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Posted (edited)

EDIT June 2022: Note this is an old thread with most of the comments from April. Most or all of the April comments seem to turn out to be not the solution to the problem. For the possible solution to the problem, skip to the bottom (starting at first comment after April) for more recent updates.

Sometimes all the lights flash and the battery beeps continuously. The manual says "high voltage protection", "cell voltage higher than 4V or module voltage higher than 55.5V". Happens with battery half charged not full.

Manuals says turn off for 15 mins and then back on. That works, however the issue will then happen again a day later or a week later. So far 10 times in 6 weeks.

Pylontech told me to put the float and bulk charge voltages at 52.5V, but when I asked (weeks ago, and not in relation to this issue) if "51.0V or 52.0V might be OK" for float voltage they said it would be OK as well. Should I try lower float or bulk voltage?

It also suggests in the manual as a solution "check the add switch on battery module whether is set correctly or not". The top battery has Dip 1 set to 1 and Dips 2,3 and 4 to zero. The bottom battery has them all at zero.

The bottom battery which is always the only one with the fault sometimes discharges slower and the batteries can get out of sync. For example at the moment the bottom battery has 5 green lights and the top has 4 lights (lower state of charge). EDIT June 2022: At the moment I think this was not related to the alarm and probably isn't a problem. The battery seems to have the ability to balance itself.

Any ideas?

Edited by Green Power
Posted

When this happens several days in a row I do a battery balancing and after that it stops happening for a few days or a week but then starts happening again. It suspect that the slower discharge from the bottom battery might be the cause of the problem simply because there does seem to be a correlation between when the charge levels on the two batteries appear as different and when this happens.

This morning I decided to unplug all the cables and push them back in incase this was caused by a loose connection. However when I pulled out the black cable connecting the two batteries together a piece of metal that is part of the cable stayed stuck in the battery. I couldn't get it out, so I had to use pliers, however the piece of metal is now misshapen, so that cable is now suspect/useless. However, I did have a spare cable so I was able to replace it.

I hope the cable was already damaged before I pulled it out this morning, as if so that could be the source of the problem. However, I may have damaged it just now, in which case that's not relevant. Based on this experience I think it may make sense to pull the cables out with especially great care. You have to pull with a lot of force but try to make the force directly outward and not at all diagonal. It may also make sense to avoid moving the cables in an out regularly unless you absolutely have to.

 

Posted
1 hour ago, Green Power said:

When this happens several days in a row I do a battery balancing and after that it stops happening for a few days or a week but then starts happening again. It suspect that the slower discharge from the bottom battery might be the cause of the problem simply because there does seem to be a correlation between when the charge levels on the two batteries appear as different and when this happens.

This morning I decided to unplug all the cables and push them back in incase this was caused by a loose connection. However when I pulled out the black cable connecting the two batteries together a piece of metal that is part of the cable stayed stuck in the battery. I couldn't get it out, so I had to use pliers, however the piece of metal is now misshapen, so that cable is now suspect/useless. However, I did have a spare cable so I was able to replace it.

I hope the cable was already damaged before I pulled it out this morning, as if so that could be the source of the problem. However, I may have damaged it just now, in which case that's not relevant. Based on this experience I think it may make sense to pull the cables out with especially great care. You have to pull with a lot of force but try to make the force directly outward and not at all diagonal. It may also make sense to avoid moving the cables in an out regularly unless you absolutely have to.

 

Hi, you don't really need to pull them out with a force. there is a small release button that you need to press before pulling out. If stuck, push them in while pressing that button and then pull out, they will come out easy. 

Posted

Thanks for explaining about the release button. That probably explains why I damaged one of the cables, hopefully the other ones are OK.

When the error occurs, I've been turning off both batteries even though only one is displaying the fault. That does cause a power cut for about a second once both batteries are off, but I can't see any way around this that wouldn't also cause the one second power outage.

Posted
2 hours ago, Green Power said:

Thanks for explaining about the release button. That probably explains why I damaged one of the cables, hopefully the other ones are OK.

When the error occurs, I've been turning off both batteries even though only one is displaying the fault. That does cause a power cut for about a second once both batteries are off, but I can't see any way around this that wouldn't also cause the one second power outage.

Which Pylontechs do you have? If you are using UP5000,the dip switches are up side-down but clearly labeled, so your master battery should have number 1 switch ON and all other switches OFF. The slave switched should all be on OFF position. This applies to all Pylons, doesn't matter which type. You just have to take note that they are up side down on UPS5000. If the comms cable between your two batteries is connected correctly and all power cables pushed into the terminals properly, then you might have a faulty battery. contact your supplier for warranty swap 

Pylontechs are straight forward, very basic.  

