Digital battery

Overcharging the electrochemical reaction:

 

From the equation to see that the battery overload, precipitation positive plate of oxygen, plaques precipitating negative hydrogen. Due to the hydrogen electrode catalyst for the broader region, and hydrogen can easily spread to the hydrogen electrode surface, therefore, hydrogen and oxygen can easily recombine to form the battery Within the water, so that the gas pressure inside the container remain unchanged, this re-compounded rate quickly, you can make the internal battery of the oxygen concentration does not exceed a few per thousand. Inspiron 5150 battery Inspiron 700m battery

 

From the formula above reaction can be regarded as batteries reaction metal-hydride nickel and nickel-cadmium similar, but the negative charge resulting from the discharge process is different from the latter two reactive can be seen that the Ni - MH can also be done to seal a structure type. Nickel-metal hydride used more KOH electrolyte solution, and add a small amount of LiOH. Vinylon using porous nylon membrane or non-woven fabrics such as nonwovens. To avoid the latter part of the battery charging process pressure is too high, the battery is equipped with an explosion proof.

 

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The Ni-Cd battery charging characteristic curve in Figure 1. When the constant current into the discharge had finished charging the battery because the battery’s internal resistance voltage drop generated, so the battery voltage has increased rapidly (A). Since then, the battery began to accept the charge, the battery voltage to a lower rate continues to rise. In this context (Beach AB), the electrochemical reaction to generate a certain amount of oxygen in the same time as the same rate of oxygen and the chemical combination of hydrogen, therefore the temperature of the battery internal and gas pressure is very low.

 

Process of charging the battery, the compound of oxygen to oxygen is higher than when the battery increases the internal pressure. * The normal pressure inside the battery is about 1 pound force / inch 2. Overload, the rate of charge, the battery internal pressure will soon be in place by the force of 100 pounds / inch 2 or more. Inspiron 9200 battery Inspiron B120 battery

 

Examine a variety of ways of pricing method, the nickel-cadmium batteries produced gas is an important issue. Bubbles gathered at the plate surface of the plate will reduce the surface involved in chemical reactions and increase the resistance of the battery internally. Overload, battery produce much gas, if not rapidly compounds, the internal pressure of the battery would be increased considerably, which would damage the battery. Furthermore, the pressure is too great, the battery sealed play an open porosity, so that the oven electrolyte. If the electrolyte has continued to make holes through the oven, the viscous nature of the electrolyte increases, the transport of ions between the plates becomes difficult if the internal resistance of the battery to increase the capacity decrease. Inspiron B130 battery Latitude D410 battery

 

After some time (c), the electrolyte begins to produce air bubbles, the bubbles gather at the plate surface, so that the effective area of lower plate, so the impedance internal battery increases the battery voltage began to rise rapidly. This is close to an electrical signal accordingly.

 

Sufficient power, the rechargeable battery in the battery current is not converted into energy storage, but in the positive potential of oxygen on-board ultra-generated. Oxygen is due to the electrolyte resulting from electrolysis is not due to return to the cadmium hydroxide, cadmium generated. Potassium hydroxide and water in the composition of the electrolyte, hydrogen and oxygen ions in oxygen, water and free electrons, the formula for reactionLatitude D800 battery Latitude D810 battery

 

4OH-→ O2 ↑ 2 H2O +4 e –

 

Although the oxygen in the electrolyte can quickly produce surface plate negative electrolyte in the composite, but significantly increased the temperature of the battery. In addition, since the charging current used to produce oxygen, thereby increasing the pressure inside the drum.

 

Because a large number of hydroxyl ions from that of a hydroxide of cadmium little easier out of oxygen, so sharp rise in temperature inside the battery so that battery voltage drops. Therefore, the peak battery voltage curve (D points).

 

Electrolyte, the generation of oxygen compounds is an exothermic reaction, battery during overload (point E) and continues to produce oxygen, so that the temperature within the battery and pressure rise. If you force the exhaust causes the electrolyte to reduce battery capacity and damage the battery down. If the gas can be discharged quickly explodes. Latitude X1 battery XPS M2010 battery

 

Using runoff low constant current charging, the batteries have a dendrite. The dendrites can spread through the partition between the plates. In the proliferation of more severe cases, the dendrites will be part or all of the short-circuit the battery.

