Battery test

Battery test: due to the randomness of the battery production conditions, the produced battery performance is different, so in order to effectively combine the battery pack together, it should be classified according to its performance parameters; the battery test tests the size of the battery output parameters (current and voltage). To improve the utilization rate of the battery, make a quality-qualified battery pack.

2, front welding: welding the confluence belt to the main grid line of the battery front (negative pole), the confluence belt is tin plated copper belt, and the welding machine can spot the welding belt on the main grid line in a multi-point form. The heat source for welding is an infrared lamp (using the thermal effect of the infrared). The length of the welding band is about 2 times the length of the battery edge. Multiple weld bands are connected to the back electrode of the rear battery piece during back welding

3, back serial connection: Back welding is to string 36 batteries together to form a component string. The process we currently adopts manually, the battery is mainly positioned on a membrane plate with 36 grooves for the battery, the size of the battery, the groove position has been designed, different specifications use different templates, the operator uses soldering iron and tin wire welding the front electrode (negative electrode) of the “front battery” to the back electrode of the “back battery”, so that 36 strings together and welding the positive and negative electrode of the assembly string.

4, lamination: after the back is connected and qualified, the component string, glass and cut EVA, glass fiber and back plate shall be laid at a certain level and ready for lamination. Glass is precoated with a reagent (primer) to increase the bonding strength of glass and EVA. When laying, ensure the relative position of the battery string and glass and other materials, adjust the distance between the batteries, and lay the foundation for lamination. (Layer level: from bottom up: glass, EVA, battery, EVA, fiberglass, backplan

5, component lamination: Put the laid battery into the lamination, draw air from the assembly by vacuum, then heat the EVA to melt the battery, glass and back plate together; finally cool out the assembly. Lamination process is a key step in component production, and the lamination time is determined according to the nature of EVA. We use rapid curing EVA with a laminate cycle time of about 25 minutes. The curing temperature is 150 ℃.
6, trimming: EVA melts outward due to pressure to form the margin, so it should be removed after lamination.

7, Frame: similar to installing a frame for the glass; installing an aluminum frame for the glass assembly, increase the strength of the component, further seal the battery pack, and extend the service life of the battery. The gap between the border and the glass assembly are filled with silicone. The borders are connected with corner keys.
8, Welding Terminal Box: Welds a box at the back lead of the assembly to facilitate the battery connection to other equipment or batteries.

9, High voltage test: High voltage test refers to the applied voltage between the component frame and electrode leads, testing its voltage resistance and insulation strength to prevent the assembly from damage under harsh natural conditions (lightning strikes, etc.).

10. Component test: The purpose of the test is to calibrate the output power of the battery, test its output characteristics, and determine the quality grade of the components.