WHY Greenrich Battery is 1.5C battery?

[Bruce Gu]

Statement: Addressing Misconceptions About Our 1.5C Battery for Residential Solar Energy Storage

We have recently become aware of claims that Greenrich battery, particularly our signature 1.5C battery, are unsuitable and unfit for the residential solar energy storage market. We would like to refute these statements with solid facts supported by our years of dedicated research and experience in this field, and to ease these rumors.

The circulating misbelief about the detrimental effects of 1.5C charging and discharging, leading to the degradation of battery performance and lifespan, can be easily addressed. The key factor that causes the decrease in cell cycle life is the excessive heat generated during charging and discharging, leading to high temperatures of the battery cell. Therefore, the solution is straightforward—either reduce the heat generated during the charging and discharging process, or increase the efficiency of heat dissipation. By doing so, the cell cycle life of batteries with higher discharge rates, such as our 1.5C batteries, can be easily maintained.

Addressing our solutions in turn, it is true that certain battery cells are only suited to deliver low currents because of their high internal resistance, which leads to the generation of excessive heat when forced to run at a high current. Imagine electrons as cars on a road: forcing cars to drive fast on a narrow road would be dangerous and reckless, as the road is designed for slow speeds. However, driving at higher speeds on a highway would not be a problem. The same principle applies to a cell. Forcing a 0.5C cell to run at 1.5C would surely cause overheating and degradation of battery performance and lifespan. However, if the cell is designed, with adequate, backed-up research, to be of low internal resistance—such as our 1.5C cells—it can run on high currents without producing excessive heat, thus solving the problem of defective, malfunctioning cells.

Moreover, regarding heat dissipation, please refer to the table below comparing the specifics of cells from different companies, which compares the surface areas of battery cells for every wattage generated, for the same discharge rate:

Cell Model	Company-E 4.6Ah	Company-A 63Ah	Company-B 280Ah
Cell Form Factor	Cylindrical	Prismatic	Prismatic
Capacity (Ah)	4.6	63	280
Surface Area/Power (mm²/W)	74	42	16

As shown, the 1.5C battery adopts a 4.6Ah cylindrical cell, which provides a sufficiently larger surface area for heat dissipation compared to other energy storage batteries that use a prismatic cell. Our 1.5C cells are able to maintain a significantly low temperature during the charging and discharging process, ensuring a prolonged cell cycle life.

Therefore, by selecting the right products and cells for your home energy storage, a 1.5C discharge with 6000 cycles is certainly possible and not overcommitted.

We remain committed to providing reliable, high-quality energy storage solutions and appreciate your continued trust in our products.

and welcome all to join the discussion about Facts of lithium battery, including life span, safety, etc..

[JayMardern]

5 hours ago, Bruce Gu said:

 

We have recently become aware of claims that Greenrich battery, particularly our signature 1.5C battery, are unsuitable and unfit for the residential solar energy storage market. We would like to refute these statements with solid facts supported by our years of dedicated research and experience in this field, and to ease these rumors.

 

From where are these claims?

Almost all feedback around here on Greenrich is positive...

Edited July 24 by JayMardern

[zivva]

Got the data sheet from the manufacturer of those cylindrical 1.5C / 6000 cycles cells or is it just a marketing claim ?

The problem with high C-rate (anything above 0.5C being the standard in energy storage industry) in general not being only degradation due to temperature but also mechanical stress on electrode particules.

Any case, Greenrich brochures mention "for better battery life, we suggest charge & discharge @ 0.5C @ 25°C"

Edited July 24 by zivva

[P1000]

I have measured these and they will increase in temperature 4x faster than Pylontech's 0.5C batteries at the same C-rate of discharge (the greenrich has 4x the internal losses of an equivalent pylontech). I would not use them at a higher rate than 0.8C, preferably 0.5C.

The claim about the cell surface area is useless when it's re-packaged in the same form factor.

Edited July 25 by P1000

[Bruce Gu]

9 hours ago, P1000 said:

I have measured these and they will increase in temperature 4x faster than Pylontech's 0.5C batteries at the same C-rate of discharge (the greenrich has 4x the internal losses of an equivalent pylontech). I would not use them at a higher rate than 0.8C, preferably 0.5C.

The claim about the cell surface area is useless when it's re-packaged in the same form factor.

Cell surface make big difference subjectBattery inside.pdfBattery inside.pdfBattery inside.pdf how to be packed. the PDF documents show the different between Greenrich and other batteries.

[Bruce Gu]

On 2024/07/24 at 3:31 PM, JayMardern said:

From where are these claims?

Almost all feedback around here on Greenrich is positive...

Somebody tried to bad mouth of Greenrich

[zivva]

8 hours ago, Bruce Gu said:

Somebody tried to bad mouth of Greenrich

Not really, just interested & looking for more informations then facts.

Facts at this point are :

- Greenrich does not produce any battery but use the services of a Chinese OEM : Greenway. Nothing wrong with that, it is how technology works these days. Greenrich does not try to hide it : it is written on a sticker of your products & the PDF you attached.

- Greenway (because at this point, Greenrich is nothing else but a marketing brand put on a sticker ...) does not produces battery cells but assemble battery packs using third party cells. Both for NMC & LFP markets :

https://www.greenway-battery.com/about.html

 

Awaiting a datasheet to back up Greenrich marketing statement but looking at the photos you presented in your PDF, here are the specs of the cells you presented : 

https://www.haicenpower.com/products_dt/31.html

3000 cycles @ 100% DOD, 6000 cycles @ 80% DOD. Both ar 0.5C / 25°C per industry standards.

So ...

[Nexuss]

22 hours ago, P1000 said:

the greenrich has 4x the internal losses of an equivalent pylontech

Is that really correct? how can it be that bad? 

