LiTime LTCP 280ah only 13.4 volt charged voltage

[Amplion]

So I just got my battery yesterday and I started to charge it. When I got the battery voltage was 13.08 volt. Then now after charging it for like 18 hours voltage is only 13.4 volts and my charger has stopped charging saying the battery is full. According to Victron smart shunt the highest voltage was 13.52 volts and amp was almost constant 7.75 Amp during the whole charge process except a brief period in the beginning when voltage and current was lower.

This is the charger i've been using Charger 12 volt 10amp

So is my battery bad or is it the charger that somehow cant charge my battery enough? According to charts ive seen 13.4 volts should be around 90% charge only. I'd like to charge it to 100% to test its capacity.

Edit. Voltage is now 13.38 Volt resting

 

[Rednecktek]

Does the battery have bluetooth? You can check the cells and see what they're doing.

If not, you might just have a runner cell and the BMS needs time on the charger to shuffle stuff around and get everything topped off.

Make sure it's in Lithium mode, the Lead and AGM won't get fully up to voltage. Odds are when you put the battery into service your SCC will also be high enough voltage to get everything balanced out.

 

[Amplion]

Does the battery have bluetooth? You can check the cells and see what they're doing.

If not, you might just have a runner cell and the BMS needs time on the charger to shuffle stuff around and get everything topped off.

Make sure it's in Lithium mode, the Lead and AGM won't get fully up to voltage. Odds are when you put the battery into service your SCC will also be high enough voltage to get everything balanced out.

My battery is a non BT version unfortunately. I used the chargers lifepo4 mode, was kinda weird to see it never going above 13.52 volts when charging as I expected it to go into absorption mode above 14 volts but it never did.

This is the volt and amp curve

 

[mikefitz]

Voltage is now 13.38 Volt resting

The battery is very near full charge. As received it was at 50 to 60 % SOC, say 140Ah. You charged at 7.75 for 18 hours, that's 139Ah.
I consider 13.40 resting as full, if the cells were slightly better balanced you may get the extra few Ah into the battery.
One of the cells was reaching cell overvolts protection level and stopping the charger process.
To give more time for balancing to take place lower the charge volts to 13.5 and hold this for several hours.

For interest I suggest carrying out a discharge test in the current state to see the capacity in the inbalanced state.

The automotive charger you used is not ideal for charging lithium, there are better chargers available.

 

[Amplion]

The battery is very near full charge. As received it was at 50 to 60 % SOC, say 140Ah. You charged at 7.75 for 18 hours, that's 139Ah.
I consider 13.40 resting as full, if the cells were slightly better balanced you may get the extra few Ah into the battery.
One of the cells was reaching cell overvolts protection level and stopping the charger process.
To give more time for balancing to take place lower the charge volts to 13.5 and hold this for several hours.

For interest I suggest carrying out a discharge test in the current state to see the capacity in the inbalanced state.

The automotive charger you used is not ideal for charging lithium, there are better chargers available.

What I dont get is how 13.52 volt can trigger overvoltage protection within the BMS. Thats only 3.38V per cell on avg. Only way is one cell is off by a large margin. Its probably close to maxed out, but working range should be slighly higher shouldnt it? But in the same time I dont know what parameters LiTime are using within their bms, their trigger could be set low for all i know.

I reconnected the charger and the battery seems to take on charge again. Voltage is 13.55V now and still providing 7.75 amps. Maybe the cells are balancing out

 

[mikefitz]

Maybe the cells are balancing out

On each charge cycle there will be an improvement.

dont get is how 13.52 volt can trigger overvoltage protection within the BMS.

It does seem improbable that one cell would be that far out of balance, perhaps it's the characteristics of the charger.
Since you are charging at a low current compared to battery capacity its possible you have reached near full charge at 13.5 volts.
The fact that you put 139 Ah into a 280 battery received at an estimated 50% SOC, supports the fact that you are near full charge.
The chart below shows the capacity reached with different charge volts,

 

[Q-Dog]

Are you using the charger's voltage reading? or are you measuring at the battery terminals? do the 2 readings match? Measure while charging and while at rest.

 

[Amplion]

Are you using the charger's voltage reading? or are you measuring at the battery terminals? do the 2 readings match? Measure while charging and while at rest.

I use a victron shunt for the voltage reading. Cables are fairly short. I also use a multimeter and it seems to match. While charging its now at 13.55 Volt still allowing current to flow in @ 7.75 Amps. Last time i checked it was at 13.37 volt resting before I restarted the charging.

 

[Amplion]

On each charge cycle there will be an improvement.
It does seem improbable that one cell would be that far out of balance, perhaps it's the characteristics of the charger.
Since you are charging at a low current compared to battery capacity its possible you have reached near full charge at 13.5 volts.
The fact that you put 139 Ah into a 280 battery received at an estimated 50% SOC, supports the fact that you are near full charge.
The chart below shows the capacity reached with different charge volts,
View attachment 259437

Ok so the voltage my charger provides should be sufficient to get to pretty much 100% SOC then bar one amp maybe, thats good to know. Ill probably do a capacity test soon to see what i can get out of it

 

[Amplion]

Update: The battery is now charging at 14.1 Volts and the amperage seems to start tapering . Seems like a few hours pause after last charge stopped did the trick. Since it has been charging now for more than 2 hours with 7.75 Amps I should get like 15-16Ah more for the capacity test.

Edit: Charging just stopped. Resting voltage seems to be at 13.50V now but its tapering off a bit so going to wait a while and see what happens. Before I do the capacity test

 

[Amplion]

 

[repono]

Update: The battery is now charging at 14.1 Volts and the amperage seems to start tapering . Seems like a few hours pause after last charge stopped did the trick. Since it has been charging now for more than 2 hours with 7.75 Amps I should get like 15-16Ah more for the capacity test.

Edit: Charging just stopped. Resting voltage seems to be at 13.50V now but its tapering off a bit so going to wait a while and see what happens. Before I do the capacity test

That sounds like a full charge to me. Did it reach any higher than 14.1V? LiTime charging spec is 14.4V +/- .2V. I have several LiTime batteries and they seem to need a few charge cycles to top balance when new. 13.5V resting is perfect, the capacity test should go well!

 

[Amplion]

That sounds like a full charge to me. Did it reach any higher than 14.1V? LiTime charging spec is 14.4V +/- .2V. I have several LiTime batteries and they seem to need a few charge cycles to top balance when new. 13.5V resting is perfect, the capacity test should go well!

I bought a victron 25A charger and now charging with 14.2 volt absorption. The discharge test went ok I guess but i was hesistant to run the battery all the way down for bms cutoff. I stopped around 11.9volt. As it was around 270 Ah maybe i could reach 280 if i stretched it. As you point out i suspect the cells are not top balanced so ill charge back up again and let bms do its thing.