Hi Guys,

Would appreciate you advice,

I am ready to purchase more storage as I currently have 1 Pylontech.

Looking at spending about 30k on storage. I could either buy 2 x extra Pylontech us3000c

Or look at a different brand and selling my current Pylontech.

My setup:

5kva Growatt SPF5000ES

9 x 455W JR Panels 

1 x Pylontech us3000c

My usage is about half of what my panels can supply, so I think I will have enough to charge extra batteries,

even if it charges off Utility.

I see the Pylontech is rated at 75Ah.

What would you recommend?

Thanks.

 

 

 

 

There are not a lot of options that beat the pylon on price per Wh (that I am aware of and are not DIY solutions). Others usually offer more in terms of current capacity, but if you have 3 pylons that should not be an issue. Pylontech also fares very well in the long term tests.

https://batterytestcentre.com.au/reports/

Edited October 29, 20214 yr by P1000

31 minutes ago, roadkill said:

Hi Guys,

Would appreciate you advice,

I am ready to purchase more storage as I currently have 1 Pylontech.

Looking at spending about 30k on storage. I could either buy 2 x extra Pylontech us3000c

Or look at a different brand and selling my current Pylontech.

My setup:

5kva Growatt SPF5000ES

9 x 455W JR Panels 

1 x Pylontech us3000c

My usage is about half of what my panels can supply, so I think I will have enough to charge extra batteries,

even if it charges off Utility.

I see the Pylontech is rated at 75Ah.

What would you recommend?

Thanks.

 

 

 

 

How much are you selling the one Pylontech? if you decide to sell, I'll take it from you  😃

Thanks for the reply P1000, I am leaning towards getting more Pylontechs 🙂 Interesting document, yes the pylons do fare well long term

Hoohloc, not sure yet, the battery is about 1 year old, still researching. 

Not sure if it is better to get 1 big battery, or more smaller batteries in a bank.

If i go with more pylons i will need to purchase a rack as well

 

1 hour ago, roadkill said:

Thanks for the reply P1000, I am leaning towards getting more Pylontechs 🙂 Interesting document, yes the pylons do fare well long term

Hoohloc, not sure yet, the battery is about 1 year old, still researching. 

Not sure if it is better to get 1 big battery, or more smaller batteries in a bank.

If i go with more pylons i will need to purchase a rack as well

 

The good thing about getting smaller batteries in a bank as opposed to just one big battery, is that when one fails, you still have few to run on. One big one fails, you will be left without a battery for a long time while trying to get that sorted out. 

You do not really need to purchase a rack, you can get the brackets and stack the batteries  like I did in the photo below 

Thanks that does make sense,

I do have a set of those brackets already for my current one that i never used.

Was thinking of the rack in order to bolt it to the wall and lock it, incase I have unexpected visitors.

But that would certainly be a cheaper option.

I am also looking for a device that sets off a beep/siren when Utility goes off (which is frequent in my area)

Generally what happens is i dont know its off and then I run items i shouldn't while on battery only. Like aircon, kettle.

How do you deal with that problem. The Shinephone app does not have functionality with the Growatt to notify me.

16 minutes ago, roadkill said:

Thanks that does make sense,

I do have a set of those brackets already for my current one that i never used.

Was thinking of the rack in order to bolt it to the wall and lock it, incase I have unexpected visitors.

But that would certainly be a cheaper option.

I am also looking for a device that sets off a beep/siren when Utility goes off (which is frequent in my area)

Generally what happens is i dont know its off and then I run items i shouldn't while on battery only. Like aircon, kettle.

How do you deal with that problem. The Shinephone app does not have functionality with the Growatt to notify me.

What I did, I installed a relay, this one (https://hager.com/uk/products/h/epn525-latching-relay-2nc2no-230v), the two NO contacts are wired to my stove and Geyser. Then one N/C contact is wired to pilot light. The relay is mounted in my DB and the pilot light is below the DB. The Coil of the relay is wired directly to my incoming supply, grid/Eskom. When grid drops, the relay switch off and disconnect the stove and geyser so that they can not run from batteries and the pilot light gets switched ON to indicate that there is no grid supply. When you are in the kitchen, you will automatically see that there is loadshedding when the clock on the oven is OFF. So no one is allowed to use the kettle, microwave or dishwasher if there is no sun 

I have the same inverter and mine is installed inside the house and I used to get annoyed when it beeped but now I appreciate the design since when I'm at home if I hear it beep and it midday I know the grid is off. 

