New 200 ah Aims LIP battery single cell problem

[Bigfoot9.6]

Hi all, new here but watch all Will's videos.
I recently purchased a new Aims 200ah battery.
It has a BT BMS so I can monitor the cell voltages and some other status readings.
If I am charging the battery to 100% with 14.4 vdc or 13.6 and the battery gets to about 98% one cell will continue to
charge and when it gets to the BMS Voltage cutoff of 3.8 the BMS shuts of the charge. When the voltage drops to
the Over Charge Release voltage of 3.6 the current jumps up, and the voltage of that cell quickly rises to the cutoff
voltage. This cycle continues until I turn off the charger/converter or lower the voltage to 13.2.
The other cells remain at 3.438-3.454, or they're about. The current when it does this if at 14.4 charge will be around 26 amps.
This cell also has a sizable difference in the voltage as it is discharged past about 20%soc, other cells at 3.1xx and this cell at 2.8.
It will cause the BMS to shut down at about 10% SOC.
When the battery BMS shows 100% and I turn off the charger/converter the BMS will balance this and the other cells quite nicely.

I am measuring SOC etc with the Victron smart shunt and watching the Aims BT cell voltage.

Aims support says as long as the BMS battery capacity is showing 200ah it is ok.
I am going to have another discussion next week with them.
Would like to read what you folks say.

I have two buds that are running multiple Aims 200ah batteries and they see nothing like this.

Jim.

 

[chrisski]

Aims recommends you charge the battery 14.4-14.6 volts. 14.6 is 3.65 volts per cell.

If a cell is reaching 3.8 volts it seems the cells are out of balance. Can you post a picture or screen shot of the cell rating?

The other thing that might have happened during a charge with a power supply is if charging voltage was set to 14.6 after connecting the power supply, this can cause cells to overcharge and perhaps ruin a battery.

 

[mikefitz]

Would like to read what you folks say.

I think some of you voltage values are mis typed, example, 13.2 volts should read 14.2 volts.
If you have no cell overvolts at a charge voltage of 14.2 volts then use this as the charge voltage. It should still be high enough for cell balance taking place, ( confirm via BT). Perhaps set a long absorbtion period to give more balance time.

a sizable difference in the voltage as it is discharged past about 20%soc, other cells at 3.1xx and this cell at 2.8

There will always be inbalance at low cell volts. It may improve as the top gets more in balance.

Aims support says as long as the BMS battery capacity is showing 200ah it is ok.

If you are getting 200 Ah, then why worry?
It's understandable that you have concerns but many low ( and high) cost batteries will have similar performance.
I would be more concerned about 3.80 cell overvolt than less than ideal balance.

 

[Tomthumb62]

If you are getting 200 Ah, then why worry?

Bluetooth BMS must give these batteries manufacturers ongoing headaches when ignorant people like me buy one of these and start asking a ton of questions as to why the BMS is reporting X, Y or Z results.

Without the ability to peer inside the state of the battery via an app, people will have no idea that their battery is have any “issues” and are getting 98.9% capacity anyway.

 

[Bigfoot9.6]

Aims recommends you charge the battery 14.4-14.6 volts. 14.6 is 3.65 volts per cell.

If a cell is reaching 3.8 volts it seems the cells are out of balance. Can you post a picture or screen shot of the cell rating?

The other thing that might have happened during a charge with a power supply is if charging voltage was set to 14.6 after connecting the power supply, this can cause cells to overcharge and perhaps ruin a battery.

My converter is 14.4 for charge. 13.6 for absorb.

Here is the settings for the Aims BMS.

 

[Bigfoot9.6]

I think some of you voltage values are mis typed, example, 13.2 volts should read 14.2 volts.
If you have no cell overvolts at a charge voltage of 14.2 volts then use this as the charge voltage. It should still be high enough for cell balance taking place, ( confirm via BT). Perhaps set a long absorbtion period to give more balance time.


There will always be inbalance at low cell volts. It may improve as the top gets more in balance.

If you are getting 200 Ah, then why worry?
It's understandable that you have concerns but many low ( and high) cost batteries will have similar performance.
I would be more concerned about 3.80 cell overvolt than less than ideal balance.

I set the converter down to 13.2 just to see what would occur with the BMS. It did bring down the #4 cell voltage down to balance with the others. My converter is settable to 14.4 bulk, 13.6 absorb and 13.2 for float. It can be automatic. I only use it to get periodic 100% SOC.
Yes it is the 3.8 that concerns me. The low voltage disconnect is not bothersome, only that the other 3 cells have quite a ways to to do low voltage disconnect.
Jim.

 

[Bigfoot9.6]

Bluetooth BMS must give these batteries manufacturers ongoing headaches when ignorant people like me buy one of these and start asking a ton of questions as to why the BMS is reporting X, Y or Z results.

Without the ability to peer inside the state of the battery via an app, people will have no idea that their battery is have any “issues” and are getting 98.9% capacity anyway.

Most Batt mfg do not have BT, thus ignorance is bliss. The Aims BMS is not a good tracker of ah, but the cell voltage is a good tool for the tech types. The bad is if the MFG's are not selling nice balanced cells they will get caught. hahahaa
The Aims battery is not a cheapie! It touts cylindrical cells etc and compared to other battery weights the Aims is like the Battle Born... heavy!
I use the Victron Smart Shunt for Ah.
Jim.

