I had kinda got the idea that LifePo4 might be the better battery for this usage, where weight was not such an issue. However, there seems to be a confusing array of manufacturer terminology where battery type is concerened. For instance the Delta Pro unit I linked to states that the battery chemistry is 'LFP'. What's that then ?
I think I would favour a fully manufactured unit so I don't have to mess around with a bms with the possibility of getting it disasterously wrong through limited knowledge.

If you want a LiFePO4 battery with a BMS, they are a little more expensive than building one yourself from modules, but not by a huge amount:

Lithium Batteries At Affordable Range

Lithium Batteries offer up to 5x the power of regular equivalents which makes them perfect for use in high-drain devices. Contact us to buy these batteries at the best prices!

lowenergysupermarket.com

There are also cheaper ones on eBay with brands that are not so well known.

 

[Nealh]

Stand alone LFP, over £470 for 100ah 12v battery with smart reading.

£280 buys 4 x 105ah modules for 12v and add £70 for a smart bt/uart bms is nigh on a third cheaper.
£531 buys 8 x 105ah modules 12v 210ah or 24v 105ah, both options far better then the stand alone battery.
24v would be better if one is using 24v panels.

For most ebikers who understand paralleling and series as well as ah/wh etc ,etc modules are a good way to go and a more cost effective solution.

 

[Nealh]

LFP is often used now as it is easier to write or say vs doing so with lifepo4.

 

[Benjahmin]

So, yesterday's announcement from national grid is focusing the mind somewhat. This is the first mention of the possibility of power cuts (stated as worse case - unlikely ?) and giving maximum duration of 3 hours. Seems fairly specific for something that's unlikely ! Colour me sceptical.
So I've had another look at this. Elsewhere Bluetti are mentioned as having lfp batteries, had a look and they seem good units. Looking again at these Delta Pro units. Also lfp but with the ability to achieve auto change over in the event of mains failure. However haven't, as yet, found a price or spec for that particular unit/function. Their array of products is confusing as is their mixed referencing of watts, watt hours and amperages whilst referencing generators in amongst.
Just found the smart panel, it's another £1400 plus £39 for every relay plugged into it. So with a base level £3500 for the battery unit of 3.6KWh (It's possible that at least one other unit would be needed) that's coming to £4980 + installation costs.
I am a qualified electrician but trained many years ago, I'm aware this may be beyond me on safety grounds.
Maybe back to power walls ?!

 

[WheezyRider]

So, yesterday's announcement from national grid is focusing the mind somewhat. This is the first mention of the possibility of power cuts (stated as worse case - unlikely ?) and giving maximum duration of 3 hours. Seems fairly specific for something that's unlikely ! Colour me sceptical.
So I've had another look at this. Elsewhere Bluetti are mentioned as having lfp batteries, had a look and they seem good units. Looking again at these Delta Pro units. Also lfp but with the ability to achieve auto change over in the event of mains failure. However haven't, as yet, found a price or spec for that particular unit/function. Their array of products is confusing as is their mixed referencing of watts, watt hours and amperages whilst referencing generators in amongst.
Just found the smart panel, it's another £1400 plus £39 for every relay plugged into it. So with a base level £3500 for the battery unit of 3.6KWh (It's possible that at least one other unit would be needed) that's coming to £4980 + installation costs.
I am a qualified electrician but trained many years ago, I'm aware this may be beyond me on safety grounds.
Maybe back to power walls ?!

£3.5k for 3.6 kWh is a p*ss take.

Not sure what to make of the announcement...could be scaremongering, or could be preparing the ground for much bigger power outages...

Solar and batteries probably not worth bothering with in winter. Best option may be to go for a 3kW generator.

 

[Benjahmin]

Found a company called Naked Solar. Tried to contact them about a battery installation but on their contact page was an apology.
They say they they re-opened their enquiry page on September 2nd and have been so deluged that they've had to close it again until january 3rd 2023 !
Looks like a lot of people are starting to think somethings not quite right.......
May have to look at a generator but, living in a terrace, noise will be an issue.

 

[Benjahmin]

Still trying to find my way through this.
Just contacted a Coventry firm called Voltaconsolar. They sent me some useful schematics.
On the face of it, standalone lithium 'generators' happen to be priced at around £1/Wh storage, which looks expensive. However they do contain chargers and inverters plus all outlets on board but do not have an auto changeover facility.
Buying a domestic battery to be installed would be much cheaper/Wh storage but I would have to have a second inverter/charger and make significant alterations to the house installation to allow power to be used during power cuts, adding significant costs.

