22 minutes ago, P1000 said:

I assume you are referring to a typical 5kWh battery - so lets say Hubble vs Pylontech. The Pylontech is capable of delivering 2.4kW continuously (0.5C) and the Hubble 5.1kW (1C). The capacity is not affected by the C rating - you can do 2 hours at 2.4kW on the Pylon, but 1 hour at ~5kW for the Hubble.

Is it then the case that you can actually run the Pylontech at 1C, but you only get backup for half as long?

Or does the BMS prevent this, or does it damage the batteries?

Edited May 14, 20224 yr by Bobster
Correct the battery name

9 minutes ago, Bobster said:

Is it then the case that you can actually run the Pylontech at 1C, but you only get backup for half as long?

Or does the BMS prevent this, or does it damage the batteries?

Nope, if one battery, it will trip with over current. BMS will shut down your battery,  You need 4 x US2000 to draw 100A continuous or 2 x UP5000 

On 2022/05/13 at 2:00 PM, Piper said:

I'm not sure at what point did the recommended charge /discharge current of the pylontech batteries become their limitations.

I have US 2000c and 3000c Max Discharge current is 50A and 74A that is 1C is it not?

 

Your four US2000 alone can discharge and charge at 100A, so YES! you have a bank that is capable of giving you more that 1C

2 minutes ago, hoohloc said:

Your four US2000 alone can discharge and charge at 100A, so YES! you have a bank that is capable of giving you more that 1C

But only for like 2-5 minutes or something ,not sure haven't tested that neither will i haha. From what i saw when i updated my US3000C 's firmware it looked like it will over-current fault if you are at 74 amps too long or a max of 90 Amps draw and that wil probably shut it down instantly.

Edited May 14, 20224 yr by Nexuss

3 minutes ago, Nexuss said:

But only for like 2-5 minutes or something ,not sure haven't tested that neither will i haha. From what i saw when i updated my US3000C 's firmware it looked like it will over-current fault if you are at 74 amps too long or a max of 90 Amps draw and that wil probably shut it down instantly.

One US2000 has a recommended charge/discharge of 25A, now a bank of four US2000 will give you 100A continuously. Add six US3000 to make a bank that @Piper has and see that you have way more than 1C. 

1 minute ago, hoohloc said:

One US2000 has a recommended charge/discharge of 25A, now a bank of four US2000 will give you 100A continuously. Add six US3000 to make a bank that @Piper has and see that you have way more than 1C. 

Almost but you are no phrasing it correctly,C rates dont work like that. 4 x 0,5C batteries in parallel does not equal 2C. Its still 0,5C.

2 minutes ago, Nexuss said:

Almost but you are no phrasing it correctly,C rates dont work like that. 4 x 0,5C batteries in parallel does not equal 2C. Its still 0,5C.

ok, let me re-phrase, since alot of people look at 1C batteries because they are after 100A charge and discharge, do you agree that you can get 100A charge and discharge with 4 x US2000? 

1 minute ago, hoohloc said:

ok, let me re-phrase, since alot of people look at 1C batteries because they are after 100A charge and discharge, do you agree that you can get 100A charge and discharge with 4 x US2000? 

Yes. For the US 2000 =

Continuous Discharge Rate (Normal Use):

1200 W

Maximum Discharge Rate (5 Minutes):

2400 W

Surge Discharge Rate (15 Seconds):

4800 W

Maximum Charge Rate (5 Minutes):

2400 W

2 minutes ago, Nexuss said:

Yes. For the US 2000 =

Continuous Discharge Rate (Normal Use):

1200 W

Maximum Discharge Rate (5 Minutes):

2400 W

Surge Discharge Rate (15 Seconds):

4800 W

Maximum Charge Rate (5 Minutes):

2400 W

Lets go back again, you have 4 x US2000, each can give you 25A continuous. Not for 5min or 15min, but continuous. Take a bank, made up of those four batteries, each giving 25A, and you have your 100A continuous supply. That is the same current you get from a 1C battery, right? same benefit right? You might have one battery that can give you 100A which is the same discharge I can get with my bank of four.  

1 minute ago, hoohloc said:

Lets go back again, you have 4 x US2000, each can give you 25A continuous. Not for 5min or 15min, but continuous. Take a bank, made up of those four batteries, each giving 25A, and you have your 100A continuous supply. That is the same current you get from a 1C battery, right? same benefit right? You might have one battery that can give you 100A which is the same discharge I can get with my bank of four.  

100% correct yes. (assuming the 1C battery is a 100Ah battery haha)

Edited May 14, 20224 yr by Nexuss

So as I expected, selecting a battery is not as simple as it seems.

What do we look for in a lithium battery, taking a few things into consideration, lithium technology is here today, but who knows what will be the next best thing in 2-5 years time, do you need a 10 - 20 year warranty or 6000 cycles, do you plan to live on the property for more than 5 years, will there not be better technology this year or next year 

Will the huge outlay for lithium batterie increase your property value, considering that in some case the outlay is R100K+, most people expect some sort of ROI. 

What must a person look out for when deciding on the battery type and capacity? 

1/ Wall or cabinet mounted, do you want a ugly looking battery hanging on the wall.

2/ The inverter capacity, charge and discharge rate compared to the battery. 

3/ Compatibility, will the battery communicate with the type of inverter you install?

4/ Backup, how long will the battery last. 

5/ Type of cells used in the battery.

6/ Type of BMS and thermal protection used in the battery.

7/ Switch isolator and overload protection.  

