Watt hours and milliamp hours cannot be converted directly because they are also related to voltage, but there is a conversion relationship between watt hours (Wh) and milliamps (amh).
The details are as follows: Wh is a quantity directly proportional to voltage, current and time. mAh is generally used as an indicator of battery charge and discharge. It is an indicator directly proportional to current and time. Well, to make the two values comparable, you need to know the link between mAh and Wh: the voltage.
To keep it simple, you can use this conversion formula to relate the two values: Wh=mAh/1000×voltage. amh=Wh/voltage*1000. For example, a cell phone lithium-ion battery has a nominal voltage of 3.7 V and a capacity of 2000 mAh. When converted to watt hours, it equals 0.54 Wh.
Detailed information:
Factors affecting battery capacity
(1) The effect of discharge rate on battery capacity
The capacity of lead-acid batteries decreases as the discharge rate increases. In other words, the higher the discharge current, the lower the calculated capacity of the battery. For example, a 10 Ah battery can be discharged for 2 hours at 5 A, or 5 × 2 = 10; it can then only discharge 47.4 minutes, or 0.79 hours, when discharged at 10 A. Its capacity is only 10 × 0.79 = 7.9 amp-hours. So, for a given battery discharged at different rates, it will have different capacities. When we talk about capacity, we need to know the hourly rate or discharge rate. To put it simply, it means the amount of current used to discharge.
(2) The impact of temperature on battery capacity
Temperature has a greater impacton the capacity of lead-acid batteries. Generally, as the temperature decreases, the capacity decreases. The relationship between capacitance and temperature is as follows:
Ct1= Ct2/1+k(t1-t2), t1t2 are the electrolyte temperatures respectively. k is the capacity temperature coefficient, Ct1 is the capacity (Ah) when the temperature is t1, Ct2 is the capacity (Ah) when the temperature is t2 In battery production standards, a temperature is generally specified as the standard temperature nominal. , for example, t1 is specified as the actual temperature, t2 is the standard temperature (usually 25 degrees Celsius). The negative plate is more sensitive to the influence of low temperature than the positive plate.
As the temperature of the electrolyte decreases, the viscosity of the electrolyte increases, the ions are subjected to greater resistance, the diffusion capacity decreases, and the resistance of the electrolyte also increases.ent, which increases resistance to electrochemical reaction and some lead sulfates cannot function normally. The charge acceptance capacity decreases, resulting in a decrease in battery capacity.
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Baidu Encyclopedia - Milliwatt hoursReference documents: < /p>Baidu Encyclopedia-Battery Capacity
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