After reading another thread where someone was using a Bluetti EB70, I found this

BLUETTI AC200P Portable Power Station | 2,000W 2,000Wh

Meet all your needs, anywhere, anytime. BLUETTI AC200P UK solar generator features a massive 2,000Wh capacity to power your equipment, no more worry about power outages interrupting your work.

bluettipower.co.uk

This would more than service my domestic needs and have the ability to be used out and about when in the van camping. At 2KWh it should just about charge the 3 bike batteries we use if used with a 200w solar array. At 26kg it's no light weight but doable.
Still lots of dough though which is making me review what it is I'm actually trying to achieve.

 

[Nealh]

And for the same money or less one can, if they are able to simply series & parallel modules together have a 6720wh battery at 12v or a 3360wh one at 24v with a BT BMS and an inverter. If only wanting a 12v set up then 3360wh is under £1000.


LFP Modules are easy all one has to do is link 4 x 12v modules in series using the buss interconnectors via nut and bolts. Stick a terminal block fuse on the + output of the battery. A simple 4s BMS is easy to fit and one doesn't need to
solder, crimp ring terminals to each BMS sense wire and simply nip up under the buss nut .

 

[Woosh]

So, yesterday's announcement from national grid is focusing the mind somewhat. This is the first mention of the possibility of power cuts (stated as worse case - unlikely ?) and giving maximum duration of 3 hours. Seems fairly specific for something that's unlikely ! Colour me sceptical.
So I've had another look at this. Elsewhere Bluetti are mentioned as having lfp batteries, had a look and they seem good units. Looking again at these Delta Pro units. Also lfp but with the ability to achieve auto change over in the event of mains failure. However haven't, as yet, found a price or spec for that particular unit/function. Their array of products is confusing as is their mixed referencing of watts, watt hours and amperages whilst referencing generators in amongst.
Just found the smart panel, it's another £1400 plus £39 for every relay plugged into it. So with a base level £3500 for the battery unit of 3.6KWh (It's possible that at least one other unit would be needed) that's coming to £4980 + installation costs.
I am a qualified electrician but trained many years ago, I'm aware this may be beyond me on safety grounds.
Maybe back to power walls ?!

I am astonished at the price of these powerwalls. As Nealh said, they are not sophisticated technology and the components (batteries, inverters, chargers) are widely available. I don't get it.
It seems that those companies try to exploit the fear factor.

 

[Nealh]

End of the day it depends on how mobile one wants the battery, at 26kg it isn't something one will want to heft about to often.
LFP module are 5.25kg each.

For most lithium batteries are the unknown but there is nothing special about connecting them. The prices seen for some Li systems/batteries is just pure greed witht he pricing.

 

[Nealh]

£3.5k for 3.6 kWh is a p*ss take.

Totally agree, obscene profiteering.
Esp as one can buy the similar capacity for at least if not cheaper a third of that price.

Even a stand alone LFP leisure battery of 3.6kwh is a third of that price or a 5.52kwh battery comes in at under half that price.

 

[WheezyRider]

Totally agree, obscene profiteering.
Esp as one can buy the similar capacity for at least if not cheaper a third of that price.

Even a stand alone LFP leisure battery of 3.6kwh is a third of that price or a 5.52kwh battery comes in at under half that price.

Can get 3.8kWh leisure battery with smart functions for a grand:

Lithium Batteries

The Fogstar Drift range of leisure batteries contain the very best EVE Grade A Prismatic Lithium Iron Phosphate (LiFePO4) cells, integrated JBD Battery Management System (BMS), built-in Heating, Bluetooth and Fogstar Drift App for external battery management.

www.fogstar-drift.co.uk

 

[Woosh]

what is the economic case of a powerwall?
Let's say you charge your powerwall at night tariff (10p/kwh between 23:30 and 5:30) and use it in the day (44p/kwH). Maximum savings for a 10kwH powerwall: 34p*10 = £3.40. Let's say on average you get about 2/3 of that, £2.25 at the moment but when the crazy gas price is over, the saving may be half that.
I reckon the cost of a 10kwH powerwall should be about £1500-£2000 to make economic sense.