 

Characteristics of Ni-MH rechargeable batteries, nickel-cadmium is similar to both the voltage during charging, the temperature curve shown in Figure 1-2 and Figure 1-3. As you can see, termination charge, the battery nickel-cadmium voltage drop is much larger than the nickel-metal hydride. When the battery capacity will reach 80% capacity prior to the temperature of nickel-cadmium rises slowly when the battery capacity reaches 90% after the nickel-cadmium will soon rise in temperature before. When the battery is fully charged when the base, NiCd / NiMH battery temperature increase rate in almost the same. Studio 15 battery Studio 17 battery

 

Ni-Cd Ni-MH battery charging principles and practices - the process of pricing and pricing methods, September 23, 2009 Author: Anonymous Source: ATEX Battery Test Lab Editor: Open the process of pricing and pricing methods

The process of loading the battery can generally be divided into pre-charge, fast charge, top-up trickle charge into four stages.

Term Unused long or a new battery, the top one on the use of Fast-charge, it will affect battery life. Therefore, it should be the first with a small current to the battery charging, charging that meet certain conditions, this step is called pre-load.

 

Fast charging is charging high current, fast recovery of the battery power. Fast-loading rate of 1C or more generally the time of fast charging, battery capacity and the loading rate determining. Studio 15 battery Studio 17 battery

To avoid overcharging, the charger uses a number of load current low. The normal charge nickel-cadmium batteries can accept the charge rate of C/10 or less, so the charging time to over 10 hours. The use of current low charge, the battery does not produce too much gas, the battery temperature is too high. As long as the battery charger, receiving the low constant-current battery charger will be able to provide a trickle charge small current. Rechargeable battery with low current, the heat generated within the battery can be dispersed naturally.

 

Problem Charger Trickle main recharges too slowly, for example, with a capacity of 1 Ah battery, using C/10 charge rate, charging time to over 10 hours. In addition, the battery re-apply a fill rate is low, when there is a dendrite. In most loader drip, not to any voltage or control the temperature information, and therefore can not guarantee that the battery is fully charged, immediately after the bifurcation charger. 6Y270 75UYF G5266

 

Fast charge constant current charge and point charge pulse are two types of charge at constant current is a constant current to the load current, the pulse load is the first use of pulsed current to charge the Battery. And then let the battery discharge and so on. Great battery pulse amplitude, width very narrow. Usually discharge pulse amplitude for pulse charging 3 times. Although the amplitude of the pulse discharge and battery capacity related, however, with the ratio of current amplitude load remained unchanged, the pulse load signal load current as shown in Figure 1-4.

 

Charging process, the nickel-cadmium reduced to nickel hydroxide nickel hydroxide, cadmium hydroxide, cadmium restores. During this process, the bubbles generated, gathered at the plate on both sides, so that the effective area of the plate is reduced, so that the plate resistance increases. Since the effective area of smaller plates, the charge in the full time required for increased capacity. HD438 KD186 NF343

 

Join pulse discharge after the bubble left the plate and with the compound negative oxygen on board. This process reduces the depolarization of the internal pressure of the battery temperature and internal resistance. At the same time, most of the charge in the battery is converted into chemical energy rather than gas and heat.

 

Charge-pulse width of discharge should be chosen to ensure the plate to restore the crystalline structure of the original, eliminating the memory effect. Using measurements of depolarization discharge can improve the efficiency of charge and can load current very rapid.

 

Using some quick charge only the right, after the cessation of fast charging, the battery is fully charged. To ensure the refill to 100% of the power, but by adding up the loading process. Complete the charge rate is generally not exceed 0.3c. By completing the charging process, the temperature will continue to increase when the temperature exceeds the limit, the charger into the charge state of maintenance. G1947 RN873 Y6142

 

Store, the nickel-cadmium batteries will power the flow of C/30 at C/50 reduced due to self-discharge the battery to compensate for the loss of electricity to supplement the charge after the end loader runoff should be transferred automatically to the process of electricity. Slow charge, also known as maintenance costs. According to self-discharge of the battery characteristics of stocking slow are generally low. As long as the battery connected to the charger and the charger switched on, in maintaining the state of charge, the charger the battery charging rate will be an additional burden, it will give the battery is fully charged, the state’s total.

 

Fast Control Method of end load

Fast method of charging, the charging current is several times the normal load current. Enough power, if not quickly stop the fast charging, the battery temperature and internal pressure will increase rapidly. The internal pressure is too great, the battery sealed play an open porosity, so that the oven electrolyte, resulting in the viscosity of the electrolyte was increased, and increases resistance to the internal battery, the capacity decrease. GD761 Y9943 FK890

 

Functionality of the battery NiCd fast charge can see that, after fully charged, the battery voltage began to decrease, the battery temperature and internal pressure increases rapidly to ensure that battery is fully charged, but charges can be used time control time control of voltage and temperature control over methods.

