Battery heat problem - What is this resin?

[tigger_na]

5 minutes ago, Tinbum said:

So is it the same over voltage with 2 different types of batteries?

I can't say. I do remember that the bulk charging voltage for the Akkutech battery was higher than I liked, but not sufficiently high to terrify me as this does. As you can see, my bulk charging voltage remains from when it's being reached until the sun disappears. It looks like the BMS is programmed to keep the voltage in the stratosphere until it is starved by the inverter. Why this is is beyond me.

[Tinbum]

8 minutes ago, tigger_na said:

I can't say. I do remember that the bulk charging voltage for the Akkutech battery was higher than I liked, but not sufficiently high to terrify me as this does. As you can see, my bulk charging voltage remains from when it's being reached until the sun disappears. It looks like the BMS is programmed to keep the voltage in the stratosphere until it is starved by the inverter. Why this is is beyond me.

That's a shame.

As you've had, are having, problems with two different types of battery I would certainly check that the inverter is operating correctly.  I don't have or know the KODAK inverter so can't help with settings.

I myself would also sniff the communication CAN bus between the two and see what messages are going through. (Easy enough to do but you do need equipment).

When you removed the CAN cable did the inverter go into fault?

Can you see what the inverter settings are , on a screen (photo) , when the BMS is connected and not connected?

Your battery shouldn't stay at charge voltage for that long unless it is cell balancing but as it's  at 100% SOC I wouldn't think it would be doing that.

[Tinbum]

This is an interesting thread on your first battery;

https://community.victronenergy.com/questions/211798/multiplus-ii-soc-reading-incorrect.html

Last entry-

"So it turns out the underlying problem was that the batteries had different parameter settings on some of them. One had its overvoltage alarm on 54v and its fully charged voltage setting at 52v, so this is why i was getting strange SOC readings, and over voltage errors on the GX. So after a bit of hacking around with PbmsTools.exe and having to guess the admin password, I eventually reset all the parameters on all the batteries! Yay"

 

Says a lot for the brand!!

[Tinbum]

Can you show a photo of the front of the battery? It may well have a branded (Pace) BMS in it from what I have found. If so you can use software to access it and see what the settings are and change them.

 

Edited April 1 by Tinbum

[Scorp007]

At the start of this topic it was indicated that the BMS keeps on changing the volts and amp settings. Based on this on Friday it was indicated to try USR settings to have control over the too high voltage of 58.66V instead of comms. At the same time the inverter can be set to a charge limiting current as low as 10A up to its maximum. It was not that one would just want to disable comms but there is reasons for suggesting it. 

Thus we have some good pointers provided over the weekend. Use any at own risk. 

[Beat]

On 2024/04/01 at 12:09 AM, Tinbum said:

Inverters don't manage at all. They set a voltage and that is it.

You have shown a wonderful graph of battery charge voltage behavior when reaching full charge, allegedly governed by the BMS. Well, my (allegedly not managing) inverters do exactly the same without BMS coms. The determining information they get from the battery is battery voltage. That never lies. On the other hand I noticed that the BMS report 100% SOC while the voltage is far from reaching floating level let alone bulk charge level. The (allegedly not managing) inverters wisely continue charging until bulk charge voltage is reached and then lover to floating level. I wonder what a BMS controlled inverter would do with a faulty 100% SOC information.

[Tinbum]

6 minutes ago, Beat said:

You have shown a wonderful graph of battery charge voltage behavior when reaching full charge, allegedly governed by the BMS. Well, my (allegedly not managing) inverters do exactly the same without BMS coms. The determining information they get from the battery is battery voltage. That never lies. On the other hand I noticed that the BMS report 100% SOC while the voltage is far from reaching floating level let alone bulk charge level. The (allegedly not managing) inverters wisely continue charging until bulk charge voltage is reached and then lover to floating level. I wonder what a BMS controlled inverter would do with a faulty 100% SOC information.

That is not the inverter managing anything it's battery chemistry. Charge a battery with a dumb battery charger and you will see exactly the same.

[Antonio de Sa]

26 minutes ago, Tinbum said:

That is not the inverter managing anything it's battery chemistry. Charge a battery with a dumb battery charger and you will see exactly the same.

I've been running my system for close to three years on inverter voltage settings, pretty satisfied with the results. See dashboard, typical charging curve of 16 cell Lithium 3.2 V cell.  

Edited April 2 by Antonio de Sa

[Tinbum]

47 minutes ago, Antonio de Sa said:

I've been running my system for close to three years on inverter voltage settings, pretty satisfied with the results. See dashboard, typical charging curve of 16 cell Lithium 3.2 V cell.  

That's all very well while the batteries are ok, it's when you get problems with the batteries /cells that things will go wrong. You have an excellent monitoring system, that you use / monitor, so could probably see if their was a problem developing. Most do not.

Inverter control was ok for lead acid as they were forgiving,  Lithium are not. They don't just put inverter control in a BMS for the sake of it- their is a reason.

