【 Weak current College 】 battery discharge test 】

(1) discharge test of necessity

Discharge test, also known as check battery remaining capacity of the test. Especially after using VRLA batteries, whether you need a larger, controversy. We understand that some foreign countries of DC system design both electric power, aerospace and telecommunications sectors have discharge test circuit. China's telecommunications system for valve control battery operation experience and commissioning times than rich and early power systems, also has provisions for periodic discharge test.

VRLA batteries due to the relatively high proportion of acid and the floating charge voltage is quite high, resulting in a plate of corrosion rate may be higher than non-valve regulated lead acid batteries. In addition, VRLA batteries of moisture loss although smaller, but still lost to evaporation, but not after and add water as ordinary batteries. Considering the plate corrosion and water evaporation is the battery life of two main factors, therefore, VRLA batteries for float operation life would be possible to shorten. Of course, there is only the possibility of speaking it.

In addition, due to the manufacturing process for standard control, grid materials weight, pasted layer thickness unevenness, additives harmful impurity too much, and so on factors will result in the individual behind the battery self-discharge rate too high, and thus affect the battery's life. This shows that regular check battery remaining capacity on VRLA batteries is meaningful. From another perspective, through the discharge test can detect battery remaining capacity, you can restore individual behind the battery capacity, to achieve lower battery voltage deviation value. Thus, on VRLA batteries, test the necessity of remaining capacity is greater than the acid-lead-acid batteries, preferably every year to the second.

(2) discharge test criteria matching of discharge is intended to check the floating charge run battery remaining capacity.

VRLA battery discharge voltage if greater than 1.80V/, it greater than 80% of capacity on C10, namely that the remaining battery capacity greater than 80% C10, can continue to run online. Namely: to 0.1I10A of discharge current of 8 hours of continuous discharge, its voltage greater than 1.80V/a, you can stop discharge test, there is no need for 100% of the deep discharge.

Discharge method there are two kinds of resistance discharge method and feedback discharge method.

(1) resistance discharge method

Resistors discharge method used by resistance there is water resistance and two solid resistance.

Water resistance though simple equipment, water and water tanks and salt, but each time the discharge, the operation is more complex, high-current continuous discharge difficult, generally only in the medium and small-capacity battery circuit.

But a group of dedicated persistent high current solid state discharge resistor, its volume is not small, the device is also simplified, simple to use resistance wire even high-power lamp series-parallel composition, plus some pressure regulator, ampere meter, etc. But discharge test should not be left unattended.

(2) feedback discharge method feedback discharge method, as early as the 1970s domestic already have this product, the use of Inverter circuit controlled rectifier, discharge energy back into the AC power system. But because of the quality of products, the products for decades, very few people use.