@HendrikBigChief: Well, it was -4 last night, so Spain (especially the North) is rather cold in winter. Not as cold as the Netherlands, but, hey. 
Inside, it was still 12+ so, thats not a problem

The lowest we have gotten so far is a DOD of 34%. I have to dive into the meaning of C. I see it everywhere, but I'm not shure how it works.

The biggest consumer is our coffeemaker, wich operates with 1300 Watts. We make shure everything else is off (not the lights, but higher then 100 Watts), And we operate that only during the day, and having sun. In the evenings, we make coffee by hand.

So, Discharge wise, we try to make an effort. I do not want to go below 60% DOD, but havent even been there.



 

A got it. 1C is the discharge number. 1C at a Battery of 100AH, is 100A. So charging with 0,2 C is about 20 Amps in my Case. We charge maximum with the settings from the Pylontech BMS, and thats around 27 Amps, I think. 

2 hours ago, HendrikBigChief said:

1. Do not charge them too fast, many guides recommend 0.2C. I personally charge at 0.2C.

2. Never go below 20% SOC.

3. Multiple shallow discharges better than one deep discharge. The "damage" done is non-linear, the deeper the discharge the more severe the damage.

4. Try not to fully charge the battery, up to 90% every time seems to be the sweet spot, however, then you are losing 10% of your battery capacity. Possibly not worth it, especially with LFP cells.

5. Try not to discharge too fast as well. 0.5C seems to be good on most chemistries.

Shouldn't we just rely on the BMS? Thinking of my 200Ah Freedom Won, the charge limit and discharge limit on my inverter are both actually set by the BMS - and I can't override them. I clearly remember this. The guy installing the battery set the Goodwe inverter into "Default Lithium" mode, plugged in the BMS cable and very quickly the BMS set everything the way it wants it and that is it. If I change any of those values, they are immediately changed back. OK... so I CAN override, but only for about 1 second. 

I get that there are good ways and bad ways to treat any battery, but if I buy a battery with an integrated BMS, where everything is specified by the company whose name is on the battery, and the BMS choses to set things a certain way then that, surely, should be that and I needn't worry about over discharging or any such.

And these are the BMS settings, not a trade off between inverter and BMS. My inverter can't actually draw 140A from that battery, but that's what discharge current limit is set to.

4 hours ago, Bobster. said:

Shouldn't we just rely on the BMS? Thinking of my 200Ah Freedom Won, the charge limit and discharge limit on my inverter are both actually set by the BMS - and I can't override them. I clearly remember this. The guy installing the battery set the Goodwe inverter into "Default Lithium" mode, plugged in the BMS cable and very quickly the BMS set everything the way it wants it and that is it. If I change any of those values, they are immediately changed back. OK... so I CAN override, but only for about 1 second. 

I get that there are good ways and bad ways to treat any battery, but if I buy a battery with an integrated BMS, where everything is specified by the company whose name is on the battery, and the BMS choses to set things a certain way then that, surely, should be that and I needn't worry about over discharging or any such.

And these are the BMS settings, not a trade off between inverter and BMS. My inverter can't actually draw 140A from that battery, but that's what discharge current limit is set to.

You are right, most people will get decent battery life out of the default settings.

I am not familiar with your inverter, but on Deye and Sunsynk inverters you can set the charge and discharge rates as well as min and max SOC levels even when the BMS is connected. The BMS just sets the master max levels.

4 hours ago, Bobster. said:

Shouldn't we just rely on the BMS? Thinking of my 200Ah Freedom Won, the charge limit and discharge limit on my inverter are both actually set by the BMS - and I can't override them. I clearly remember this. The guy installing the battery set the Goodwe inverter into "Default Lithium" mode, plugged in the BMS cable and very quickly the BMS set everything the way it wants it and that is it. If I change any of those values, they are immediately changed back. OK... so I CAN override, but only for about 1 second. 

