Lead acid battery electric vehicles can also be charged quickly? 3a and 10A charging comparison test

Lead acid battery has a long history and mature technology. The only short board is heavy weight, low energy density and slow charging. The first two are not a problem for two wheeled electric vehicle users and can be accepted by everyone. The biggest headache is that the charging is slow. A group of 60v20ah batteries can be charged with an ordinary 2-3a charger in 9-10 hours. One charge is all night.

If it's used well at ordinary times, it's very urgent to go out suddenly. So the question is, can you increase the charging speed? The answer is yes. 10A high current chargers have appeared on the market. Their working current is generally about 7 ~ 10A. The charging current is 2 ~ 3 times that of the ordinary original chargers. They can indeed run 3 ~ 5km in ten minutes.

A set of 60v20ah batteries can be charged with 10A charger in 2 hours. However, many partners are worried about whether frequent rapid charging will have a negative impact on the lead-acid battery and affect its service life?

In order to study the influence of fast charging on lead-acid battery, a well-known battery laboratory in China specially conducted a continuous charge discharge experiment for half a year. We have prepared two new sets of lead-acid batteries, one simulating normal charger charging (3a) and the other simulating fast charging (10a). The data of the experimental results are as follows:

The green line represents the capacity change of lead-acid battery charged with normal current. The initial capacity is 100%. At the end of the experiment, the battery has undergone 369 charge discharge cycles, and the battery capacity remains 76% of the initial capacity; The red line shows the change of the battery capacity with 10A high current fast charging. After 243 charge and discharge cycles, the battery capacity has fallen to 58% of the initial capacity. It can be seen that the cycle life of the battery after fast charging is greatly reduced.

When the lead-acid battery is charged, lead sulfate reacts with water to produce lead dioxide and sulfuric acid. At the same time, with the electrolysis of water, oxygen and hydrogen are generated. Using fast charging, the electrolytic reaction of water intensifies, the battery loses water and becomes dry, and generates a lot of heat, which will lead to the bulging and deformation of the battery, ranging from battery scrapping to fire and other safety accidents.

When the above experiment is carried out for 200 cycles, the battery monomer is weighed. The normally charged battery is lighter by 12g, while the battery after fast charging is lighter by 28g. The water loss rate of lead-acid battery in fast charging mode is more than twice that of normal charging, resulting in the rapid deterioration of battery performance. Frequent use of fast charging is really easy to damage the battery.

However, there are gains and losses, and there are losses and gains. For friends in the takeout and express industry, they use "time for money". In order to shorten the time, many people use 10A fast charging chargers. After all, a battery is only a few hundred yuan. Even if it takes one year to replace it, the time saved and value generated by fast charging will be worth the ticket price long ago.