LM358 alkaline battery charger circuit diagram

　　There are two different opinions on whether alkaline batteries can be recharged. Some say they can be recharged and the effect is very good. Some say they absolutely cannot be recharged, and the battery instructions indicate the risk of explosion. In fact, alkaline batteries can be recharged, and the number of recharges is generally about 30-50 times.

　　In fact, it is due to the mastery of charging methods that two completely different consequences are caused. First of all, it is beyond doubt that alkaline batteries can be charged. At the same time, the battery instructions all mention that alkaline batteries are not rechargeable and charging may cause explosion. This is also correct, but please note that the wording here is "may" cause explosion. You can also understand it as a self-protection statement of the manufacturer's disclaimer. The key to charging alkaline batteries is temperature. As long as the battery can be charged without high temperature, the charging process can be completed smoothly. The correct charging method requires several points:

　　1. Low current 50MA

　　2. Only charge 1.7V, only discharge 1.3V

　　After some people tried charging practice, they said categorically that they could not charge. The reasons for the problems such as failure to charge, short power consumption time, leakage, explosion, etc. are mostly problems with the charger. If the charging current of the charger is too large, far exceeding 50ma, such as some fast chargers with a charging current of more than 200ma, the direct consequence is that the battery temperature is very high and it is hot to the touch. At the very least, it will leak, and at the worst, it will explode.

　　Some people use NiMH rechargeable battery chargers to charge. Low-grade chargers do not have an automatic stop function. Long-term charging will cause the battery to overcharge and leak and explode. Better chargers have an automatic stop function, but the stop voltage is generally set to 1.42V for NiMH rechargeable batteries, while the full voltage of alkaline batteries is about 1.7V. Therefore, the voltage is too low, and it feels like the battery cannot be charged, the power usage time is short, and there is no effect. Another thing is that the battery should not be fully discharged, which means that you should not wait until the battery is completely discharged before charging. In this way, even the best battery can only be charged three or five times, and the effect is poor.

　　It is generally recommended that the voltage of Nanfu alkaline batteries should not be lower than 1.3V. Therefore, if you plan to charge alkaline batteries, you must have a qualified charger with a charging current of about 50ma and a charging cut-off voltage of about 1.7V. Take a look at your charger.

　　There are special chargers for alkaline batteries on the market, so-called patented products. In fact, it is a simple circuit with a charging voltage of 1.7V and a current of 50ma. Using the existing parts LM358 and TL431, I made a simple circuit with a cut-off voltage of 1.67V and automatic stop charging. The cost is only two yuan. For reference for friends who are interested.

　　Related Notes:

　　Alkaline manganese rechargeable battery: It is developed on the basis of alkaline zinc manganese battery. It is also called mercury-free alkaline manganese battery because it uses mercury-free zinc powder and new additives. This battery can be charged and used dozens to hundreds of times without changing the discharge characteristics of the original alkaline battery, which is more economical.

　　Alkaline zinc-manganese battery, also known as alkaline manganese battery, was successfully developed in 1882, developed in 1912, and put into production in 1949. People found that when KOH electrolyte solution was used instead of NH4Cl as electrolyte, there were significant changes in both electrolyte and structure, and the specific energy and discharge current of the battery could be significantly improved.

　　Its features:

　　1. The open circuit voltage is 1.5V;

　　2. The operating temperature range is between -20℃ and 60℃, which is suitable for use in high-cold areas;

　　3. The capacity of large current continuous discharge is about 5 times that of acid zinc-manganese battery;

　　4. Its low temperature discharge performance is also very good.

　　The number of charging times is within 30, generally 10-20 times, and a special charger is required, and it is very easy to lose the charging ability.