Posted

The batteries are US2000C, dip switches also upside down on this model, looks like the dip switches are correct.

The communication is connected from Link port 1 on the master battery to Link port 0 on the slave. Does that seem right?

Posted

On another forum I also posted about this and got the suggestion:

"52.5V is way too high for a float voltage.
Recommend you set:
Bulk: 51.75V
Float: 51.0V"

A post from Coulomb in January suggested to set Bulk at 52.5V and float at 51.8V although these were generic recommendations not specific to my current issue.

Here is the discussion I had with Pylontech (earlier, and not in reference to this specific issue):

PYLONTECH: "please set the following parameters that are on the battery side.........:
Bulk charge voltage 52.5V.
Float charge voltage 52.5V."

ME:"If float charging voltage of 52.5V is OK, then I guess a lower float voltage 51.0V or 52.0V might be OK for charging to less than 100%. But never >52.5V. Do you agree?"

PYLONTECH: "That's correct! Because sometimes the voltage sensors on the inverter terminals are not very accurate, the full battery voltage is around 53.2V(smaller than 54V). So 52.5V is a charge voltage value that has been limited in a safe range! You do not need to worry about this. "

Would be open to recommendations from others on float and bulk settings. e.g. @Coulomb@Beat@Donand others too.


 

Posted
17 minutes ago, Green Power said:

On another forum I also posted about this and got the suggestion:

"52.5V is way too high for a float voltage.
Recommend you set:
Bulk: 51.75V
Float: 51.0V"

A post from Coulomb in January suggested to set Bulk at 52.5V and float at 51.8V although these were generic recommendations not specific to my current issue.

Here is the discussion I had with Pylontech (earlier, and not in reference to this specific issue):

PYLONTECH: "please set the following parameters that are on the battery side.........:
Bulk charge voltage 52.5V.
Float charge voltage 52.5V."

ME:"If float charging voltage of 52.5V is OK, then I guess a lower float voltage 51.0V or 52.0V might be OK for charging to less than 100%. But never >52.5V. Do you agree?"

PYLONTECH: "That's correct! Because sometimes the voltage sensors on the inverter terminals are not very accurate, the full battery voltage is around 53.2V(smaller than 54V). So 52.5V is a charge voltage value that has been limited in a safe range! You do not need to worry about this. "

Would be open to recommendations from others on float and bulk settings. e.g. @Coulomb@Beat@Donand others too.


 

Here's my story with the 53,2 v setting.

 

Posted

Interesting that Pylontech have moderated their suggestions, although still with float = bulk. I don't own a Pylontech, so I'm just curating others' responses. I note that 52.5V for 15S (= 56.0V for 16S) is higher than the bulk voltage that I use for my home made 16S battery. My suggestion remains 52.5V bulk and 51.8V float.

Though these are higher than what I use myself (which is 55.2V bulk and 53.7V float, multiply by 15/16 for 15S). My values were chosen by Weber, who has a similar system to mine, and he knows his battery chemistry. 

Posted (edited)
8 hours ago, Coulomb said:

Interesting that Pylontech have moderated their suggestions, although still with float = bulk.

Agree.

I suppose if the battery is full ,its full.You cant really over charge a lithium if  I'm not mistaken.Just dont over-volt the battery and all should be well.

I've been running my pylontech's at 52,5v for the last week or so and they seem happy.

I think its best to monitor the batteries from their own volt readings and not just to accept what the inverter is showing.These things are not all calibrated the same.

 

Edited by Piper
Posted (edited)
18 hours ago, Green Power said:

Would be open to recommendations from others on float and bulk settings. e.g. @Coulomb@Beat@Donand others too.

Here the recommendations from Averge for my CH48100 battery packs (LFP) manufactured by Leoch:

Bulk charge 54V, float charge 51.8V.

I use the settings bulk 54V, float 51.9V. Equalization disabled. So far it works fine, these values are not very often reached and only for short time anyhow. By monitoring the BMS I noticed that it reports 100% SOC even before reaching float state and continues charging. When full some individual cells mark BL next to the voltage. I don't know what BL exactly means but I imagine it has to do with saturation.

Edited by Beat
Posted
3 hours ago, Beat said:

When full some individual cells mark BL next to the voltage. I don't know what BL exactly means but...