I've been running mine for over 12 years, first with lead acid and then started on Lithium about 10 years ago.

I'm not saying any more on the subject it's up to you what you do with your own system but giving advice on others is a different matter.

I'm trying to find the best solution to the OP's problem.

Edited April 2 by Tinbum

[Antonio de Sa]

9 minutes ago, Tinbum said:

That's all very well while the batteries are ok, it's when you get problems with the batteries /cells that things will go wrong.

Inverter control was ok for lead acid as they were forgiving,  Lithium are not. They don't just put inverter control in a BMS for the sake of it- their is a reason.

I've been running mine for over 12 years, first with lead acid and then started on Lithium about 10 years ago.

I'm not saying any more on the subject it's up to you what you do with your own system but giving advice on others is a different matter.

I'm trying to find the best solution to the OP's problem.

@Tinbum I'm not giving advice to anybody; I'm simply stating how I run my system and as I said above pretty satisfied. However, the BMS still controls the battery, I've seen it many times if I change the voltage higher than 56.3 V the BMS just stops the inverter from charging the battery. Once the cell voltage gets to 3.55 the BMS goes in to equalizing voltage and stops the inverter from adding any more charge.

[Tinbum]

16 minutes ago, Antonio de Sa said:

@Tinbum I'm not giving advice to anybody; I'm simply stating how I run my system and as I said above pretty satisfied.

Sorry, I know you were not, it was meant as a general statement not aimed at you..

Edited April 2 by Tinbum

[Tinbum]

8 minutes ago, Antonio de Sa said:

However, the BMS still controls the battery, I've seen it many times if I change the voltage higher than 56.3 V the BMS just stops the inverter from charging the battery. Once the cell voltage gets to 3.55 the BMS goes in to equalizing voltage and stops the inverter from adding any more charge.

Yes the BMS will still control the battery but it's not being done in the ideal / safest way. Your example is relying on last ditch protection.

Where I live we get cold temperatures and many see their BMS request lower currents to help protect the battery, the same is true for high temps. This is especially important for those that only have one battery pack that is all too common. How will your system do that to prolong your battery life? Perhaps you dont need it where you are, but others do.

Also one BMS is not the same as the next.

[JayMardern]

This (and the bloating mentioned in the original post) reminds me of the colloquial term used in the repair industry for bulging/bloated mobile-device lithium cells:

"Hand grenade."

If little cells are grenades, I can imagine what they call big ones.

I definitely agree with you in strongly advocating keeping the BMS in the loop for both safety and longevity purposes. Whilst LFP is supposed to be more inert than other lithium-based battery chemistries, risking it isn't worth it unless experienced, able to carefully monitor, and willing to take some (potentially major) safety risks.

Even after I've personally dealt with my own BMS mis-managing top-balancing (and reporting SOC somewhat inaccurately as a result - exactly as described earlier in this thread), I'd rather occasionally deal with that than a house fire.

 

37 minutes ago, Tinbum said:

Yes the BMS will still control the battery but it's not being done in the ideal / safest way. Your example is relying on last ditch protection.

Where I live we get cold temperatures and many see their BMS request lower currents to help protect the battery, the same is true for high temps. This is especially important for those that only have one battery pack that is all too common. How will your system do that to prolong your battery life? Perhaps you dont need it where you are, but others do.

Also one BMS is not the same as the next.

 

1 hour ago, Tinbum said:

That's all very well while the batteries are ok, it's when you get problems with the batteries /cells that things will go wrong. You have an excellent monitoring system, that you use / monitor, so could probably see if their was a problem developing. Most do not.

Inverter control was ok for lead acid as they were forgiving,  Lithium are not. They don't just put inverter control in a BMS for the sake of it- their is a reason.

I've been running mine for over 12 years, first with lead acid and then started on Lithium about 10 years ago.

I'm not saying any more on the subject it's up to you what you do with your own system but giving advice on others is a different matter.

I'm trying to find the best solution to the OP's problem.

 

Edited April 2 by JayMardern

[Scorp007]

4 hours ago, Tinbum said:

That is not the inverter managing anything it's battery chemistry. Charge a battery with a dumb battery charger and you will see exactly the same.

If it is the battery chemistry and neither the inverter nor BMS why do we have this topic being actively helping the OP? 

[Tinbum]

21 minutes ago, Scorp007 said:

If it is the battery chemistry and neither the inverter nor BMS why do we have this topic being actively helping the OP? 

Because the voltage charge setting seems to be too high and for too long.

What I do find strange about the OP's problem is that he has had problems on 2 different brands of battery. Are they poorly setup BMS's in the batteries? Are they the same BMS's? Is it a communication issue? Is it an inverter issue?

We don't seem to have any data on the first battery other than what the supplier said, overheating- which doesn't mean a lot to me without actually seeing graphs of voltage, (temperature ideally) and current .

