Problem with new Li Time 12v 200ah batteries not Fully Charging

[lonewolf754]

I purchased four new Li Time 12v 200ah batteries from Amazon on February 17, 2023.

These batteries will not get to (14.2-14.6v). I believe that the BMS is cutting off charging because of too high voltage on a cell group and are not properly balanced or they were not properly matched, etc.

Li Time is stating that they believe that the chargers that I use are the problem and they see nothing wrong with these batteries.

Here are the chargers that I have used trying to get these batteries up to full voltage. All of these chargers will
charge with CC/CV.

These chargers work with my Battle Born 12v 100ah batteries
with no issues.

Has anyone here had success getting these particular batteries fully charged to 14.4v with any of these chargers?

This is where the chargers are stopped, this is not their resting voltage, this is the maximum voltage that I can get them to.

(battery 1: 14.18v) (battery 2: 13.94v) (battery 3: 13.97v) (battery 4: 13.90v)

Thank you.

 

[BentleyJ]

Take battery 1 for example. If the cells need to be top balanced one way is to let the BMS do it but this will take some time with a float charge since balance currents tend to be small especially if the BMS only has passive balancing capability. Reduce the charger CV to 14.0V (just below where its cutting off) and let it float for 24 hours. Then turn up the CV setting to 14.2V and see if the BMS cuts out. If not let it float at 14.2V for another 24hr. Increase to 14.3V for another 24hr. At 14.3V that's 3.575V per cell which would be enough to fully charge the battery over that extended period of time.
Likewise with the other batteries using appropriate CV float settings just below the cut out point.

 

[lonewolf754]

Take battery 1 for example. If the cells need to be top balanced one way is to let the BMS do it but this will take some time with a float charge since balance currents tend to be small especially if the BMS only has passive balancing capability. Reduce the charger CV to 14.0V (just below where its cutting off) and let it float for 24 hours. Then turn up the CV setting to 14.2V and see if the BMS cuts out. If not let it float at 14.2V for another 24hr. Increase to 14.3V for another 24hr. At 14.3V that's 3.575V per cell which would be enough to fully charge the battery over that extended period of time.
Likewise with the other batteries using appropriate CV float settings just below the cut out point.

Thank you for responding and I will definitely try your suggestions at a later time if it's my last option.

These are brand new batteries. Never put into service.

I am trying to determine as to whether these chargers are the problem, or the batteries have the problem. If it's the batteries, then I expect Li Time to replace these batteries with ones that are balanced and functioning properly. Maybe even testing them before sending them out.

They believe that the chargers are the problem, not their batteries. That's what I'm hoping to find out. If Li Time is correct, then I will
definitely purchase a charger after it is proven to work with these batteries.

If someone has used one of the chargers shown above and has successfully fully charged and balanced these particular batteries, please inform
me of this and I'll know what my options are.

Thank you, I appreciate your help.

 

[mikefitz]

I don't think the chargers are an issue, expecting low cost batteries to be well balanced is over optimistic.
Since you are charging with low current, the batteries will be almost fully charged by the time they reach 13.9 to 14 volts.
Set your power supply to just below the volts where the BMS disabled charging and leave connected for several hours. This will give the balance circuits time to bleed down the high cells.
Balance will improve and you should be able to increase the charge voltage for future cycles.
You may decide to return the batteries for replacement, if the vendor agrees, but there is no guarantee any replacements will be an improvement.

Mike

 

[lonewolf754]

I don't think the chargers are an issue, expecting low cost batteries to be well balanced is over optimistic.
Since you are charging with low current, the batteries will be almost fully charged by the time they reach 13.9 to 14 volts.
Set your power supply to just below the volts where the BMS disabled charging and leave connected for several hours. This will give the balance circuits time to bleed down the high cells.
Balance will improve and you should be able to increase the charge voltage for future cycles.
You may decide to return the batteries for replacement, if the vendor agrees, but there is no guarantee any replacements will be an improvement.

Mike

Thank you for your recommendation Mike, I appreciate the help. I have copied and saved your advice along with BentleyJ's.

I will first attempt to charge with the charger that Li Time sent me as I requested. Which will be a while because they sent me a 220v
charger and I need a 120v charger.

Li Time told me that the batteries need to get to 14.2v at least before I hook them into parallel for 24hrs as per their instructions. So far the
batteries aren't meeting their minimum requirements they advertised on Amazon. If I could open them up, I'd just balance them one by one with my bench charger as I did my 280 cells. Won't be perfect because they welded the cells together so I can't parallel them.

Thanks again.

 

[CJLDAD]

Lonewolf, did you ever resolve this situation? I have some of their 100ah units from the same time period and they are cutting out right around 14v as well..