Many people have bad habits. They often leave the electric bike battery on the bike when they are not at home, leave the air switch on, and don't use it for several months. When they come to ride it again after several months, they find that the bike has no power and cannot be charged. Even when the charger is plugged in, it remains green, even if it is plugged in for 24 hours, because the battery voltage is too low and the difference between the output voltage of the charger and the battery voltage is too large. The charger cannot charge the battery.
This situation is what people usually call the battery being "starved". The voltage of this type of battery block battery is generally around 5.6V, and it will not exceed 6V. For such batteries, most people replace the battery. But replacing a set of batteries costs several hundred yuan, and it is a bit of a pity to do so, especially for batteries that have just passed the warranty period.
Here are five relatively good methods that can save most of these "starved" batteries. Note that it is mostly not 100%.
1. Series method. On the entire set of batteries, connect an additional 12V battery with the normal voltage. For example, if the original vehicle has a 48V-20AH battery, we will connect another 12V-20AH battery. A fully charged 12V battery has a voltage of about 13V, and when connected, it can increase the voltage of the entire set of batteries. Then use the original charger to charge it. In this way, the electricity can be charged in. After plugging in the charger, the charger is a green light. At this time, you can charge the battery in. Wait until the charger turns to a green light, then remove the additional connected battery. Then, normal charging can be done.
2. Parallel method. This method is a little more troublesome. For example, the vehicle originally has a 48V-20AH battery. We connect another set of 48V-20AH batteries. As everyone knows, in a parallel circuit, the voltage at each point is equal. The high voltage end will flow to the low voltage end. This is also the method used by many battery dealers to detect batteries that have no power. Then charging can also achieve the charging purpose. This principle is similar to the first method. It is to bring the charging voltage closer to the voltage at both ends of the battery.
3. Low-voltage charging method. Use a smaller model charger for charging. For example, if the battery group is 60V-20AH, then we use a 48V-20AH charger for charging. In most cases, it can also be charged in. The principle is similar to the first method. It is to bring the charging voltage closer to the voltage at both ends of the battery.
4. Single battery charging method. Use a 12V motorcycle charger to charge a single battery. This can activate the battery, but this charging is relatively slow. It usually takes more than 7 hours for the battery voltage to slowly rise to around 12V. If charging all single batteries, it will be very time-consuming.
5. Special charger method. Tianeng charger can automatically recognize the battery voltage. No matter what the voltage of the entire set of batteries is, it can automatically recognize the voltage and charge it. For example, if the original vehicle has a 60V-20AH battery, and now it is less than 30V, it can still charge it. As the voltage increases, it will adapt to a higher voltage level and then charge the battery again. Taiying, Greenjia electric bikes, and Jinpeng tricycles are equipped with this brand of chargers.

    Let me explain how to activate a lithium battery that has "starved to death". This applies to laptop batteries or mobile phone batteries.
The process of activating a battery is called "power scale calibration" in Lenovo's power management software. When using Everest to test the power supply on a PC, there is a "design capacity" and immediately following it is "fully charged capacity". If the values of these two are the same, then the "battery depletion" item at the bottom will show 0%. Generally, batteries that are newly manufactured or have been left unused for a long time without proper maintenance will have a "fully charged capacity" that is less than the "design capacity". At this point, you will see that the "battery depletion" is 1%. This means that the battery is not fully charged and we need to perform a "full charge and discharge" (fully discharging and then charging continuously for 12 hours or more) to fully "develop" the battery's "potential". This process of full charge and discharge is called "activating the battery", and the power management software of Thinkpad and other products has a "power scale calibration" function, which is similar in principle.
Personally, I think some old technologies' batteries, such as NiMH, need to be activated. The theory of lithium batteries is that they need to be activated because they need to form a layer of SEI protection on the negative electrode. However, this process has actually been completed during the production and testing stages. Personally, I think the consumer's misunderstandings of batteries have caused such services.
If your mobile phone battery is "starved to death" and cannot be powered on or charged, then it needs to be activated! First, "starvation" means that the battery is constantly without power or has very low power, resulting in the battery being unable to be charged anymore. Then "activation" currently has two methods: one is to use a universal charger to charge for about 20 minutes, which can activate it. The second is to bring the phone to a repair shop with a more professional voltage (such as 12 volts) to activate it. Specifically, place the power supply's positive and negative poles on the battery's positive and negative poles for a few seconds or even minutes to give it a complete power supply, and connect it! Finally, after activation, it can be used for charging as before, but it is not known whether this will have a significant impact on the battery's lifespan.