My guess is BL for BaLanced or BaLancing.

Posted

Thanks everyone for helping out.

The error is happening more frequently now, 4 times in last 48 hours with 3 of those since I changed to bulk charging voltage 51.8V, Floating charging voltage 51.0V.  Not sure whether to set the voltage back to the Pylontech recommended 52.5V or whether to just keep bringing the voltages lower and lower. However, guessing quite likely none of that will work. My guess is there is NOT a mismatch of several volts between the inverter and the battery because the voltage shown when discharging at low load is consistent with what you would expect for a given state of charge shown on the battery.

I think I may disconnect the one battery and run the system off one battery, at least for a while, if this keeps happening. So what I am thinking is connect the long cables to the master battery, presumably same dip position, remove short cables and other battery. Probably reduce max charging amps, other settings the same. Does that seem reasonable for just one battery?

Would it make sense to switch over the master and slave positions- I can´t think why it would work, but maybe worth a try. Or maybe I´m just getting desperate at this point.

Would it make sense to leave the faulty battery disconnected for a longer time? Several days or a week turned off rather than switching it back on after minutes or hours. Not sure if that would give voltage levels a chance to settle down and smooth out?

Pylontech suggests I buy a RJ45-DB9-USB cable to download the logs(event data and cycle data) and send it them and then they can do a diagnostic on the battery problem. I can try it if I can find anywhere to buy the cable, although it looks complicated.

It could be a faulty cell, a faulty battery, or some fundamental problem caused by the lack of communication between inverter and battery.

On the other hand sometimes when you are just about ready to go for the nuclear option there appears some extremely simple solution that you´ve overlooked...

Posted (edited)

Can someone let me know please if I can turn off just the one faulty battery when the fault occurs (this would be for minutes, hours, or 1-2 days at max). This would leave one battery turned on and still connected to the inverter via the orange cable.

Can it still work by passing current through the switched off battery to get to the black cable? Is it safe to leave one operating in this configuration and the other off?

Might it be the case that the top battery could still function to charge but not discharge? Or vice versa?

Parallel circuit, see photo.

@Coulomb@Beat

IMG_1033 - Cable Position from April 13.JPG

Edited by Green Power
Posted
17 hours ago, Green Power said:

Can someone let me know please if I can turn off just the one faulty battery when the fault occurs

At first glance I would say yes. It looks like the 2 terminals on each polarity are on the same copper bar. However I don't know how the main switches on the packs are wired up. Do they cut the terminals from the battery directly or via a relay? If they do, then there would be no charge nor discharge.

On my Averge packs there are 125A circuit breakers that cut the terminals from the batteries.

Posted

Sorry for the late reply; life.

I don't know much about Pylontechs, but yes, I think that's OK. The BMS will just not turn on the MOSFETs inside, so that the battery cells will be isolated (not connected to the inverter).

Of course, leaving it off for extended periods of time, even an hour or so, will cause it be be at a different SoC than the other one. It will be good to reconnect when the SoCs happen to match (within a percent or so) when you reconnect. Otherwise, you'll have issues with balancing. Maybe the BMSs can sort this out; I suspect not, but could easily be wrong.

Posted
2 hours ago, Coulomb said:

Sorry for the late reply; life.

I don't know much about Pylontechs, but yes, I think that's OK. The BMS will just not turn on the MOSFETs inside, so that the battery cells will be isolated (not connected to the inverter).

Of course, leaving it off for extended periods of time, even an hour or so, will cause it be be at a different SoC than the other one. It will be good to reconnect when the SoCs happen to match (within a percent or so) when you reconnect. Otherwise, you'll have issues with balancing. Maybe the BMSs can sort this out; I suspect not, but could easily be wrong.

Surely with the 1 battery faulty it does not matter if the faulty one goes to a lower SOC.

I think the wiring will still work OK with the faulty one is switched off.

The BMS in faulty unit should disconnect the battery when reaching the lower level.

Posted (edited)

Summary: If you don't have time to read all this the bottom line is I decided to run the system off one battery until issue is fixed later.

(comment is 880 words, 2 minutes to read)

EDIT June 2022: Suggest skip this long comment for most people, it was a mix of temporary solutions, random asides, and dead ends. It doesn't cover the eventual solution.

The fault has been regularly occurring still. If I turn off the battery and then turn it back on again only minutes later, and do nothing else, the fault never instantly reappears, but will reliably recur minutes or hours later, at the most the next day.