If it beeps at sunset I have to go to the kitchen and check the stove if it sunset or loadshedding.

What I'm trying to say is that the inverter has the notification sound built in if you installed it where you can hear it.

thanks guys, my setup is a bit different as I have 2 little cottages with my mom and gran staying in there.

So utility goes off, they dont know either and will use things they are not supposed to like aircon.

They do have gas stoves, so no electric kettle.

Will have a look at the relay thanks.

Buyeye - Thanks, my invertor doesn't beep when grid goes off, going to check the manual to see if there is an option as i think it is disabled.

The first solar guys installed it in my hallway, thing sounds like a damn vacuum cleaner, when my install was redone, i moved it to another spot in the house where i can close the door and i dont have the sound of a vacuum cleaner XD

ps the cost of the little brackets works out almost the same as buying a rack when i eventually get to 4 batteries, something to consider when expanding

Setting 17.

17 hours ago, roadkill said:

ps the cost of the little brackets works out almost the same as buying a rack when i eventually get to 4 batteries, something to consider when expanding

The thing I hate about racks is the heat build up if they do not have fans and not in temp controlled room. My batteries are in the garage and it is already hot in there, so using a rack will mean my battery temps will be high which in turn will accelerate the deterioration. I find racks are better suited in server rooms where you have aircondition. But this is just my opinion 

Thanks you have a good point there hoohloc. Buyeye I did find setting 17, weird thing it only beeps when power is restored.

Found this little device, going to give it a shot, says you can connect an external siren to it as well:

Check this out on takealot: ESP Power Alarm
https://www.takealot.com/esp-power-alarm/PLID73025454

On 2021/10/30 at 9:27 AM, hoohloc said:

The thing I hate about racks is the heat build up if they do not have fans and not in temp controlled room. My batteries are in the garage and it is already hot in there, so using a rack will mean my battery temps will be high which in turn will accelerate the deterioration. I find racks are better suited in server rooms where you have aircondition. But this is just my opinion 

I whipped the door off my rack and stuck a Clicks fan in front instead. Battery temperatures still build up (it's ambient temperature after all), but it takes a whole lot slower, instead of peak temperatures at 12H30, they now peak at 16H00.   

40 minutes ago, YellowTapemeasure said:

I whipped the door off my rack and stuck a Clicks fan in front instead. Battery temperatures still build up (it's ambient temperature after all), but it takes a whole lot slower, instead of peak temperatures at 12H30, they now peak at 16H00.   

So what is the ideal temp? All the charts usually show battery levels at 25 degree C.

Even when quoting the long term expected working life - they state this at 25 decree C.

From Pylontech manual:

From BSL spec sheet:

 

@87 Dream I'm still struggling to understand the concept of DOD and I want to make sure I am not stressing my battery, in other words not shortening it's life span 

I make use of the battery every day from fully charged to discharge level of 48 V as per OEM.

Battery is a 100 AH, 51.2 V, 5.1 KWH SA Lithium, we usually discharge the battery from fully charged  at about 16:00 to 48 V at about 23:00, by then my system switches over to mains and keeps the battery at that level using a bit of power from mains.

OEM recommends max charging current  50 Amps, I do it at 20 Amps, not in a rush to charge the battery.

See screen shot of the last 24 hours.

I'm I doing something wrong ? please your expert advise will be highly appreciated.

 

 

Edited November 3, 20214 yr by Antonio de Sa
to add more info.

1 hour ago, 87 Dream said:

Hi Antonio, 

There are probably 3 ways in which we can reduce the amount of cycles on this LiFePo4 chemistry.

1) high charge & discharge rates (high C values) You already have this covered in your post above...

2) keeping a high SoC charge & staying at these values for too long

3) Keeping low state of charge for too long

I will post my favourite LiFePO4 SoC to voltage curve here again, apologies for the repetition of this curve but it is the fundamental basis to which understanding is made in this chemistry. Stay away from the steep parts of the curve....high & low SoC. The amber & Red zones. Stress is taking place in these zones. 

