Causes and treatment of short-circuit of lead-acid batteries

Aug 13, 2019   Pageview:20

Lead acid battery is the most widely used high-efficiency battery in high-power power supply. In the process of use, short-circuit will be caused due to different reasons, which will affect the use of the entire battery.

 

The main reasons for the short-circuit of lead-acid batteries: the charging current is too large, the charging voltage of a single battery exceeds 2.4 V, there is a short circuit or partial discharge, excessive temperature rise, and valve control failure.

 

Treatment of short-circuit of lead-acid battery: reduce charging current, reduce charging voltage, check whether the safety valve body is blocked. Regular charge and discharge. Many of the lead-acid batteries in the UPS power supply system have been adjusted to the rated voltage at the time of delivery, and the size of the discharge current increases with the increase of the load. The load should be reasonably adjusted during use. For example, the number of stations used to control electronic devices such as computers. In general, the load should not exceed 60 % of the UPS rated load. Within this range, there will be no excessive discharge of the battery. The lead-acid battery storage will lose part of its capacity due to self-discharge. Therefore, before the lead-acid battery is put into use after installation, the remaining capacity of the battery should be judged according to the open circuit voltage of the battery, and then the battery should be recharged by different methods. For standby storage batteries, should be recharged once every 3 months. The battery can be judged by measuring the open voltage of the Panasonic battery.

 

Take a 12V battery as an example. If the open circuit voltage is higher than 12.5 V, it means that the battery storage energy is more than 80 %. If the open circuit voltage is lower than 12.5 V, it should be recharged immediately. If the open-circuit voltage is less than 12V, it means that the battery stores less than 20 % of the electricity and the battery is unusable. When Panasonic battery is short-circuited, its short-circuit current can reach several hundred amps. The stronger the short-circuit contact, the larger the short-circuit current, so all the connection parts will produce a large amount of heat, and the more heat is generated in the weak link, the connection will be melted off, resulting in a short-circuit phenomenon. The local production of explosive gas(or explosive gas stored when charging) may occur in the battery, and sparks will be generated when the connection is broken, which will cause the battery to explode; If the short-circuit time of the battery is short or the current is not particularly large, it may not cause the melting phenomenon at the connection, but the short-circuit will still overheat, which will damage the adhesive around the connection bar and leave it with hidden dangers such as leakage.

 

Therefore, in the process of using lead-acid batteries, we must pay attention to the correct use of the battery, there must be no short circuit. When installing lead-acid batteries, the tools to be used should be insulated. When connecting, first connect the electrical appliances other than the battery. After checking, there is no short circuit. Finally, connect the battery. The wiring specifications should be well insulated to prevent overlapping pressure. rupture. Through these meticulous work, it is possible to better prevent short-circuit of lead-acid batteries, make lead-acid batteries safer to use, and have a longer life.

 

The page contains the contents of the machine translation.