Battery capacity calculation method
The capacity of the battery must be the capacity that can be provided to the load at the specified voltage and time. The following describes the capacity calculation method:
1. The necessary conditions for calculating the capacity
A, discharge current
It is necessary to be clear The increase or decrease of the load current during the discharging process and its changes over time.
B. Discharge time
The maximum load time that can be expected.
C, the lowest battery temperature
Pre-estimate the temperature conditions of the storage location of the battery and determine the lowest value of the battery temperature.
It is generally 50C when installed indoors, and -50C when installed indoors in particularly cold areas. When air conditioning is used to ensure the indoor temperature, the actual temperature shall be regarded as the lowest temperature.
D, the lowest allowable voltage
The lowest allowable voltage per cell (V/single cell) u003d (the lowest voltage allowed by the load + the voltage loss of the conductor)/the number of cells in series
2. Calculation formula of capacity
Cu003d1*[K1I1+K2 (I2-I1),,,,,,, KN (IN-IN-1)]/ L
C: 250C rated discharge rate converted capacity (AH), UXL battery is 10HR capacity.
L: The correction value used for capacity changes caused by changes in maintenance coefficients, service years, and service conditions. Generally, the value of L is 0.8.
K: The capacity conversion time determined by the discharge time T, the minimum use temperature of the battery, and the minimum allowable voltage.
I: Discharge current
Subscripts 1, 2,,,, N: Add to T, K, I in the order of discharge current change
3 , Calculation example of capacity
A, discharge current 140A (definite)
B, discharge time 30 minutes
C, minimum battery temperature -550C D, allow The lowest voltage of 1.6V/single cell
According to the above conditions, Ku003d1.1
Cu003d1X1.1X140u003d192(AH/10HR)/0.8 Therefore, UXL220 can be used -2.
Note: The above example is a simple load type battery capacity calculation for a certain discharge current.
The amount of electricity or the length of discharge time that a battery discharges under specified conditions (including discharge intensity, discharge current and discharge termination voltage) is called battery capacity, and the unit is A·h or A·min. The car battery is a reversible DC power source that can convert chemical energy into electrical energy and electrical energy into chemical energy. It is connected in parallel with a generator.
During starting the engine, it supplies power to the starting system and the ignition system.
When the engine is stopped or running at low idling speed, it supplies power to the car's electrical equipment.
When the electricity demand exceeds the output of the charging system, it will provide current for a limited period of time.
The battery also absorbs the instantaneous overvoltage in the circuit to keep the voltage of the automotive electrical system stable and protect the electronic components.
If the battery is not used for a long time, it will slowly discharge by itself until it is scrapped. Therefore, the car should be started at regular intervals to charge the battery. Another way is to unplug the two electrodes from the battery. Note that the positive and negative electrode wires must be unplugged from the electrode column. The negative wire must be unplugged first, or the connection between the negative electrode and the chassis of the car must be unplugged. Then unplug the other end with the positive sign (+). The battery has a certain service life and needs to be replaced after a certain period of time. The above sequence should also be followed when replacing, but when connecting the electrode wires, the sequence is exactly the opposite, first connect the positive electrode, then the negative electrode.
When the ammeter pointer shows that the battery is insufficient, charge it in time. The storage capacity of the battery can be reflected on the dashboard. Sometimes it is found that the battery is not enough on the road, and the engine cannot be started. As a temporary measure, you can ask other vehicles for help. Use the batteries on their vehicles to start the vehicle. Connect the negative and negative electrodes of the two batteries, and the positive and positive electrodes. .
The density of the electrolyte should be adjusted accordingly in accordance with the standards in different regions and different seasons.
When the electrolyte is depleted, distilled water or special replenishment and nano-carbon sol battery activator should be added. Never use pure drinking water instead. Because the purified water contains a variety of trace elements, it will cause adverse effects on the battery.
When starting the car, uninterrupted use of the starter will cause the battery to be damaged due to over-discharge. The correct way to use it is that the total time to start the car each time is no more than 5 seconds, and the interval between restarts is no less than 15 seconds. In the case that the car still fails to start after multiple starts, the reason should be found from other aspects such as the circuit, ignition coil or oil circuit.