zeestone99:


It looks like it has inbuilt BMS. Oga juo can give you more details

please check details above

saint2ace:


It looks like a carefully put together bank with breakers and all. I should presume it's plug and play but let's wait for @JUO to throw more light...

please check if I have answered your question above

earthrealm:


I feel you may have some bad/weak batteries in the mix, i suggest you buy or borrow a 12v battery load tester and check each battery 1 by 1.

Charging very fast is a classic sign of bad battery, how old is your battery?.
When did you introduce solar?. Hope from day 1, cos that inverter looks like a dumb inverter, not capable of charging fla batts.

Lastly, hope your cc is configured properly to charge flooded battery, what are your absorb and float voltage settings

Thank you very much for the response.

I reached out to the OEM (MUST) through their customer support. They asked me for my solar panel array and capacity of the panels ; they also asked me to note the battery voltages displayed by the CC every 30 mins (or less) from sun rise to sunset and record them along with the PV . I did so yesterday (tiring though) and sent to them. They responded last night that from the data provided, the CC is working perfectly and that the data shows that my CC is doing approximately 2 - 2.5 hrs of bulk charge , 6 hrs of absorption and 2 hrs of float. I have told them the indicator light is blinking contrary to what is meant for absorption as it blinks at a rate meant for floating during the absorption period (they are yet to respond). The inverter is the transformer type and has settings for flooded batteries (however, I am offgrid so no charging from the inverter).
Additionally, they said it is highly unlikely i have weak batteries because the timelines and battery voltages for both banks are similar when charging.
Nevertheless,a technician will come do a load test today although the batteries are very new (less than a month)

danowena:


Thank you very much for the response.

I reached out to the OEM (MUST) through their customer support. They asked me for my solar panel array and capacity of the panels ; they also asked me to note the battery voltages displayed by the CC every 30 mins (or less) from sun rise to sunset and record them along with the PV . I did so yesterday (tiring though) and sent to them. They responded last night that from the data provided, the CC is working perfectly and that the data shows that my CC is doing approximately 2 - 2.5 hrs of bulk charge , 6 hrs of absorption and 2 hrs of float. I have told them the indicator light is blinking contrary to what is meant for absorption as it blinks at a rate meant for floating during the absorption period (they are yet to respond). The inverter is the transformer type and has settings for flooded batteries (however, I am offgrid so no charging from the inverter).
Additionally, they said it is highly unlikely i have weak batteries because the timelines and battery voltages for both banks are similar when charging.
Nevertheless,a technician will come do a load test today although the batteries are very new (less than a month)

look for the failing battery and replace you should be fine

JUO:
please check if I have answered your question above

U're doing well..

JUO:
look for the failing battery and replace you should be fine

Thanks for lending your voice to this.
Load test and hygrometer reading done today showed that all batteries are okay.

danowena:
Thanks for lending your voice to this.
Load test and hygrometer reading done today showed that all batteries are okay.

Ok, good news for you, since the batts are barely 2 months old, the odds of them being bad are slim, however fast charging is usually caused by weak battery in the mix.

Since you have ruled that out, what is your avg daily harvest f
As shown on the CC?. And avg instant charging current on CC.
Total cummulative harvest by the 3hrs that the battery enters float

Edit, how was the load test done?? , people can be cunny&funny atimes
Did you witness the load test, was a standard load tester used?

ojeysky:
Anyone interested in this 12v 280AH bundle package should reach out to me:

Here is what you get:
- 4x280AH cells
- Adjustable 2-40A, 11-16v lithium charger
- 35A smart BMS with Bluetooth monitoring
- Connection bus bars (3 pieces)
- 4s balancer

Price 350k

Fwiw, it's some of the cells that I use personally and I have not confirmed actual capacity.