Remember: this curve is based on a single 3.2V nominal cell. Your pack is 16s (series) so all of our calculations need division by 16 for the curve to make sense. Your pack also says 51.2V which is the main clue it's 16s because 51.2V ÷ 16 = 3.2V nominal. 

Let's forget OEM numbers stated in the recommendations. What is a good bulk & float voltage (peak voltage for charge) I would say each cell at 3.43V at most X 16s = 55V (Bulk & float) 

Lowest Voltage discharge number. I would say 3.1V at most X 16s = 49.6V (back to grid voltage) & even battery cutoff shutdown voltage at 49V. 

I recommend the above, because have a look at how much ah on your stats on the Growatt monitoring system you will get out of this Voltage shift of 55V - 49.6V. Will be around close to 85% depth of discharge. The other 15% that is left is where the stress occurs & this is where you eat up cycle life later on.

You will see that for the squeeze of the last 15% left in the battery there is not much value to do this. You must also accept that you will not fully charge to 100% at these numbers & accept that up to 92% is still a very healthy number to charge up to. 

Once every month though as a maintenance function, I suggest you take the batteries to a high 100% SoC to top balance so to 56V bulk & float. This will ensure a top balance of your cells are carried out by the BMS every calendar month. 

You are not doing anything wrong here in your data, especially the lower rates of charge at 20A very good practice. 

To clarify why a maintenance top balance is done every month is because no two cells are made exactly the same from the factory. The manufacturing process involves human variables & so it's impossible for all 16 cells to have the same internal resistance up to the last decimal. Your daily charge & discharge cycle will make some cells drift. However, every month taking them up to a high SoC the BMS will balance the voltages & in so doing top up the low cells from the high cells. It becomes a robin hood. Steals from the rich to pay the poor. This practise will ensure a well matched 16 cells for the life span of the cycle life of this battery. I guarantee you: If used this way will have more than 80% capacity left over after 6000 cycles.

I probably gave you too much information here @Antonio de Sa☺️ but I wanted to drive the understanding of the chemistry & why we do what we do. 

87

 

 

 

1 hour ago, 87 Dream said:

Hi Antonio, 

There are probably 3 ways in which we can reduce the amount of cycles on this LiFePo4 chemistry.

1) high charge & discharge rates (high C values) You already have this covered in your post above...

2) keeping a high SoC charge & staying at these values for too long

3) Keeping low state of charge for too long

I will post my favourite LiFePO4 SoC to voltage curve here again, apologies for the repetition of this curve but it is the fundamental basis to which understanding is made in this chemistry. Stay away from the steep parts of the curve....high & low SoC. The amber & Red zones. Stress is taking place in these zones. 

Remember: this curve is based on a single 3.2V nominal cell. Your pack is 16s (series) so all of our calculations need division by 16 for the curve to make sense. Your pack also says 51.2V which is the main clue it's 16s because 51.2V ÷ 16 = 3.2V nominal. 

Let's forget OEM numbers stated in the recommendations. What is a good bulk & float voltage (peak voltage for charge) I would say each cell at 3.43V at most X 16s = 55V (Bulk & float) 

Lowest Voltage discharge number. I would say 3.1V at most X 16s = 49.6V (back to grid voltage) & even battery cutoff shutdown voltage at 49V. 

I recommend the above, because have a look at how much ah on your stats on the Growatt monitoring system you will get out of this Voltage shift of 55V - 49.6V. Will be around close to 85% depth of discharge. The other 15% that is left is where the stress occurs & this is where you eat up cycle life later on.

You will see that for the squeeze of the last 15% left in the battery there is not much value to do this. You must also accept that you will not fully charge to 100% at these numbers & accept that up to 92% is still a very healthy number to charge up to. 

Once every month though as a maintenance function, I suggest you take the batteries to a high 100% SoC to top balance so to 56V bulk & float. This will ensure a top balance of your cells are carried out by the BMS every calendar month. 

You are not doing anything wrong here in your data, especially the lower rates of charge at 20A very good practice. 

