GENERAL
What does the serial number on Winston cells mean?
Example for TSWB-LYP200AHA 230508:” TSWB” means the abbreviation of the brand” Thunder Sky Winston”; “LY” means positive electrode of lithium yttrium oxide active material; “P” means prismatic; “200AH” means cell nominal capacity; “A” means cathode and anode terminal of the cell are the same directions; “230508” means produced on May 8, 2023.
What is the operating temperature of Winston cells?
The specification for the ambient temperature is given at -45°C to 85°C. The typical operational temperature of the cells (at the surface) is at 0°C to 40°C (max 60°C). The internal temperature under load should not exceed the maximal limit (<85°C), which is why the surface temperature of the cell should be kept within a limit of 40°C (to 60°C).
Are LFP cells classified as dangerous goods?
LFP cell is considered Class 9 dangerous cargo for any transportation. This is due to the chemical composition. Additionally, for the transportation of LFP cells, the IATA regulations require the cells to be charged to less than 30% of the nominal capacity. As a result, the cells are always transported with 30% or less capacity, and they should be recharged quickly when reaching the destination.
Can I use Winston cells as soon as I receive them from the manufacturer?
The new 3.2V Winston cells delivered from the manufacturer are partially charged. However, before the first use, it is essential to charge each cell to full capacity. The initial charging should be done with the charging current set to less than 1C (typically 0.5C), till the voltage level of 3.65 V is reached.
I need to connect several cells in parallel; what type of connection should I use?
It is always recommended to use a flexible connection. Never use the fixed harness made of copper rod consisting of a solid material with no flexibility.
Can Winston cells be laid on their side?
Generally, it is recommended to have the terminals mounted in the top (upside) position, mainly because of the internal design of the cells and the fact that the safety vent needs to be on top to work properly.
Other positions of cells are not recommended. It can damage the cells or shorten the life of the cells or their proper functioning.
CHARGING & DISCHARGING
What is the voltage of the Winston LFP cells under the load?
The voltage of the LFP cells under load is typically above 3V. The cell is nearly discharged if the voltage gets under 3V, and the remaining capacity is limited.
Can Winston LFP 60 Ah cell withstand loads of 150/180 Ah for 10/15 seconds?
Yes, the Winston LFP cell supports the continued discharge of 3C. This means you can discharge the 60Ah cell with up to 180 Amp. For peak discharge, you can make peaks of 10C (600Amp) for 10 seconds.
If I discharge with 3C or 10C rates, how about the temperature of the cells?
For any high-speed discharge application, it is recommended that you observe the temperature. The temperature should stay between 20°C and 40°C. If the temperature increases, reduce the charging // discharging current or use ventilation (airflow) to cool the cells down.
Can I charge a 12V LFP battery with a sealed lead acid battery charger?
We recommend that you do not charge a LFP battery with a lead acid charger. LFP batteries are unlike lead acid and chemically react differently during a charging cycle. A LiFePO4 battery charger has a higher voltage per cell as well as tighter voltage to tolerances during the different charging stages and no third stage during which the charger switches to a trickle/float charge setting, which is not required for an LFP battery.
Why is it important to balance during charge?
Due to the way LFP batteries are constructed from many cell blocks, it is very important that these cell blocks are allowed to balance (i.e., reach the same charge level) during charging. Otherwise, the cell block, which is the lowest charge state, would limit the total battery output performance.
This balancing should be performed as often as possible to keep the overall capacity optimum and ensure that all cells within a pack contribute equally to the total output.