Batteries tend to be out of balance after the fault, especially if I detect the fault at 6am or 7am which means it could have been in the faulty condition for hours as the alarm is not quite loud enough to wake me to the other end of the house. This unbalance (which happened a few times in the last weeks) suggests that when the battery is in the fault condition it is probably not discharging. In some cases when this happened I then disconnected the batteries and did a partial or full rebalancing before connecting. When I did this,  then the fault will not recur as soon, but will still recur after perhaps a few days or a week.

There is insufficient data to draw a conclusion with high probability, but my gut feeling is that the benefit of battery balancing is to give the battery time to rest and recover from heavy demand situations, rather than because of the actual balancing benefit itself. To test this theory I just turned the batteries off for over a day recently and it was 2 days later that the fault occurred. Similar to when I do battery balancing.

Last night I tried turning the one faulty battery off and back on again after only 30 minutes, but the error repeated within a few hours. I then left just one battery off overnight. The single battery was still able to handle a 2000W load. However after turning off the faulty battery a red fault light (no flashing, nothing audible) was displayed on the master battery, and the 6 LED lights on the master battery showing SOC did not display. However it still worked - during steady discharge at low load for maybe 10 hours. I turned the bottom battery back on this morning so I didn't get to test charging with the one battery turned off. When I turned the bottom, faulty battery back on the red fault light disappeared immediately and the SOC lights immediately returned also.

Interestingly, when I turned the batteries back on they were heavily unbalanced with one showing one light and the other four, however, impressively, the two batteries then balanced each other out over a few hours. At one point one of the batteries was actually charging even though the whole system was discharging (i.e. loads > PV input). So all the times I disconnected the batteries to balance them in isolation from the inverter and the rest of the system may not have even been necessary.

I am am able to turn the faulty battery off and on again without causing a power cut if I don't turn off the other battery. This is the only way I've found to reliably create a short term fix to the error without a power cut. However, given the fault light and the non-display of SOC, this makes me uncomfortable as there may be a possibility, however slight, that I could damage the top battery in this arrangement of passing circuit through the turned off battery.

I therefore now completely disconnected (and turned off) the faulty battery for now and connected both long cables to the top battery. I have not changed the dip positions. I have reduced the charging current from 30A to 20A but kept other inverter settings the same. I attach a photo with the current cable connections if anyone wants to check it. I currently plan to only connect it if necessary to do so as part of an attempt to solve the problem or if we had a grid power cut and it's the only power we have left. I am storing the battery at 50% charge level, by the way, and if it gets cold out there (nearer to zero degrees than ten) I will move the battery into another storage location in the house. Given this, it seems like that should be OK to store it for months turned off if necessary (according to a few articles I just read including some graphs).

I'm too busy to properly solve this this week. It looks like the issue needs software diagnostic with Pylontech at this point and failing success with that to try and get the battery replaced or repaired. I will try and get to that within May and then provide an update.

It looks at the moment less likely that the error is caused by communication issues or current flow from the faulty battery to the inverter or the other battery. And perhaps more likely that there is an internal issue with one of the faulty batteries.

I am concerned about running the system with one battery as it is quite undersized for the evening demand. 2000W evening demand will work but is above the recommendation and could affect lifetime. I don't know what happens with 4000W or so demand in the evening, but hopefully would default to grid. However, this seems to be the best solution for now. I may also try this is a permanent solution if I can't get the battery repaired or replaced under warranty.

IMG_1047.JPG

Edited by Green Power
  • 4 weeks later...
Posted

Update: Pylontech told me to buy a RJ45-DB9-USB cable and rewire it to their instruction. I got a computer shop to do that. This then enabled me to, via a software program and some instructions they sent me, take the logs of data out of the battery and send them to Pylontech, who told me that "I think the problem is on the battery BMS board" so they are going to send me a new board.

Posted

As a side comment I note you have not ground your batteries and there is no coms cable to your inverter (no mention which type you have)

Posted

Pylontech had suggested sending the board to me but the installation instructions looked tricky for me so instead it was arranged to leave the battery with the company that sold the battery, where it currently is.

May have further update in June.

Posted (edited)

The battery BMS board (tarjeta de control in Spanish) has been replaced and the battery returned to me and the system is now working again with two batteries

Since the error previously occurred occasionally in the past with gaps of days or weeks in between we won't know for sure if this was the correct solution to stop the error until some time has passed - maybe a month or two.

This also confirms that the guarantee's vaidity has been accepted in spite of using the battery with an inverter with no communication. I was not charged for the replacement.
 

Edited by Green Power

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