(1) Timing Control

1.25C rate charged battery may be sufficient 1h; The loading rate of 2.5 ° C, when used, 30min May suffice. Therefore, according to battery capacity and current load, it is easy to determine the time required for charging. This control approach is the easiest, but since the beginning of the state of battery charge are not identical and some costs to a shortage of batteries, some battery before charging, so that when the loading rate of less than 0.3c only allows the use of this approach. GK479 3R305

 

(2) voltage control

In the method of voltage control, the easiest to detect is the highest voltage of the battery. The method of voltage control commonly used are the following:

Maximum voltage (Vmax) can be seen from the characteristic curve of load, the battery voltage reaches its maximum when the battery is fully charged. Loading process, when the battery voltage reaches the specified value, should immediately stop fast charging. Weaknesses of this control method are: the battery fully charged, the maximum voltage of the ambient temperature, load the pace of change, but every single battery pack the maximum charge pressure is also a difference, so this method may not be very Specifically the battery have sufficient charge. Inspiron 2500 battery Inspiron 3700 battery

 

Negative voltage increment (DELTA-V) due to increased negative battery voltage and the absolute voltage of the battery has nothing to do, but the rate of temperature and no load and other factors so that you can better judge the battery is fully charged. Weaknesses of this control method are: the battery voltage is a negative increment, the battery was charging, so the battery at higher temperatures. In addition, Ni-MH battery is fully charged, the battery voltage to pass through a longer time before a negative increment, the more serious charge. Therefore, this control method applied mainly nickel-cadmium.

 

Voltage and zero-increment (0ΔV) Ni-MH battery charger, to avoid waiting for a negative voltage increment is taking too long and damage the battery, usually 0ΔV control laws. Disadvantage of this approach are fully charged before the battery voltage is within a certain period of time may very few changes, leading to premature termination of fast charge. To this end, at present most of the Ni-MH Battery Quick Charger-0ΔV use of highly sensitive detection, when the battery voltage is slightly lower, the immediate cessation of the fast charge. Inspiron 3800 battery Inspiron 4000 battery

 

(3) temperature control

To avoid damaging the battery, the battery temperature is too low when you can not start fast charging, the battery temperature increases the required values, you must immediately stop fast charging. Methods of temperature control are used:

Maximum temperature (Tmax) during charging, usually when the battery temperature reaches 45 ℃, should immediately stop fast charging. The temperature of the battery can be mounted in conjunction with the battery thermistor to detect. Disadvantage of this approach is the thermistor response time longer, the temperature tests, a lag at the same time, the battery has a maximum operating temperature and environment temperature. When the ambient temperature is too low, adequate power, the battery temperature can be reached 45 ℃. Inspiron 4100 battery Inspiron 4150 battery

 

Elevated temperature (DELTA.T) to eliminate the impact on the environment, the method of temperature control can be used. When cells reach the required temperature rise of the value immediately after the cessation of the fast charge. In order to achieve temperature control, must use two thermistors were used to detect the battery temperature and ambient temperature.

Variation rate of temperature (DELTA.T / Δt) of the nickel hydrogen and nickel-cadmium batteries fully charged, the battery temperature rose rapidly, but increased at a rate of DELTA.T / Δt is basically the same when the temperature rise of the battery 1 ℃ per minute, it should immediately terminate fast charge, this method of load control, widely used in recent years. It should be noted, due to resistance thermistor temperature and the relationship is not linear, therefore, to improve the accuracy of detection should seek to reduce the thermal resistance of nonlinear effects. Inspiron 8000 battery Inspiron 8100 battery

 

The minimum temperature (Tmin) where the battery when the temperature is below 10 ℃, with very fast charging current, it will affect battery life. In this case, the shipper should be transferred automatically to trickle charge until the battery temperature is 10 ℃ after, then transferred to the fast charge.

 

(4) Integrated control

The advantages and disadvantages of different control methods. To ensure that under no circumstances can accurately and reliably control the battery charging, and currently widely used in rapid chargers, including regular monitoring, control voltage and temperature control of a integrated control legislation. Inspiron 8200 battery Latitude C500 battery