WhatsApp 0 8 zero three five 2 3 3535

Still available and negotiable; removing some accessories will reduce the price

Sharp Stoba EA-BA1000

Premium Lithium Battery at the price of AGM/GEL/Flooded

1Kwh, 48.1v nominal, 20.6Ah Lithium Ion Battery with Sharp Stoba addictive

Extended Cycle life. Increase Capacity. Enhance Safety. Reduce Cost. High Quality BMS inbuilt

Experience Lithium technology without breaking the bank

N135,000.00

Contact: 080 five five 35 six 495

dapsyra:
Sharp Stoba EA-BA1000

Premium Lithium Battery at the price of AGM/GEL/Flooded

1Kwh, 48.1v nominal, 20.6Ah Lithium Ion Battery with Sharp Stoba addictive

Extended Cycle life. Increase Capacity. Enhance Safety. Reduce Cost. High Quality BMS inbuilt

Experience Lithium technology without breaking the bank

N135,000.00

Contact: 080 five five 35 six 495

Buyers' beware. Not a regular lithium setup. Clearly not for anyone starting a lithium journey. Looks like a custom setup made for a japanese robot. Look very well before you take the plunge.
https://jspower.en.taiwantrade.com/product/battery-for-assist-robot-670510.html#
https://forum.esk8.news/t/battery-clearing-house-sv-ba10-13s-20ah-battery/22100/249

Yea, it is not a regular Chinese knock-off. It is premium quality; good enough to power Japanese Robots. It is normal practice to repurpose Lithium batteries for uses other than the original design especially when the battery is of very good quality.

What is important is the quality, durability and safety of the battery. The Sharp Stobe battery is of premium quality having been originally made to power robots. It is very durable with extended cycle life and also delivers the rated power. The chemistry is also very safe since it does not burst into flames when abused.

Since the specifications, quality, longevity and safety exceeds those of many other Lithium batteries in use today, there is therefore nothing for buyer's to beware of.

adrusa:


Buyers' beware. Not a regular lithium setup. Clearly not for anyone starting a lithium journey. Looks like a custom setup made for a japanese robot. Look very well before you take the plunge.
https://jspower.en.taiwantrade.com/product/battery-for-assist-robot-670510.html#
https://forum.esk8.news/t/battery-clearing-house-sv-ba10-13s-20ah-battery/22100/249

dapsyra:
Sharp Stoba EA-BA1000

Premium Lithium Battery at the price of AGM/GEL/Flooded

1Kwh, 48.1v nominal, 20.6Ah Lithium Ion Battery with Sharp Stoba addictive

Extended Cycle life. Increase Capacity. Enhance Safety. Reduce Cost. High Quality BMS inbuilt

Experience Lithium technology without breaking the bank

N135,000.00

Contact: 080 five five 35 six 495

Is the battery brand new or used?

mctfopt:


Is the battery brand new or used?

It is brand new in mint condition

earthrealm:


This article is a good read, and tackles all aspects of the lifepo4 vs lead acid debate..
I must warn you, its a long read ..

Peeps averse to long reads can scroll to midway and read only the pros and cons of Lifepo4 battery bank.

https://marinehowto.com/lifepo4-batteries-on-boats/

tanx for the link bro. i've spent quite some time purring over the contents and its really interesting.
this rod guy leaves nothing to the imagination and seems to bare it all. the quote below was lifted
directly from the site and if this doesn't mean anything to anyone then nothing else will:

"WARNING / DIY BUILDS:

I do not believe LiFePO4 is ready for mass DIY prime time builds. Read with caution,
and especially focus on the things that you don’t want to hear rather than only what you want to hear.
Once you are done reading this, and it makes sense to you, then please spend another few months reading
everything you can including every single LiFePO4 white paper you can get your hands on.

While this article is meant to be very basic, and get you a basic level of understanding of LFP,
the science side of it matters too. We strongly recommend that you also read Eric Bretscher’s site for
the science side of LFP:

Nordkyn Design LiFePO4

With this article, and Eric’s information, you’ll be well on your way to understanding how to use a LiFePo4
marine system without ruining it prematurely.