[P1000]

1 hour ago, Nexuss said:

Is that really correct? how can it be that bad? 

From my experiments it looks like pylontech just has better cells. (and for 4 times more losses, you only need double the internal resistance)

[P1000]

14 hours ago, Bruce Gu said:

Cell surface make big difference subjectBattery inside.pdfBattery inside.pdfBattery inside.pdf how to be packed. the PDF documents show the different between Greenrich and other batteries.

Cell surface make no difference when you pack the cells closely like that and into a box with the same surface area. The box surface becomes the limiting factor. Packing those cells close is the same as a big cell - unless you have water cooling or similar running between them (like tesla).

Don't get me wrong - Greenrich is a perfectly adequate battery, and I can recommend them, but the claim that the smaller cells have any advantage in this case is nonsensical. The only reason that they use them is because they are cheaper.

Edited July 26 by P1000

[Bruce Gu]

Some competitors says that Greenrich is 1.5C discharging rates battery, 1.5C discharging will affect the lifespan. I want to give a example: 

Think of Buying an Energy Storage System Like Buying a Car for Your Family

Imagine you have a Mercedes-Benz. Its speedometer shows it can go up to 280 km/h. This means the car is designed and tested to reach that speed safely. However, most drivers won’t go that fast. When driving at 120 km/h, a Mercedes-Benz is smooth and comfortable. When you need to overtake another car, it accelerates quickly and easily.

Greenrich batteries work in a similar way. They are designed to handle a high discharge rate of 1.5C, meaning they can safely provide a lot of power quickly. But in most cases, you won’t need that much power. Usually, they run at less than 1C or around 0.5C. When you do need a lot of power, like when running many appliances at once, Greenrich batteries can handle it without shutting down. When running fewer appliances, they operate smoothly. Even when the power demand goes up and down, like when you turn on an air conditioner, Greenrich batteries stay reliable and don’t overload. Tests show that using the batteries at high power for short times doesn’t significantly shorten their life.

So, just like a Mercedes-Benz gives you a great driving experience at different speeds, Greenrich batteries give you reliable performance in all kinds of power situations.

[TheMac]

1 hour ago, Bruce Gu said:

Tests show that using the batteries at high power for short times doesn’t significantly shorten their life

What will using the batteries at high power for long periods do, though?

It is fine to say that the batteries can go to 1.5C discharge and then add the phrase "for short times" but can it run at or close to 1.5C discharge for longer periods? Where is the sweet spot? If the manufacturer is honest it will indicate where that sweet spot sits and if it is at 1C or even 0.5C then it would be hard to convince me that anything more for longer periods is a good idea.

Greenrich UP5000 manual says:

Greenrich UP5000 brochure says:

They don't agree whether it be 48A or 43A but even if there is a reason for that discrepency they still both say "For better battery life cycles, we suggest charge/discharge at 4xA (0.5C @25°C)". Does this "better battery life cycles" mean that I will get much, much more than 6000 cycles if I use it only at 0.5C for long periods and close to 6000 cycles if I use it at 1.5C for long periods or does it mean I will only get more than 6000 cycles if I use it only at 0.5C for long periods and much less than 6000 cycles if I use it at 1.5C for long periods? Devil in the details?

On 2024/07/24 at 2:48 PM, Bruce Gu said:

We have recently become aware of claims that Greenrich battery, particularly our signature 1.5C battery, are unsuitable and unfit for the residential solar energy storage market.

I own 2 x Greenrich UP5000 on two installations and I like them. I charge at 20A and have my inverter set to 70A discharge which I never reach. I am not an expert on batteries but to my limited knowledge they are good. I am sure most here will not say they are unsuitable. @JayMardern also said so.

1 hour ago, Bruce Gu said:

Greenrich batteries give you reliable performance in all kinds of power situations

I agree but does that reliable performance give me >6000 cycles at 1.5C the same as >6000 at 0.5C? I see performance here as delivering the required power, not lifespan.

So if you want to refute claims made by some out there that Greenrich Batteries are unsuitable then I stand by you. If you want to claim that Greenrich batteries can discharge at 1.5C for short periods of time, sure go ahead. But I do not think discharging/charging at 1.5C for longer periods is a good idea. You can reach 280km/h with the Merc but you may possibly end up wrecking your car or killing another motorist or pedestrian.

Edited July 30 by TheMac

[zivva]

Until proven otherwise by reading those magical & unique cells datasheet,you might need to try harder to convince anyone that those cells are rated for 1.5C discharge.

Meanwhile, one can only assume that those cells are rated as all other LFP cells available on the market : 0.5C @ 25°C. Assuming those cells are Grade A automotive cells. Tested & matched.

Greenrich markets their products as able to achieve 1.5C ... But only recommend 0.5C. That 1.5C is nothing more than some marketing gimmick ...

You are right though, a Mercedes can achieve 280 km/h (well, some AMG can, not sure about the Mercedes :p), but it's not meant to be driven at 280 km/h at all time. If ever that was possible At some point it even needs to stop.

.

[TaliaB]

At high-rate discharge, eg 1.5 C, the extraction of lithium ions from one electrode and intercalation to the other is too strong to be efficient. This damages the electrodes’ elasticity. Furthermore high rates increase the battery’s internal resistance. The battery will have to strive to deliver high current and use more power to keep the same voltage level, which will therefore make it age faster. For surge on inverters the 1.5c discharge comes in handy with inductive startup loads that only last a few milliseconds. Constant Charging/ discharging a 5kwh battery at 150A(7200w) will increase the temperature in the cells also speeding up the aging process.

No argument that the Greenrich lfp batteries are good quality but for longevity 0.5c charge/ discharge would be the wise decision. If more power is required rather install more capacity in parallel.