8/ Very, very important, battery operating temperature and cooling. 

 

Battery isolation and overload protection, do you really need a fuse on the + and - and do you need to isolate both +and -.

It seems everyone has just jumped on the double fuse and isolation method, but do you really need 2 fuses and a double pole switch disconnect. 

Is it a good idea to ground the neg - ? 

Looking at Victron manuals, there is only single pos. + switching a overload protection. 

Anyone know the reason people are wasting money on double and triple fuse isolators? 

Do lithium batteries not have some form of overload protection and and isolator built in ? 

 

25 minutes ago, isetech said:

So as I expected, selecting a battery is not as simple as it seems.

What do we look for in a lithium battery, taking a few things into consideration, lithium technology is here today, but who knows what will be the next best thing in 2-5 years time, do you need a 10 - 20 year warranty or 6000 cycles, do you plan to live on the property for more than 5 years, will there not be better technology this year or next year 

Will the huge outlay for lithium batterie increase your property value, considering that in some case the outlay is R100K+, most people expect some sort of ROI. 

What must a person look out for when deciding on the battery type and capacity? 

1/ Wall or cabinet mounted, do you want a ugly looking battery hanging on the wall.

2/ The inverter capacity, charge and discharge rate compared to the battery. 

3/ Compatibility, will the battery communicate with the type of inverter you install?

4/ Backup, how long will the battery last. 

5/ Type of cells used in the battery.

6/ Type of BMS and thermal protection used in the battery.

7/ Switch isolator and overload protection.  

8/ Very, very important, battery operating temperature and cooling. 

 

My inverter has built in configurations (including comms) for several brands. So with hindsight, I would want a battery that is compatible with my inverter. IE not something where you have to run without comms and rely on manual settings.  And it would have to have a distribution and support network in SA.

Or, as second prize, I would get an inverter and battery that SolarAssist or something similar can effectively provide the comms.

On 2022/05/14 at 2:07 PM, isetech said:

Tell us more about your batteries, price, KWH, C rating HR rating,etc.

BSLB 6.4kwh each. 1C discharge. R36500. 125AH

On 2022/05/14 at 12:04 PM, isetech said:

 I am still trying to understand why a person would spend R20-25 K on a C0.5 rated battery ? Why would you spend R40k on 2 x C0.5 rated batteries to get same capacity of a C1 rated battery? 

It just seems crazy, maybe it has to do with the cycles or there must be something.

What am I missing ? 

 

 

 

Capacity is related to energy storage = kWh

C is related to the rate at which you can release or put back that energy = charge and discharge rate (kW).

You can increase both by placing batteries in parallel. But if you have a tight budget and can only afford one battery, you need to be aware of its charge / discharge limitations. Although a battery may have the storage capacity of say 4.8 kWh, you may only be able to draw (and possibly charge) 2.4kW (50A@48V) continuously from it (0.5C). If the same 4.8kWh battery is capable of 1C, then you can draw and charge it at 100A@48V =4800W or 4.8K. Clearly the latter option is better suited to a 5K inverter.

If your budget is a bit better, you can buy another 4.8 kWh battery (same model and manufacturer) and place it in parallel. Now you will have 9.6kWh storage, and you will be able to discharge and charge at 4.8kW (50A+50A@48V). So it's better because discharge and charge rate is closer to your inverter spec (5kW).

If you bought 1C batteries in the two battery scenario above, the advantage is that they will last far longer because your discharge and charge rates are at 0.5C and therefore far lower than the maximum specified by the manufacturer.

Edited May 15, 20224 yr by YellowTapemeasure

On 2022/05/14 at 2:04 PM, isetech said:

 I am still trying to understand why a person would spend R20-25 K on a C0.5 rated battery ? Why would you spend R40k on 2 x C0.5 rated batteries to get same capacity of a C1 rated battery? 

It just seems crazy, maybe it has to do with the cycles or there must be something.

What am I missing ? 

 

 

 

1C is significant when people are on a budget

5 hours ago, Leshen said:

1C is significant when people are on a budget

I could  understand if the 0.5 C was half the price, why would you buy a 5KWH  0.5C for almost the same price as a 5 KWH 1 C battery? 

10 minutes ago, isetech said:

I could  understand if the 0.5 C was half the price, why would you buy a 5KWH  0.5C for almost the same price as a 5 KWH 1 C battery? 

The other issue is when you pair say a 5kw Sunsynk with 1 5kwh 0.5c battery, you will only get 2500w. Now during a grid failure, you can’t even turn a microwave or a kettle on. So I prefer a functional system 

1 hour ago, isetech said:

I could  understand if the 0.5 C was half the price, why would you buy a 5KWH  0.5C for almost the same price as a 5 KWH 1 C battery? 

Because some people around are playing scaremongering games with the chemistry of a well known 5kWh 1C battery brand. 

22 minutes ago, PowerUser said:

Because some people around are playing scaremongering games with the chemistry of a well known 5kWh 1C battery brand. 

And that’s without giving the manufacturer a chance to rectify whatever issues they have 

Reading through some battery data for a SLA battery compared to a lithium.

If I understand this correct, some lithium batteries can operate at 0.5C and some at 1C. A flooded lead acid battery only has a 0.05C rating, so you would need a lot of lead acid batteries to get the full value of a Sunsynk inverter. 

I found this rather interesting.

 

https://www.power-sonic.com/blog/what-is-a-battery-c-rating/#:~:text=The battery C Rating is,10 Amps for one hour.