Wallet Burns:
Since opening this article to the public we have now had what I consider a rather high number of LiFePO4
owners contact us who’ve ruined LiFePo4 batteries (not all marine based). In almost all of these cases of
destroyed LiFePO4 batteries the resounding tone I hear come through is;

“But Rod, People on the internet made it sound so easy?“

Hey, lets face it, everyone gets excited with their new toys, and likes to talk about them, but we urge
you to please do more research. In other-words, don’t jump to conclusions based on scant information, where
large sums of money are involved."

dapsyra:


It is brand new in mint condition

Thank you

ojesymsym:
Looks like the sun's trajectory across the sky has shifted a bit by a few mini degrees.

yup...i now get some better sunlight hours from my shaded panels than previous months. ... i now know when to expect good sunlight and poor sunlight.

I can speak to the complexity of Lithium vs lead acid.

There is so much one needs to get right else a huge investment would go down the drain.

I use a popular and well reviewed battery - PylonTech. You are told you can add new batteries to the bank at will. In reality it is not so straight.

I got my first set of 8 in November 2019 and it was easy peasy until I added the 2nd set of 8 in June 2020. The bottom most battery refused to catch up with the others in charge and discharge and kept throwing over voltage and over temperature alarms. I would have lost that battery had I not gained admin access to the BMS and recalibrated values to allow the module recover and catchup with the others. The cells in that module were not perfectly matched as the others and kept drifting.

Now I added 4 new bricks this October and the BMS software version is higher than the old bricks - the result - combined BMS throttled my maximum charge current to about 300A - 15kw instead of the design 500A/26kw. I am now current limited to 15kw by the battery even though I have a 20kw PV array. I have yet to figure that one out as the BMS tells the Victron chargers what to do per time and if you insert a new value, it just gets overwritten 30 seconds or so later.

The next big myth is discharge rates - you will be told you can run at 1C with no issues - this is true but only within a SoC range e.g 20% to 100% - once you drain battery below 20%, you may find the BMS cutting large loads to protect the circuitry and cells - ditto for charge rates - try filling a 48v 1000Ah battery at 1C and you see cell temperatures jump up fast - this is not good for long term health so in my case I capped my charge current at 0.3C - getting from 20% to 100% within 3 hours on a 48v 1000Ah bank is good enough performance for me.

Really there are many things to consider and get right especially for large systems. I routinely see my BMV 500A shunt running hot when passing like 18kw of energy. I see up to 50degC on shunt and 40degC on bus bars so I am in the market now for 1000A shunt and even thicker bars than I already have. Even my 600A continuous rated Blue Sea Systems DC isolator runs hot when passing 18kw of energy. With the energy density of Lithium, a short or failure in the system could be catastrophic indeed.

On the plus side you get early warning of issues especially if the BMS talks to you. This is one strong advantage over lead acid. Because I can see every detail about every cell with the Texas instruments chip BMS bundled with the Pylons, you can take early corrective action. Again this info is not available plain text, a solid knowledge of cable pinouts, serial/RS485/CANBUS communications and many other esoteric skills are needed to interact with the BMS and adjust operating parameters if required

GeorgeD1:


tanx for the link bro. i've spent quite some time purring over the contents and its really interesting.
this rod guy leaves nothing to the imagination and seems to bare it all. the quote below was lifted
directly from the site and if this doesn't mean anything to anyone then nothing else will:

"WARNING / DIY BUILDS:

I do not believe LiFePO4 is ready for mass DIY prime time builds. Read with caution,
and especially focus on the things that you don’t want to hear rather than only what you want to hear.
Once you are done reading this, and it makes sense to you, then please spend another few months reading
everything you can including every single LiFePO4 white paper you can get your hands on.

While this article is meant to be very basic, and get you a basic level of understanding of LFP,
the science side of it matters too. We strongly recommend that you also read Eric Bretscher’s site for
the science side of LFP:

Nordkyn Design LiFePO4

With this article, and Eric’s information, you’ll be well on your way to understanding how to use a LiFePo4
marine system without ruining it prematurely.

