How to Test Alkaline Battery and Rechargeable Battery Using Tip

by cbattery L. Web Designer

The new Ni-MH AA batteries internal resistance in the 30mΩ typical to 100mΩ, the internal resistance of alkaline batteries typically 200mΩ to 300mΩ (based on state of charge, up to 700mΩ), failure of rechargeable batteries have very high resistance . DS2711/DS2712 by detecting the battery voltage (VP1 and VP2) and set the charge current can be calculated to be charging the battery internal resistance.

CTST pin (used for battery testing, set the threshold) to control the battery's internal measurements. VCTST is the process of charging the battery charge current when the voltage is no less open-circuit battery voltage (OCV) after the difference. This value is equal to the resistance of the battery charging current multiplied by the product. If the sense dell vostro 1500 battery pins (VP1, VP2, and VN1) and the battery did not use the Kelvin connection lead resistance will also be included in the measurement, the impact VCTST. Formula for calculating the external resistor RCTST as: RCTST = 8000 [V ² / A] / VCTST, where VCTST = ICharge × RCELL (type 2)

For example, when a C / 2 rate (1.1A) for the 2200mAh NiMH battery, select RCELL = 150mΩ for the battery internal resistance threshold, VCTST will: VCTEST = ICHARGE × RCELL = 1.1A × 150mΩ = 0.165V
Or: RCTST = 8000 [V ² / A] / 0.165V = 48,485 Ω
(The nearest standard 1% resistance to 48.7kΩ)

If more than VCTST threshold (in this case> 0.165V), indicating that the battery's internal resistance and lead resistance and higher than 150mΩ, the chip will provide instructions or a logical error message indicates (LED1, LED2), and stop the charging process.

Single lithium-ion battery Quick Charger

Because it does not detect the DSC-F505 battery voltage change rate (dV / dt), lithium-ion battery charger than Ni-MH battery simple. Also, because the lithium-ion batteries are very sensitive to overcharging, the charger requires a precise 4.2V ± 50mV to ensure constant current charging power. The nickel-metal hydride battery, charger not only needs voltage monitoring, but also other monitoring (temperature, time, etc.).

MAX8601 single lithium-ion battery charger built-called VBATT controlled voltage source, it can provide at +25 ° C 4.2V ± 0.021V, or at 40 ° C <T <85 ° C to provide 4.2V ± 0.034V precision . When connected via VBATT to lithium-ion battery, the charger can maintain a constant output current (Figure 5), the external resistor (connected SETI pin) and the external capacitance (CT pin connection) can set the charge current and the internal timing. The charger has a negative temperature coefficient of resistance by to monitor the battery temperature.

The main advantage MAX8601 charger is an external adapter or USB port to charge the battery (Figure 6). USB port can be set according to USEL pin provides 100mA, 500mA current (typical USB output current). The chip will automatically select the external power supply (mains adapter or USB). If two power supplies exist, it will choose the host adapter for charging coolpix s3000 charger. Any power must be able to provide a minimum voltage of 4.5V. Charge through the USB port can reduce the cost of an external power supply module, power module is usually larger and less efficient.

MAX8601 has a low battery voltage pre-charge, limited voltage / current limiting rapid charge and float mode control algorithm to optimize the lithium-ion batteries. Additionally, there are power-on reset and battery over-voltage, high / low temperature detection and charging time of continuous monitoring. Overvoltage during charging, high or low temperatures may cause permanent damage to the battery, reducing battery capacity and the use of time, even the battery scrap. The worst case, can cause battery leakage or explosion. MAX8601 to ensure that the process of charging damage does not occur, resulting in longer battery life, eliminating the potentially dangerous situation. DS2711/DS2712 and MAX8601 are stand-alone chargers, they have a variety of monitoring powershot sd200 battery functions (voltage, power, temperature, time, etc.), does not need to monitor the microcontroller does not need power surge protection, and provide clear, simple external switch.

1 can use Ni-MH Ni-Cd battery charger to charge the battery?
A: barely. Because different rechargeable batteries have different turn-off characteristics of nickel-cadmium batteries in the dV / dt = 0 shut off, and nickel-metal hydride batteries in the dV / dt <0 shut off.

(2) whether the same equipment installed in a different capacity, rechargeable batteries, or new and old pavilion zd7000 batteries together?
A: Yes, but not recommended. Because the device's performance will be determined by the weakest battery.

3 what the occasion is not suitable for use rechargeable batteries?
A: Do not smoke, such as remote control and alarm applications such as rechargeable batteries. Because these applications, low power requirements, and the device does not often use. Rechargeable batteries have a higher than normal battery self-discharge rate. For example, Ni-MH batteries lose 1% of electricity per day. So it's not too long working hours.

4 whether to disposable batteries (such as alkaline batteries) charge?
A: No to alkaline batteries. Alkaline batteries are not suitable for chemical composition and structure for charging, the energy will join a strong heat, with the internal temperature rises, the battery will usually leak phenomenon, sometimes explosive. Toxic substances inside the battery a great impact on the environment.

5 Why monitor the temperature of the battery charge is very important?
A: While charging the battery chemical composition and structure suitable for charging, but the battery capacity and charging rate allowed is restricted. Short period of time filled with too much power will the internal temperature, with alkaline batteries, the battery may cause leakage or explosion. Once the battery is fully charged, the battery will charge extra heat. If no temperature monitoring, and reduce the charging rate or stop the pavilion zd8000 battery charge, may produce the same damage on the environment. This is DS2711/DS2712/MAX8601 monitoring in the process of charging the reason why many parameters, which will ensure a long battery life and security of the charging process.