Charging LiFePO4 battery with Victron Blue Smart charger Li-Ion Setting

[max514]

I just received a new SOK 206Ah battery I ordered forever ago and I want to charge it with my Victron Blue Smart 15A charger. The charger has a Li-Ion setting but no mention of LiFePO4 anywhere. I read a thread that said that the Li-Ion settings are not applicable to LiFePO4 batteries. Is this true? How can I charge this battery properly (and safely)?

 

[mikefitz]

Regard the Li ion setting as a error in the instructions. The value of 14.2 charge volts and 13.5 float volts is a good starting point.
It's easy with the app to modify the charge profile for more ideal settings for your battery and application.
Depending how well balanced the cells are in your SOK battery, the charge, absorbtion, volts may have to be reduced if you get BMS shutdown due to cell overvolts.

Mike

 

[rmaddy]

I used a Victron Blue Smart charger to initially charge my 2 SOK 12V 206Ah LiFePO₄ batteries. It worked great using the Li-ion preset battery type. I may have tweaked the Absorption voltage from the default of 14.2V to 14.6V for that initial charge since SOK shows a recommended charge of 14.6V.

I've only charged my batteries twice, a year ago, with that charger so I can't speak to how well it would work if that was a daily charger.

Do note that in the advanced settings there is a battery preset for "Smart Lithium (LiFePO₄)".

 

[mikefitz]

I do not understand why SOK recomend a charge voltage of 14.6 and a float of 13.8 volts

Perhaps it's a method to sell more batteries.

Mike

 

[max514]

I do not understand why SOK recomend a charge voltage of 14.6 and a float of 13.8 volts

Perhaps it's a method to sell more batteries.

Mike

After I posted, I got an email from the seller and they gave me:

Bulk charge: 14.6V
Absorption charge: 14.6V
Float charge: 13.8V
Charged voltage: 13.8V

Why does 14.6 sell more batteries? I don't understand your comment..

 

[Jack Rabbit Off Grid]

After I posted, I got an email from the seller and they gave me:

Bulk charge: 14.6V
Absorption charge: 14.6V
Float charge: 13.8V
Charged voltage: 13.8V

Why does 14.6 sell more batteries? I don't understand your comment..

14.6 is getting pretty close to the upper limit. I just use the lithium setting 14.2 13.5.

I also have a 12v and 48v Victron charge controllers. I just use the lithium setting on both. I’ve messed with the settings before and ended up with unbalanced cells and packs.

 

[max514]

After I posted, I got an email from the seller and they gave me:

Bulk charge: 14.6V
Absorption charge: 14.6V
Float charge: 13.8V
Charged voltage: 13.8V

Why does 14.6 sell more batteries? I don't understand your comment..

Well, I've been charging at 14.6V for a few hours. I'll post results and cell voltages when the charge is complete.

 

[mikefitz]

High charge and float voltages stress the cells and may cause accelerated ageing, thus the battery capacity falls significantly within a few years and you need to buy a new one.
14.6 volts with 4 cells in the battery is 3.65 volts per cell if the the cells are perfectly bananced. Its most unlikely the cells will be in balance and the BMS will shut down charging at a voltage lower than 14.6 due to a cell going over voltage.

Mike

 

[Kemills1]

High charge and float voltages stress the cells and may cause accelerated ageing, thus the battery capacity falls significantly within a few years and you need to buy a new one.
14.6 volts with 4 cells in the battery is 3.65 volts per cell if the the cells are perfectly bananced. Its most unlikely the cells will be in balance and the BMS will shut down charging at a voltage lower than 14.6 due to a cell going over voltage.

Mike

Agreed. I also think it’s wrong to claim this charger is suitable for LiFePo4 chemistry when there appears to be no provision for low temp charge cut off protection.

 

[Kemills1]

After I posted, I got an email from the seller and they gave me:

Bulk charge: 14.6V
Absorption charge: 14.6V
Float charge: 13.8V
Charged voltage: 13.8V

Why does 14.6 sell more batteries? I don't understand your comment..

SOK have to push the charging parameters to the absolute max for the cells to achieve the claimed Ah capacity. Higher capacity claims sell more batteries.

 

[Rick Legrand]

SOK have to push the charging parameters to the absolute max for the cells to achieve the claimed Ah capacity. Higher capacity claims sell more batteries.

So what charge parameters are you guys suggesting to prevent future battery damage.

 

[Jack Rabbit Off Grid]

So what charge parameters are you guys suggesting to prevent future battery damage.

14.2 bulk 13.5 float. Factory Victron settings I believe.

 

[Kemills1]

Andy from off grid garage on YT has done a lot of testing of LiFePo4 cells and his videos provide a lot of insight as to characterists of the cells. There is a lot of useful info there regarding charging.