Wind Power Energy Output and Force Calculation
What is the energy output a wind turbine can generate? What is the force the mast (pole; holder) of the wind turbine must withstand during strong winds? Check our interactive XLS to see the answer.
LP 12V/20A – customer reference – 530 cycles
I am using LiFePO4 batteries for 1.5 year in a cyclic use. The energy drop after 530 cycles is in average about 2 percent. The batteries have always had higher capacity than given by the manufacturer. At this time they still have higher capacity than the nominal value - in average 110%. I am using 12V/20Ah batteries. I have altogether 50 batteries. The weakest of them still has 21 Ah of useable energy. To get ideal performance, it is best to keep the voltage of each cell in between 3.0 to 3.5V. When voltage is dropping bellow 2.8V the battery may become misbalanced and the cells may be damaged.
FAQ: CAN Bus equipment operation
Question: I have a BMS with CAN option. I have a battery charger with CAN connector, I also have a dash board (display unit) with CAN option. How can I make these components work together over the CAN bus?
Answer: In most cases you need a master CAN bus unit to make the equipment work together. Most of the CAN bus equipment is only either sending data (Read Only mode) or receiving commands (Write Only mode). This equipment has no additional logic to make decisions of operation for other equipment or to control it. The logic of the operation must be set by the master CAN bus unit.
Example: BMS system is sending data (about the status of the battery pack). A ventilator with CAN input is only receiving data (turn on/off and the rotation speed). The BMS itself cannot manage the ventilator. There must be the CAN BUS master unit to process the data from the BMS over CAN and to decide if the temperature is over the limit and when the ventilator is to begin the operation. Then the CAN bus master unit i will send data to the ventilator over the CAN bus.
GWL Tech Report - Long time balancing – a slow way to damage the lithium (LiFePO4) cells
Lithium cell can be destroyed by over charge. The damage by the slow overcharge at balancing level is the most common reason of a gradual damage to the lithium cells. Please study the GWL Technology Report to learn bore about this kind of slow overcharge. The document also gives a practical advice by means of several tips to avoid the damage to the cells by changing the way of cell balancing.
FAQ: Replacing a defective cell with a new cell
Question: I have bought 50 lithium cells. After 3 years, I have found out that one or two cells are defective. How can I replace the defective cell?
Answer: Generally said you can replace a defective cell in a string of LFP cells with a new cell of the same capacity (or higher capacity). As the new call has full capacity performance, the new cell will not influence the performance of the whole pack. Some customers decide to buy some extra cells to have them on hand in case of a cell failure. However in order to keep these extra cells fresh over a period of many years, it is necessary to charge and discharge the extra cells from time to time.
Note: most cell failures are direct results of deep discharge, over charge or improper balancing. We strictly recommend avoiding such situations to keep the long lifetime of the cells.
FAQ: What is the battery inside the EVBike 36V/10A battery pack?
Answer: The battery pack consists of 12 pieces D38120LE cells that are manufactured by Headway and are specified as the 38120 LiFePO4 cells. The nominal capacity of the cell is 10Ah. The EVBike battery is a Li-ion battery using the LiFePO4 cells.
FAQ: What is the capacity of a SuperCap?
The calculation is showed in the picture. For a 6000 F capacitor working with 2.5V nominal voltage, the total energy is 5.2 Wh. Divided by the discharge voltage of 2V, the capacity is 2.6 Ah.
The Result: 6000 Farad SuperCap at 2.5V has about 2.6 Ah capacity. To make a 12V 40Ah SuperCap “battery” you need 112 pieces of 6000 F super capacitors (16P7S configuration). (Source)
FAQ: The difference between Li-ion and LiFePO4 - marking of the products and documents
Question: I have ordered the battery and charger from your company. Your specification says it is the „LiFePO4“ battery and charger. Now, I have received the shipment and I feel puzzled. The invoice form the Customs office says: Tarric Code: 8507 80 30 Lithium-ion cells. The packing list from TNT cargo mentions: Material Safety Sheet for Li-on cells and batteries. The box of the cells has the labeling „Li-on battery“. Even the charger has the text: “Charger for Li-ion battery”. I am afraid you sold me some other cells not the LiFePO4. Is it Li-ion or LiFePO4? Why is LiFePO4 not mentioned in these official documents and on the products?
Answer: Please be sure that we really sell the LiFePO4 technology as mentioned at each of the product or at the cell, at the battery and the equipment specification. We are testing all products that we sell to be sure that the real performance meets the specifications. The products you received are li-on cells with LiFePO4 chemistry.
There are many lithium battery technologies. The global common name for the lithium based products is the „lithium batteries“. The rechargeable batteries based on the lithium technology are globally called as lithium–ion batteries. The worldwide standards used by Customs Office (the HS code), the safety classification (UN standards) all of them have only one large category classification – the lithium-ion cells and batteries. This includes all the different chemistries and internal variations. See also the references of the Wikipedia. Lithium Battery, Lithium-ion battery
Simply said, when somebody speaks about the „li-ion batteries“, then he speaks about the whole group of products and does not give the exact specification of the material used for the technology itself. Please note that the products specification is always listed on our web pages, web blog, the PDF files and the invoices or packing lists. You can be sure that we sell the products that meet the specifications as given by our suppliers and manufacturers.
Visit our company - photos from our office and warehouse
We wish our customer to see that we are a regular company with business office, warehouse, training center, employees, etc. etc. This will give you the trust to co-operate with us. If you wish to get any details or information about our company, please do not hesitate to ask. Check the link with photos here.
You are of cause warmly invided to come to Prague, to see and meet face to face.
Welcome in 2012!
We hope to increase our technical support and services. We plan to add new products, battery brands and models. We are looking forward to co-operation with our customers!
Electorbikes.com - electric cruiser in the retro style
Check at http://www.electorbikes.com/ - using the EVBIKE components from GWL/Power.