I get that there are good ways and bad ways to treat any battery, but if I buy a battery with an integrated BMS, where everything is specified by the company whose name is on the battery, and the BMS choses to set things a certain way then that, surely, should be that and I needn't worry about over discharging or any such.

And these are the BMS settings, not a trade off between inverter and BMS. My inverter can't actually draw 140A from that battery, but that's what discharge current limit is set to.

The idea seems a good one. There is one important question. If we look at some data from members with Pylontech batteries that went into over current or over voltage and these were the reasons for not honouring the claims then would you still say leave everything up to the BMS. Also we have seen how many BMSes went faulty and again a loophole was found in the T&Cs. 

2 hours ago, HendrikBigChief said:

I am not familiar with your inverter, but on Deye and Sunsynk inverters you can set the charge and discharge rates as well as min and max SOC levels even when the BMS is connected. The BMS just sets the master max levels.

Ah well... I first had Revov batteries, and with those settings on the inverter could be changed. Their BMS doesn't have comms with a Goodwe inverter. 

Freedom Won is a horse of a different feather. Plug the cable in and the BMS takes over. We might say that the tail wags the dog. 

So it's not just a simple matter of letting the BMS dictate - for me not for the battery vendor. Based on what I describe above, not all BMS are equal. 

Edited December 26, 20232 yr by Bobster.

19 hours ago, Scorp007 said:

The idea seems a good one. There is one important question. If we look at some data from members with Pylontech batteries that went into over current or over voltage and these were the reasons for not honouring the claims then would you still say leave everything up to the BMS. Also we have seen how many BMSes went faulty and again a loophole was found in the T&Cs. 

The absolute minium any BMS should do is to prevent over charging and discharging. I can set my inverter to draw 20 gazillion amps, but the BMS will at best throttle current back to a hard set limit, maybe even trip. If the BMS goes belly up then that's a big problem. 

So, got the Cable, and plugged it in. Changed the settings in Solarassistant, and behold:

On 2023/12/17 at 11:00 PM, HedgeSlammer said:

Hi Bianco,

This might be of interest to you.

It uses a 'Wemos D1 mini' (or cheap clone) and a MAX3232 module and half an old network cable (so should cost < 10 Euros), and enables the logging of data via MQTT, or in my case, influxdb.

Other than that, I see no reason why you wouldn't be able to just get a cheap USB->RS232 adaptor cable straight from the console port on the (master) pylontech to the RaspberryPi running 'Solar-Assitant'... They suggest exactly that (look for 'USB to Pylontech console' in the dropdown under 'battery' on the 'Solar-Assitant' config page). 

I don't know exactly which/how much data 'Solar-Assistant' will get from the Pylontechs, but once you've got the USB cable, you can also use it with the Pylontech 'batteryview' software to get at all the details.  I don't use SA myself, but there are others here who do.

And yes, you absolutely can use the RS232 (console) port on the Pylontech at the same time as the inverter (on the A/CAN).  Pretty sure it's the same for he RS485, but as I don't use it, I can't say 100%.

It is ordered. It will arrive here somewhere at the end of January and thenI will try it.

On 2023/12/20 at 12:53 AM, Onze Finca said:

I have a connection with an cable (crimped myself, 2 threads,) from the rs485 Bus on the masterto the LiOn port on the inverter. It communicates, the battery symbol is blinking, but I see only the totals in Solarassistant. Not Bank1 and Bank2 (As I have 2 3000C's), nor temps. I see a USB-port in Solarassistant, but it cant be selected, as there is an error: cant connect, or no such device.
Maybe a fault in the cable, but its connected, as the battery icon blinks. Its 3-5 to 8-7 on the RJ-45's, as shown in a video, from the Spanish dealer.

I assume your inverter is like mine and has wifi (mine is axpert VM III (

so I suggest using mobile app like energy mate 

then after finishing the pairing setup you can use its web portal from any computer and view data