Wallet Burns:
Since opening this article to the public we have now had what I consider a rather high number of LiFePO4
owners contact us who’ve ruined LiFePo4 batteries (not all marine based). In almost all of these cases of
destroyed LiFePO4 batteries the resounding tone I hear come through is;

“But Rod, People on the internet made it sound so easy?“

Hey, lets face it, everyone gets excited with their new toys, and likes to talk about them, but we urge
you to please do more research. In other-words, don’t jump to conclusions based on scant information, where
large sums of money are involved."

NiyiOmoIyunade:
I can speak to the complexity of Lithium vs lead acid.

There is so much one needs to get right else a huge investment would go down the drain.

I use a popular and well reviewed battery - PylonTech. You are told you can add new batteries to the bank at will. In reality it is not so straight.

I got my first set of 8 in November 2019 and it was easy peasy until I added the 2nd set of 8 in June 2020. The bottom most battery refused to catch up with the others in charge and discharge and kept throwing over voltage and over temperature alarms. I would have lost that battery had I not gained admin access to the BMS and recalibrated values to allow the module recover and catchup with the others. The cells in that module were not perfectly matched as the others and kept drifting.

Now I added 4 new bricks this October and the BMS software version is higher than the old bricks - the result - combined BMS throttled my maximum charge current to about 300A - 15kw instead of the design 500A/26kw. I am now current limited to 15kw by the battery even though I have a 20kw PV array. I have yet to figure that one out as the BMS tells the Victron chargers what to do per time and if you insert a new value, it just gets overwritten 30 seconds or so later.

The next big myth is discharge rates - you will be told you can run at 1C with no issues - this is true but only within a SoC range e.g 20% to 100% - once you drain battery below 20%, you may find the BMS cutting large loads to protect the circuitry and cells - ditto for charge rates - try filling a 48v 1000Ah battery at 1C and you see cell temperatures jump up fast - this is not good for long term health so in my case I capped my charge current at 0.3C - getting from 20% to 100% within 3 hours on a 48v 1000Ah bank is good enough performance for me.

Really there are many things to consider and get right especially for large systems. I routinely see my BMV 500A shunt running hot when passing like 18kw of energy. I see up to 50degC on shunt and 40degC on bus bars so I am in the market now for 1000A shunt and even thicker bars than I already have. Even my 600A continuous rated Blue Sea Systems DC isolator runs hot when passing 18kw of energy. With the energy density of Lithium, a short or failure in the system could be catastrophic indeed.

On the plus side you get early warning of issues especially if the BMS talks to you. This is one strong advantage over lead acid. Because I can see every detail about every cell with the Texas instruments chip BMS bundled with the Pylons, you can take early corrective action. Again this info is not available plain text, a solid knowledge of cable pinouts, serial/RS485/CANBUS communications and many other esoteric skills are needed to interact with the BMS and adjust operating parameters if required

Good to hear your experience with PylonTech. However, PylonTech is not "lithium battery", it is a battery system based on lithium chemistry. If you need "esoteric skills" to get information out of your proprietary battery system as you suggested for your PylonTech, that is PylonTech problem, not a lithium battery problem and the manufacturer has failed. I have made a mental note of avoiding PylonTech if it is as bad and as complex as you suggested. I suggest you rip out the PylonTech BMS and replace it with something you will have absolute control over. That is what I did for my Felicity lithium; I replaced its BMS with ANT BMS.

Felicity lithium battery is devoid of all that complexity. DIY lithium batteries when properly done are even simpler. The esoteric skills you need to talk to your batteries using some popular BMSes are pairing your phone to a bluetooth device or connecting a usb cable to your computer and running an application.

adrusa:


Good to hear your experience with PylonTech. However, PylonTech is not "lithium battery", it is a battery system based on lithium chemistry. If you need "esoteric skills" to get information out of your proprietary battery system as you suggested for your PylonTech, that is PylonTech problem, not a lithium battery problem and the manufacturer has failed. I have made a mental note of avoiding PylonTech if it is as bad and as complex as you suggested. I suggest you rip out the PylonTech BMS and replace it with something you will have absolute control over. That is what I did for my Felicity lithium; I replaced its BMS with ANT BMS.

