Victron 100/250 overcharging Lithium battery

[Frank Smith]

I replaced my Renogy 60 amp charge controller with Victron 250/100-Tr VE.Can. This feeds a 304 AH Lithium battery with an Apex 28000 BMS. It overcharges the battery to the point where the BMS issues warnings and then shuts down. The warning messages from the BMS are as follows

Monomer high voltage alarm.
Monomer overvoltage protection Total pressure high alarm.
Intermittent power supply waiting. This seems to be the shutdown message.

First, I tried setting the controller with the rotary switch to Lithium (position 7). I am confused by the Absorption Voltage. Do lithium batteries need an absorption setting?

I thought they used bulk until the desired charge state was reached and then switched to a constant voltage mode (float on the Renogy). In float, the controller's output matched my load pretty closely, not charging or discharging the battery. I would like to have this behavior with the Victron.

What do I need to do?

 

[Brucey]

Do you have a smartphone that you can install Victron Connect on? that should allow you to change all settings via bluetooth, including bulk, absorb etc. Can adjust to what was working with the Renigy. The lithium preset can be a little high for some batteries especially if they aren't actively balanced.

 

[DIYrich]

At what voltage do you get thd error?
What are the high and low cell voltages?

 

[Frank Smith]

I have Victron connect and set up a user defined setting. They are the same as the rotary switch lithium settings with 2 exceptions.

Absorption voltage is changed from 56.8 to 53.6
Float voltage is changed from 54 to 53.4.

I will see how this works tomorrow.

Do I understand this right that both float and absorb are constant voltage settings and it doesn't matter which one kicks in after the battery reaches approximately 90% charge?

 

[sunshine_eggo]

Monomer high voltage alarm.
Monomer overvoltage protection Total pressure high alarm.
Intermittent power supply waiting. This seems to be the shutdown message.

Those messages indicate that your BMS is encountering single cell overvoltage likely due to imbalance or due to you changing the defaults to lower numbers. If you've done this, it's a bad idea.

First, I tried setting the controller with the rotary switch to Lithium (position 7). I am confused by the Absorption Voltage. Do lithium batteries need an absorption setting?

Yes. It's the same as "Boost" voltage on the Renogy.

I thought they used bulk until the desired charge state was reached and then switched to a constant voltage mode (float on the Renogy). In float, the controller's output matched my load pretty closely, not charging or discharging the battery. I would like to have this behavior with the Victron.

What do I need to do?

Do this:

Do you have a smartphone that you can install Victron Connect on? that should allow you to change all settings via bluetooth, including bulk, absorb etc. Can adjust to what was working with the Renigy. The lithium preset can be a little high for some batteries especially if they aren't actively balanced.

This also has the benefit of tracking MPPT data on the Trends tab for 46 days (less detail as the data gets older)

Answer this:

At what voltage do you get thd error?
What are the high and low cell voltages?

Additionally, what are your BMS cell protection values?

Absorption voltage is changed from 56.8 to 53.6
Float voltage is changed from 54 to 53.4.

I don't recommend this at all. Your charging will be very irregular.

Do I understand this right that both float and absorb are constant voltage settings and it doesn't matter which one kicks in after the battery reaches approximately 90% charge?

Kinda a moot question. At those charge voltages, there's no certainty you'll hit 90%.

 

[HRTKD]

I think the BMS messages are trying to tell you that you a cell imbalance. One of the cells is hitting a voltage that is higher than the rest of the cells. The BMS needs time to balance the cells (assuming it can balance). With the 56.8 volt setting the cells should have seen no more than about 3.55 volts, which would normally be a good target.

1. Use lower voltage settings. You're already trying that.
2. If #1 doesn't work, lower the charge amps. That will give the BMS more time to balance.

 

[Frank Smith]

Thanks for all the replies.

These values are from when the shutdown happened.
Voltage 56.49 V
Highest Cell 3.650V
Lowest Cell 3.423V

This is later when the battery has discharged to 75% and is not being charged.
Voltage 52.79 V
Highest Cell 3.307V
Lowest Cell 3.286V

BMS Settings
Monomer High voltage alarm 3.5V
Monomer overvoltage protection 3.65V
Total pressure High pressure alarm 56V
Charging Overvoltage protection 63V

Intermittent power supply waiting is not in the setup. I'm guessing this is the BMS disconnecting error message.

The BMS is set to the default values.

 

[Frank Smith]

When a BMS shuts down, does it disconnect the batteries from the output terminals? In my situation, that would leave the charge controller connected to the inverter.

 

[Brucey]

When a BMS shuts down, does it disconnect the batteries from the output terminals? In my situation, that would leave the charge controller connected to the inverter.

Yes but that's not a problem for a Victron SCC. It won't be damaged if there's no battery connected.

 

[Brucey]

These values are from when the shutdown happened.
Voltage 56.49 V
Highest Cell 3.650V
Lowest Cell 3.423V

This is a big Delta. Is this a recently built battery?

 

[Frank Smith]

This is a big Delta. Is this a recently built battery?

Yes. It is a few months old. I noticed the numbers were a lot closer when it was no longer at 99% charge.

 

[Brucey]

Yes. It is a few months old. I noticed the numbers were a lot closer when it was no longer at 99% charge.

It's at a high state of charge when differences will be most apparent.

 

[AlpineJoe]

FWIW, I was running into this on my used CALB bank. I put them into service without top balancing them. Ended up top balancing them, but also changing the boost voltage to 27.6V (24V system). Now all the cells stay nice and even.

 

[DIYrich]

Thanks for all the replies.

These values are from when the shutdown happened.
Voltage 56.49 V
Highest Cell 3.650V
Lowest Cell 3.423V

Absorbe and float at 56.3v until the difference is 0.010v. Then increase in 0.10v increments until you hit your desired charge voltage.

If bms still cuts out at 56.3v, then reduce voltage to the cutoff point, and go from there.

 

[sunshine_eggo]

Absorbe and float at 56.3v until the difference is 0.010v. Then increase in 0.10v increments until you hit your desired charge voltage.

If bms still cuts out at 56.3v, then reduce voltage to the cutoff point, and go from there.

I like this approach, but I would set the voltage at 55.2V or 3.45V/cell