In the face of the mature lead-acid batteries on the market, we often find that the battery is not far away and there is no problem with the quality of the battery. How to deal with this situation? Now, let me talk about my method. 1 Look at the weight of the battery 12AH only one is not above 4.2KG. There is no 7KG for 20AH. 2 Is there a manufacturer on the battery and whether the date of manufacture is within one month? 3 See if there is any contact information. 4 Whether the warranty time is 12-15 months. Want an invoice or receipt. 5 Discharge test 5-35 degrees. The standard 12AH is 5A discharge for more than 145 minutes, and the 20AH battery is 10A discharge for more than 120 minutes.