 

[Tomthumb62]

The bad is if the MFG's are not selling nice balanced cells they will get caught. hahahaa

Yep they will get caught. Imbalanced cells isn't all that bad until they get really out of balance. Then instead of getting 98-99% capacity, you're getting 70-80%. That's when you need to spend some time with special charging methods to help the BMS encourage self-balancing, assuming the BMS has passive balancing functions built-in.

The Aims battery is not a cheapie! It touts cylindrical cells etc and compared to other battery weights the Aims is like the Battle Born... heavy!
I use the Victron Smart Shunt for Ah.

Huh, this is interesting. FYI, @Will Prowse recently took Battleborn off his recommended list of batteries. Long story short (there is a good thread on the topic), Battleborn has two main problems:

• The thread in question (sorry I don't have a direct link handy), demonstrates a fatal flaw in Battleborn's warranty: The warranty excludes manufacturing defects and only includes damaged caused by improper design. So if your Battleborn arrives with the positive and negative leads hooked up backwards, tough shit.
• Battleborn is no longer competitive. They are very expensive compared to the cheaper options out there now, some of which have actual warranties with teeth. Look at the threads and comments with positive results with people getting warranty replacements by CHINS and LiTime and AmpereTime and others.

So if AIMS is producing Battleborn-like replacements for less $$ and has a real warranty, then anyone who wants a Battleborn ought to look seriously at the AIMS. I will not buy AIMS products though, because @HighTechLab aka Current Connected shared their experience with AIMS not honoring a warranty on hundreds (thousands?) of AIMS chargers that had factory defects. So CC cut their ties with AIMS, since they lost trust and a lot of money. Some of these defective AIMS chargers were causing fires, if I recall correctly. But there's also that famous video (I think it's been removed from Youtube) where the guy videoed his 8 Battleborn batteries causing a fire. He had something wonky in his wiring, but it did demonstrate that the BMS's had failed to prevent such fires from happening. So I can't say that Battleborn or AIMS are any safer than a $275 LiFePO4.

Finally, as a plug for a GOOD battery, at a GOOD price, I recommend the Powerurus batteries. Not as expensive as the Battleborn or SOK but not as cheap as the LiTime or CHINS. I bought one earlier this year and love it...and their customer support has been simply AWESOME...they answer all my stupid questions, without complaint. It's actually one of the recommended budget buys on Will Prowse's website:

LiFePO4 Batteries for Offgrid and Mobile Solar

The lithium batteries below are considered "Drop-in Lead Acid Replacement" because you can use them with standard 12/24/48 volt solar charge controllers/chargers/inverters and more. Simply hook them...

www.mobile-solarpower.com

 

[Alkaline]

The bad is if the MFG's are not selling nice balanced cells they will get caught. hahahaa

Yep which is why many budget brands stopped selling batteries with monitoring because pesky customers start asking too many questions!

 

[Will Prowse]

Yep they will get caught. Imbalanced cells isn't all that bad until they get really out of balance. Then instead of getting 98-99% capacity, you're getting 70-80%. That's when you need to spend some time with special charging methods to help the BMS encourage self-balancing, assuming the BMS has passive balancing functions built-in.


Huh, this is interesting. FYI, @Will Prowse recently took Battleborn off his recommended list of batteries. Long story short (there is a good thread on the topic), Battleborn has two main problems:

• The thread in question (sorry I don't have a direct link handy), demonstrates a fatal flaw in Battleborn's warranty: The warranty excludes manufacturing defects and only includes damaged caused by improper design. So if your Battleborn arrives with the positive and negative leads hooked up backwards, tough shit.
• Battleborn is no longer competitive. They are very expensive compared to the cheaper options out there now, some of which have actual warranties with teeth. Look at the threads and comments with positive results with people getting warranty replacements by CHINS and LiTime and AmpereTime and others.

So if AIMS is producing Battleborn-like replacements for less $$ and has a real warranty, then anyone who wants a Battleborn ought to look seriously at the AIMS. I will not buy AIMS products though, because @HighTechLab aka Current Connected shared their experience with AIMS not honoring a warranty on hundreds (thousands?) of AIMS chargers that had factory defects. So CC cut their ties with AIMS, since they lost trust and a lot of money. Some of these defective AIMS chargers were causing fires, if I recall correctly. But there's also that famous video (I think it's been removed from Youtube) where the guy videoed his 8 Battleborn batteries causing a fire. He had something wonky in his wiring, but it did demonstrate that the BMS's had failed to prevent such fires from happening. So I can't say that Battleborn or AIMS are any safer than a $275 LiFePO4.

Finally, as a plug for a GOOD battery, at a GOOD price, I recommend the Powerurus batteries. Not as expensive as the Battleborn or SOK but not as cheap as the LiTime or CHINS. I bought one earlier this year and love it...and their customer support has been simply AWESOME...they answer all my stupid questions, without complaint. It's actually one of the recommended budget buys on Will Prowse's website:

LiFePO4 Batteries for Offgrid and Mobile Solar

The lithium batteries below are considered "Drop-in Lead Acid Replacement" because you can use them with standard 12/24/48 volt solar charge controllers/chargers/inverters and more. Simply hook them...

www.mobile-solarpower.com

Yeah the powerurus is a fantastic buy. People usually just buy LiTime or Chins but powerurus for the money is amazing