The thing is that pylontech BMS has incorporated quite some interesting restrictions, perhaps for their 10 to 15 years life expectation to be guaranteed hence they don't charge more than 3.4+v and low max charge current as well. As you've rightly said, the problem is not the battery but the BMS. A typical lithium will do 1C comfortably without issues, though my system is not designed for 1C(560A) else would have personally tried it out, some chemistries even do more than that. The heat however can be as a result of other factors such as cell connection terminals, cell imbalance, the BMS hitting it's peak, charging source cables etc

Felicity lithium battery is devoid of all that complexity. DIY lithium batteries when properly done are even simpler. The esoteric skills you need to talk to your batteries using some popular BMSes are pairing your phone to a bluetooth device or connecting a usb cable to your computer and running an application.

For DIY users like myself, using a manageable BMS makes Lifepo4 to be so much fun, one of my cell voltage was rising some time ago and I checked the cells to realise it was due to a not well connected cell terminal. I have a relatively balanced cell now

adrusa:


Good to hear your experience with PylonTech. However, PylonTech is not "lithium battery", it is a battery system based on lithium chemistry. If you need "esoteric skills" to get information out of your proprietary battery system as you suggested for your PylonTech, that is PylonTech problem, not a lithium battery problem and the manufacturer has failed. I have made a mental note of avoiding PylonTech if it is as bad and as complex as you suggested. I suggest you rip out the PylonTech BMS and replace it with something you will have absolute control over. That is what I did for my Felicity lithium; I replaced its BMS with ANT BMS.

Felicity lithium battery is devoid of all that complexity. DIY lithium batteries when properly done are even simpler. The esoteric skills you need to talk to your batteries using some popular BMSes are pairing your phone to a bluetooth device or connecting a usb cable to your computer and running an application.

Or maybe it is a problem of being too techy and demanding. Most people will use their devices as the manufacturers intended. They will buy a TV, scan channels, connect their DSTV decoder and spend the next 10 years only changing channels and increasing and reducing volume. People like you and me will look for remote codes to add functions to our TV, root it, SSH into it and generally mess around with it. A normal person will probably buy the PylonTech battery, get it installed and spend the next 10 years only checking the led to assess state of charge. No serial or RS485 or connecting to any terminal or computer.

Technophiles make everything look complicated. When I buy an android phone, I install a custom recovery, root it and then start searching the fora for custom ROMs. When I'm tired of monkeying with it, I return it to stock before I hand it over to my wife who enjoys the phone without bothering about rooting or custom ROMs.

Boss you are suggesting I open up a factory sealed product with 7 year warranty and replace the industrial grade BMS inside with a version preferred by DIYers

You need esoteric skills to 'roll your own' - remember the BMS is the one triggering alarms and all? It is designed to take care of all fault conditions - balancing a heavily mismatched pack may take weeks to accomplish if the BMS was left alone - I simply edited parameters to help things along and got everything done in 3 days or so.

More importantly, PylonTech integration with Victron needs the propietary Pylon BMS and no other. The Pylon BMS was intended to provide detailed product info but not for the end user to perform admin functions through - even their batteryview software is mostly hidden behind the great chinese firewall - if you wish to perform admin functions on the battery, then you must be ready to jump through hoops.

adrusa:


Good to hear your experience with PylonTech. However, PylonTech is not "lithium battery", it is a battery system based on lithium chemistry. If you need "esoteric skills" to get information out of your proprietary battery system as you suggested for your PylonTech, that is PylonTech problem, not a lithium battery problem and the manufacturer has failed. I have made a mental note of avoiding PylonTech if it is as bad and as complex as you suggested. I suggest you rip out the PylonTech BMS and replace it with something you will have absolute control over. That is what I did for my Felicity lithium; I replaced its BMS with ANT BMS.

Felicity lithium battery is devoid of all that complexity. DIY lithium batteries when properly done are even simpler. The esoteric skills you need to talk to your batteries using some popular BMSes are pairing your phone to a bluetooth device or connecting a usb cable to your computer and running an application.