We need to establish exactly what the problem is and then how to fix it ideally or how do we get round it. Iv'e asked loads of questions but we still seem to be missing some of answers at the moment.. I'm not the sort of person that says lets remove the battery from the smoke detector because it keeps going off. Rather, why does it keep going off?

Edited April 2 by Tinbum

[Tinbum]

If this is a problem with the settings in a BMS or what @Beat is saying about when 100% SOC is or is not not being reached (not in this case) then that problem wants sorting, not just for the OP but for anyone with any BMS. This could be a problem for many people but they just don't know it. Perhaps this case has come to light due to the first failed battery (and the high ambient temperatures).

A BMS has a much more accurate SOC calculation ability than an inverter that is relying on battery voltage. That is if it is set up correctly, if its not then it needs fixing not disconnecting.

Edited April 2 by Tinbum

[Beat]

19 hours ago, Tinbum said:

A BMS has a much more accurate SOC calculation ability than an inverter that is relying on battery voltage.

Agree, the ability is there. However - from my observation with 4 BMS on 4 packs for almost 4 years I presume that they more or less accurately meter Ah in and out, calculate the balance but neglect the internal losses in the batteries. Such shortcoming cannot be overcome with settings, it would be a basic algorithm shortcoming in the firmware.

[tigger_na]

20 hours ago, Tinbum said:

This could be a problem for many people but they just don't know it. Perhaps this case has come to light due to the first failed battery (and the high ambient temperatures).

Exactly. How many users invest in a third-party monitoring system to really be informed what's going on with their investment? Most will only know of their battery when it stops working, by which time it's way too late. 

Why don't these BMSSes  have a default factory-activated *audible* alarm when the relevant limits like OC. OT, UV etc are exceeded? Reminds me of the missing temperature warning light in generations of older cars.

EnerSol has been in touch. We're going to do firmware and calibration things. In the meantime, for until I can get a proper solution, diconnecting inverter to battery comms was the right choice:

[JayMardern]

Disconnecting comms isn't a safety hazard so long as you're not physically bypassing the BMS entirely; you're simply running in voltage mode instead of LiBMS mode which isn't uncommon. In that case, the BMS will still disconnect the battery (even without comms) where necessary. This is good.

 

26 minutes ago, tigger_na said:

Why don't these BMSSes  have a default factory-activated *audible* alarm when the relevant limits like OC. OT, UV etc are exceeded? Reminds me of the missing temperature warning light in generations of older cars.
 

Many do (including my own batteries which I believe run PACE BMSes). If the BMS triggers a fault, the alarm light illuminates, the beeper sounds (unless it's a low-DC-voltage alarm - which remains silent).

And with comms in place that gets taken a step further: the inverter gets the exact notification from the BMS, displays it on-screen, and then (depending on the inverter and setup) can push the alarm to a smartphone.

[Antonio de Sa]

31 minutes ago, tigger_na said:

Exactly. How many users invest in a third-party monitoring system to really be informed what's going on with their investment? Most will only know of their battery when it stops working, by which time it's way too late. 

Why don't these BMSSes  have a default factory-activated *audible* alarm when the relevant limits like OC. OT, UV etc are exceeded? Reminds me of the missing temperature warning light in generations of older cars.

EnerSol has been in touch. We're going to do firmware and calibration things. In the meantime, for until I can get a proper solution, diconnecting inverter to battery comms was the right choice:

@tigger_na I have a Custom-made monitoring system; I can see everything from my inverters and from my battery. Using Modbus protocol. I know from day one that one of my 16 cells do not get to full charge. I still get my battery to charge to 99% SOC, 102 Amps from a max of 105 Amps. 

 

[Tinbum]

57 minutes ago, tigger_na said:

Why don't these BMSSes  have a default factory-activated *audible* alarm when the relevant limits like OC. OT, UV etc are exceeded?

Many do. My pylontech bleeps like hell if something is wrong.

[Beat]

1 hour ago, tigger_na said:

Why don't these BMSSes  have a default factory-activated *audible* alarm when the relevant limits like OC. OT,

Many do. But many user like me have batteries and inverters located in a shack not to get bothered by the fans noise. Mines are in the basement and save in case of fire, I can't hear any alarm. A better feature would be alarm output terminals to connect a remote buzzer.

[Scorp007]

2 hours ago, Antonio de Sa said:

@tigger_na I have a Custom-made monitoring system; I can see everything from my inverters and from my battery. Using Modbus protocol. I know from day one that one of my 16 cells do not get to full charge. I still get my battery to charge to 99% SOC, 102 Amps from a max of 105 Amps. 

Just because one can measure a value does not mean one should have sleepless nights about it. Rather monitor if it gefs worse. Just my take on the 1% SOC. 

@tigger_na Very few if any inverter is built to suit us all. If wired output terminals are provided we can always wire them to suit our needs as @Beat indicated. I also use a light in the kitchen the moment a low battery level alarm comes up on the screen. This happens mostly when we have a high load like a micro running on my 24V Axpert. It then goes off when the micro is off.