As we have done in the yearly ving card maintenance in our property. After this we need Maintenance Team to change a battery and clean the battery blanket (มีสนิมเเละคราบเกลือ) as summery in the excel file you can find from attached.
More over I have some recommend ''how to clean and maintain ving card system'' from P' Chart (staff from ving card company) please see the recommendation below
1. Velvet card and Tape cleaning spray we can use everyday
2. Battery should be change twice a year
3. Cleaning process ( หัวอ่านเเละรางถ่าน) should be clean very 4 months