The more I look into the Pylon BMS workings, the more I am convinced that the manufacturer knows their battery.

The charge and discharge current logic are hardcoded in the BMS such that as the battery fills up it automatically throttles charge current and as you drain the battery towards 80% and beyond it begins to throttle discharge current too - this is inspite of the advertised spec sheet.

They guarantee 6,000 cycles at 80% DoD and with 80% capacity left after those 6,000 cycles. In fact they imply that the electronics and control mechanisms would fail well before the actual battery cells fail.

My batteries sit in a temperature controlled room set for 25°C - while charging at up to 0.5C I can see cell temperatures get to 30°C or slightly higher - charging at 0.3C the temperature sits at 28°C max. The battery is certified for -10°C to 50°C or thereabouts - I needed no soothsayer to tell me to use the lower charge rate that kept the batteries cooler.

When I complained about one module falling behind, we were yet to install AC in the power room - the troubled module reached 35°C when others were still at 32°C or so - all well within the operating range but for the USD expended for acquisition I was not ready to take any risks.

Most folks would use their batteries at factory defaults happily unaware of the goings on in the battery and this would suffice.

See me now trying to force the BMS to request 500A from Victron inverter and MPPTs meanwhile I had set my max current limit in the Victron GX device at 350A. I just want to have the battery run at full throttle even if I will slow down later. Now sue me

PS: The actual recommended charge voltage range is between 52.5v and 53.2v - there are 15 cells in series per module so 3.5 to 3.55v per cell. The BMS will cut out for overvoltage at 54v so very little headroom for errors or spikes - with this you see how paranoid the BMS is. Battery top balancing will start once any cell reaches about 3.48v

I use 52.5v as charge voltage and plan to go back down to 52v just as soon as the new modules settle in fully. The goal is to cycle between 25% and 98% on a regular basis

ojeysky:


The thing is that pylontech BMS has incorporated quite some interesting restrictions, perhaps for their 10 to 15 years life expectation to be guaranteed hence they don't charge more than 3.4+v and low max charge current as well. As you've rightly said, the problem is not the battery but the BMS. A typical lithium will do 1C comfortably without issues, though my system is not designed for 1C(560A) else would have personally tried it out, some chemistries even do more than that. The heat however can be as a result of other factors such as cell connection terminals, cell imbalance, the BMS hitting it's peak, charging source cables etc



For DIY users like myself, using a manageable BMS makes Lifepo4 to be so much fun, one of my cell voltage was rising some time ago and I checked the cells to realise it was due to a not well connected cell terminal. I have a relatively balanced cell now

NiyiOmoIyunade:
The more I look into the Pylon BMS workings, the more I am convinced that the manufacturer knows their battery.

The charge and discharge current logic are hardcoded in the BMS such that as the battery fills up it automatically throttles charge current and as you drain the battery towards 80% and beyond it begins to throttle discharge current too - this is inspite of the advertised spec sheet.

The above is normal behaviour, at least for my DIY as well, though I have not observed the trottling below 80% I think your BMS is doing that not because of the components but to allow for close discharge of the cells as the curve is very steep (runs faster) once the capacity is below 80%

They guarantee 6,000 cycles at 80% DoD and with 80% capacity left after those 6,000 cycles. In fact they imply that the electronics and control mechanisms would fail well before the actual battery cells fail.

Yeah 80% is normal capacity left in most lithium batteries after completing their initial cycles, it's actually not unique to plyontech, what I think is unique is the controlled charge and discharge which makes sense to protect the components while for DIY one can just change components at some points in the lifespan of the battery bank.

My batteries sit in a temperature controlled room set for 25°C - while charging at up to 0.5C I can see cell temperatures get to 30°C or slightly higher - charging at 0.3C the temperature sits at 28°C max. The battery is certified for -10°C to 50°C or thereabouts - I needed no soothsayer to tell me to use the lower charge rate that kept the batteries cooler.