To clarify why a maintenance top balance is done every month is because no two cells are made exactly the same from the factory. The manufacturing process involves human variables & so it's impossible for all 16 cells to have the same internal resistance up to the last decimal. Your daily charge & discharge cycle will make some cells drift. However, every month taking them up to a high SoC the BMS will balance the voltages & in so doing top up the low cells from the high cells. It becomes a robin hood. Steals from the rich to pay the poor. This practise will ensure a well matched 16 cells for the life span of the cycle life of this battery. I guarantee you: If used this way will have more than 80% capacity left over after 6000 cycles.

I probably gave you too much information here @Antonio de Sa☺️ but I wanted to drive the understanding of the chemistry & why we do what we do. 

87

 

 

@87 Dream Thank you very much for the explanation, really appreciated, I've changed the setting on my inverters, I will keep an eye on the results. will give you feed back

soon. I'm not running the system on a BMS that is why I monitor the results on my monitoring system ( designed by my son ) and that way I can see all the parameters that really matter. I will follow your recommendation of once a month taking the battery to full voltage charge.

 

11 hours ago, 87 Dream said:

Cooler I think will bring forth better results. But it's probably unproven just an opinion. 

They don't provide more data on different temps because Lab time costs money

 

17 hours ago, branderplank said:

So what is the ideal temp? All the charts usually show battery levels at 25 degree C.

From Pylon documentation:

So, the Pylons are clearly optimised for 25C, but in practice 20-30 range is good.

 

30 minutes ago, 87 Dream said:

 

@87 Dream

@Antonio de Sahow are you running these without a BMS?

Yes, without BMS, if I connect the BMS  overrides the setting on the Growatt inverters and charges at 50 Amps, I don't want that

Did you build the pack yourself using individual cells or is it the 5.1kWh prebuild pack as supplied by LBSA?

The battery is a standard LBSA 5.1 KWh battery

Great that your son has these skills. These are the skills we need in this Solar Game. Because these battery manufacturers unfortunately make a system sell it us then change that system & then revoke support for that system leaving us at a Dead end. You cant upgrade without spending & then your last product is not compatible. 

Struggle a bit to get the PI  to connect to the battery but eventually we got it working.

With my monitoring system I can retrieve and display every single parameter, both from the inverter as well as the battery, this information is archived in our home server in case there are future guaranty claim issues 

If we get more understanding, access to cells & ppl that can integrate systems we become more self reliant & independent of a big name. 

That would be the ideal world, but one has to accept that lots of money goes in R&D and we unfortunately pay for it, including the clones that spent nothing and push they products down our throats 

Screen shot of my daily consumption/production, my system it's new just about a month old

 

87

 

 

Edited November 3, 20214 yr by Antonio de Sa
to add more info.

Speaking of DOD, today I went and bought my second Pylontech us3000c (im going to electrocute myself tonight) I use BMS and set option 21 on the Growatt inverter to switch back to utility at 20% battery capacity.  The guy at the Solar place said the Pylontechs have a 95% DOD and recommended I lower it to maybe 10% to get more out of each battery cycle, but i would like to check if your guys opinions differ on this.

What do you guys think?

@hoohloc what do you set your max discharge in percentage for your Pylons?

Ps any advice on hooking up my second battery would be appreciated, any things i should be careful of, issues with BMS etc

@Antonio de Sa since you hijacked my thread 😛 help a noob out, how are you getting that graph information? Is that in the server.growatt website app or is it a seperate BMS login specific to your battery. Not sure If my pylons have some type of BMS login or if I should maybe just not touch it because I dono what I'm doing

19 minutes ago, roadkill said:

Ps any advice on hooking up my second battery would be appreciated, any things i should be careful of, issues with BMS etc

I can't remember how to set the address of the US3000c, but one needs to be a master. Hook them up with the supplied links, set the dipswitches of Master to 1000 and slave to 0000. if that doesn't work, change the master dipswitch to 0001 while leaving the slave at 0000. If this doesn't work, invert the settings

try 0111 for master and 1111 for slave 

^^ I dont think you have to mess with the dip switches at all ? when i added my second 3000C the manual said to just make sure the link port 0 is open on the master and connect CAN of master to inverter. @roadkill I do 90% DOD daily . Everything works great.

Edited November 4, 20214 yr by Nexuss

I have a 80% DoD battery and it better that SLA'S I had but that extra 15% is over 1kwh for me that I can't use.