How to judge and measure the battery capacity of electric vehicle

1, Use voltmeter and load it to test the battery capacity

How to judge electric vehicle battery capacity? Test battery capacity, voltage of only using a voltmeter or multi-meter block without load to check whether the battery capacity is enough, it is difficult to accurately. Just measure the voltage, the current consumption is few, so will have big pressure drop inside the battery, so according to the voltage is not low, but with quite a load, such as open headlight (load current 10 ~ 15 a), the horn (load current 6 ~ 12 a), the battery will dim the lights, horn husky, which shows a lack of electricity.

2, with a hydrometer test battery capacity

Is also a kind of commonly used methods, generally charged battery electrolyte in 20 ℃ standard proportion is 1.25 ~ 1.29 kg/L; If the battery at 20 ℃ electrolyte specific gravity is less than the value, is greater than 1.06 kg/L battery storage battery is low, need to recharge; If the battery at 20 ℃ electrolyte specific gravity of 1.06 kg/L or less means that the battery has been completely discharge or damage. According to this principle, the use of balance to measure the proportion of battery electrolyte can know battery capacity, also can further determine the condition of the battery.

3, battery tester test battery capacity

In the daily maintenance and repair can really rapidly and accurately detect how much battery capacity, or to use the battery tester. When using the battery monitor access to the battery 10 ~ 15 seconds, keep the voltage at 10.5 ~ 11.6 V, said capacity is enough, battery trouble-free; Keep the voltage at 9.6 V ~ 10.5 V, said capacity is insufficient, battery trouble-free; Voltage has dropped below 9.6 V, said a serious shortage of capacity or the battery failure.

The above is the testing methods of electric vehicle battery capacity, as long as everyone carefully according to the several method can detect the electric vehicle battery capacity. In addition if you select the "Kang Yang graphene battery not gold", the capacity will be more, more durable

Electric vehicle battery capacity measurement method:

Battery capacity test is usually under the condition of 25 ℃ with constant current discharge to protect voltage, discharge time and discharge current multiplication is the capacity of the battery.

Battery capacity when the unit is (AH), with different discharge current measurement result is different, according to the national standard, the electric battery capacity rate calculation in 2 hours. With the capacity of the battery is C, for example, in 0.5 C constant current discharge, the discharge end of the time.

Now most of lead-acid batteries and electric vehicle for lead-acid battery is of low cost, high cost performance. The battery is unique, when the battery use after a period of time to make the voltage drop, can give it to reverse current, make the battery voltage. The battery can charge, can be repeatedly used, so called it "lead-acid battery".

1, No matter which kind of battery capacity measurement is it needs to be discharge detection.

2, each cell has a maximum charging voltage and a minimum discharge voltage. Discharge detection is the process from the high voltage discharge to the minimum voltage.(the two voltage values each box has a instructions when opening the battery, I will not repeat the)

3, the same battery, choose different discharge rates, its power will be different.(commonly used have 1/2 c discharge rate; A quarter of c;1/5 c;1/10 C) represents the battery rated capacity., of course, the smaller the discharge rate, the test results more accurate, and the smaller the cell damage, but also more time consuming.

4, discharge time depends on you choose the discharge rate. For example: 1/2 c discharge two hours for qualified, 1/4 c discharge four hours for qualified...1/10 c discharge 10 hours.

5, discharge protection: if it with all the problem you don't have to worry about, put all itself with over discharge protection function. If the tungsten filament or discharge resistor is discharge to discharge that is about to be careful, it is best to from already do a low voltage protection circuit. If you don't understand, that is on the battery in parallel a voltmeter, always have a look. Don't forget, in the morning in the afternoon it was ended.

6, the last point is about power, in theory, with 1/2 c discharge in two hours, 1/10 c discharge 10 hours. But in reality to 1/2 c discharge with most of them are less than 120 minutes, and, in turn, 1/10 c discharge has more than 600 minutes. So more than the first kind of circumstance is not low for 110 minutes can be treated as the normal range.

Battery capacity is generally through the discharge test, special equipment. If not, replace it by tungsten. First check the battery capacity, for example: 10 ah12ah14ah17ah18ah20ah. These are what we usually use. After connecting the battery in series, adjust the length of the tungsten wire, measure the current. Control the current based on the capacity value. Then check the discharge time. If it has one hour, it will be OK. Single battery cannot be lower than 10.5 V. Batteries discharging together should have consistent voltage. If there is a deviation on these batteries, it means that the battery is not good. There is no need to use large current on general test, which needs to be about 5-7 A, and the time should be more than one hour.

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