Yeah this is typical and I do observe it as well but I think the increasing temperature is due to the connecting terminals, when I place my battery temp sensors on the sides of the cells, the temperature is much lower than that of the connecting terminals so I think the components of connecting the cells is very critical. I personally also prefer to charge at 0.5C max but I don't think those that have small banks will have much leverage especially if they have a BMS that can support it. Someone who has a single pylontech 2000 will be limited to 25A but if I have a 50AH DIY one will be tempted to do above 0.5C often so the sun rays can be maximised

When I complained about one module falling behind, we were yet to install AC in the power room - the troubled module reached 35°C when others were still at 32°C or so - all well within the operating range but for the USD expended for acquisition I was not ready to take any risks.

Most folks would use their batteries at factory defaults happily unaware of the goings on in the battery and this would suffice.

See me now trying to force the BMS to request 500A from Victron inverter and MPPTs meanwhile I had set my max current limit in the Victron GX device at 350A. I just want to have the battery run at full throttle even if I will slow down later. Now sue me

PS: The actual recommended charge voltage range is between 52.5v and 53.2v - there are 15 cells in series per module so 3.5 to 3.55v per cell. The BMS will cut out for overvoltage at 54v so very little headroom for errors or spikes - with this you see how paranoid the BMS is. Battery top balancing will start once any cell reaches about 3.48v

I use 52.5v as charge voltage and plan to go back down to 52v just as soon as the new modules settle in fully. The goal is to cycle between 25% and 98% on a regular basis

You have a monster bank my brother, I do envy you just that there will be deficit of organs if I was to go your route

That said, I really think oversizing battery banks is the best thing to do, I am 25 days into using my current cells and I have only done 2 cycles. I can't imagine how many years this thing will last me if I don't break the system due to my curiosity

Boss I hail,
I'm quite impress with your tech savvy levels, and I have always taken pylontech words of adding battery along the line with a pinch of salt, but glad you detailed it all out.

NiyiOmoIyunade:
The more I look into the Pylon BMS workings, the more I am convinced that the manufacturer knows their battery.

The charge and discharge current logic are hardcoded in the BMS such that as the battery fills up it automatically throttles charge current and as you drain the battery towards 80% and beyond it begins to throttle discharge current too - this is inspite of the advertised spec sheet.

They guarantee 6,000 cycles at 80% DoD and with 80% capacity left after those 6,000 cycles. In fact they imply that the electronics and control mechanisms would fail well before the actual battery cells fail.

My batteries sit in a temperature controlled room set for 25°C - while charging at up to 0.5C I can see cell temperatures get to 30°C or slightly higher - charging at 0.3C the temperature sits at 28°C max. The battery is certified for -10°C to 50°C or thereabouts - I needed no soothsayer to tell me to use the lower charge rate that kept the batteries cooler.

When I complained about one module falling behind, we were yet to install AC in the power room - the troubled module reached 35°C when others were still at 32°C or so - all well within the operating range but for the USD expended for acquisition I was not ready to take any risks.

Most folks would use their batteries at factory defaults happily unaware of the goings on in the battery and this would suffice.

See me now trying to force the BMS to request 500A from Victron inverter and MPPTs meanwhile I had set my max current limit in the Victron GX device at 350A. I just want to have the battery run at full throttle even if I will slow down later. Now sue me

PS: The actual recommended charge voltage range is between 52.5v and 53.2v - there are 15 cells in series per module so 3.5 to 3.55v per cell. The BMS will cut out for overvoltage at 54v so very little headroom for errors or spikes - with this you see how paranoid the BMS is. Battery top balancing will start once any cell reaches about 3.48v

I use 52.5v as charge voltage and plan to go back down to 52v just as soon as the new modules settle in fully. The goal is to cycle between 25% and 98% on a regular basis

It seems we always misunderstand each other's meaning or intentions. Much like the 3 phases of an electrical system are 120° out of phase with each other

I will say no more on this topic.

As regards affording a large battery bank, there is a technique to it where you won't have to donate too many critical organs, one option is to spread the burden/crowdsource your acquisitions and you are already on that path as you retail RE gadgets and tools. Build enough velocity behind that and it becomes easier to take one or two batteries or other gadgets for personal use without feeling the impact too much

Also good deals come up if you keep your nose in the business - one of my pioneer Pylontech customers is relocating, I have been praying hard that he leaves soon so that I can take over his 4 PylonTech batteries and Victron 5kva Multiplus at a good price

Win win for everybody.

ojeysky:


The above is normal behaviour, at least for my DIY as well, though I have not observed the trottling below 80% I think your BMS is doing that not because of the components but to allow for close discharge of the cells as the curve is very steep (runs faster) once the capacity is below 80%



Yeah 80% is normal capacity left in most lithium batteries after completing their initial cycles, it's actually not unique to plyontech, what I think is unique is the controlled charge and discharge which makes sense to protect the components while for DIY one can just change components at some points in the lifespan of the battery bank.



Yeah this is typical and I do observe it as well but I think the increasing temperature is due to the connecting terminals, when I place my battery temp sensors on the sides of the cells, the temperature is much lower than that of the connecting terminals so I think the components of connecting the cells is very critical. I personally also prefer to charge at 0.5C max but I don't think those that have small banks will have much leverage especially if they have a BMS that can support it. Someone who has a single pylontech 2000 will be limited to 25A but if I have a 50AH DIY one will be tempted to do above 0.5C often so the sun rays can be maximised



You have a monster bank my brother, I do envy you just that there will be deficit of organs if I was to go your route

That said, I really think oversizing battery banks is the best thing to do, I am 25 days into using my current cells and I have only done 2 cycles. I can't imagine how many years this thing will last me if I don't break the system due to my curiosity

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adrusa:
... That is what I did for my Felicity lithium; I replaced its BMS with ANT BMS.

Could we have insight of the inner workings or even pictures of the cells used?

NiyiOmoIyunade:
It seems we always misunderstand each other's meaning or intentions. Much like the 3 phases of an electrical system are 120° out of phase with each other

I will say no more on this topic.

As regards affording a large battery bank, there is a technique to it where you won't have to donate too many critical organs, one option is to spread the burden/crowdsource your acquisitions and you are already on that path as you retail RE gadgets and tools. Build enough velocity behind that and it becomes easier to take one or two batteries or other gadgets for personal use without feeling the impact too much

Also good deals come up if you keep your nose in the business - one of my pioneer Pylontech customers is relocating, I have been praying hard that he leaves soon so that I can take over his 4 PylonTech batteries and Victron 5kva Multiplus at a good price

Win win for everybody.

Not really actually I understood you big time, let's just say I was hailing you as the chairman and certainly there is always opportunities for awoof, especially the ones that will not run belle
I also plan on adding to my cells as the needs and corresponding funds plus the right opportunity emerge. So ultimately for me the point is that I like to start relatively big with a tight budget and that it at the cost of sacrificing other privileges that I don't consider to be redlinners. Ultimately na win win and all na lithium eventually.

Saipro:

Could we have insight of the inner workings or even pictures of the cells used?

I will see what I can do. I could have taken all those pictures the day I installed the BMS because I brought out the entire thing. As I said, it was really well built. I wish I can get a good welder or iron bender to construct such nice cage for my other DIY.

We are still entirely out of phase.....

ojeysky:


Not really actually I understood you big time, let's just say I was hailing you as the chairman and certainly there is always opportunities for awoof, especially the ones that will not run belle
I also plan on adding to my cells as the needs and corresponding funds plus the right opportunity emerge. So ultimately for me the point is that I like to start relatively big with a tight budget and that it at the cost of sacrificing other privileges that I don't consider to be redlinners. Ultimately na win win and all na lithium eventually.

adrusa:


I will see what I can do. I could have taken all those pictures the day I installed the BMS because I brought out the entire thing. As I said, it was really well built. I wish I can get a good welder or iron bender to construct such nice cage for my other DIY.

For starters, what was the actual capacity label on the cells??

NiyiOmoIyunade:
We are still entirely out of phase.....

Ok