How to Prolong Electric vehicle battery life

Lead-acid battery works Principle
 
Lead-acid battery charging and discharging of the electrochemical reaction process is the process of charging, lead sulfate to form lead oxide, lead oxide and reduction of discharge of lead sulfate. The lead sulfate crystals is a very easy matter, when the battery electrolytic solution of sulfuric acid in the concentration of lead in the static idle time is too high or too long, they will "hold a" group, to form small crystals, and attract around these small crystals lead sulfate, as the inertia of the formation of large snowball as the crystallization of lead sulfate crystals after the charge not only can not be reduced to lead oxide, but also precipitated the board attached to the electrode, resulting in a decline in working area of electrodes, this phenomenon is called sulfide, which is often said that the aging. At this time the battery capacity will gradually decrease until unusable.

Special working environment of electric bicycles

As long as lead acid batteries are used in the curing process, but other than the field of lead-acid battery electric bicycle with lead-acid batteries used on a longer life, it is because lead-acid battery electric bicycle has an easy cure work environment.

① depth of discharge
Used lead-acid batteries in the car when the one-way only in the discharge ignition, ignition battery automatically charged after the generator will not cause the battery depth of discharge. The electric bicycle can not be charged when riding, often more than 60% of the depth of discharge, deep discharge, lead sulfate concentration, sulfide would be very serious.

② large current discharge
Current electric vehicles is generally 20 km cruise 4A, this value is higher than other areas of the battery current, while speeding the work overload of the current electric cars is even greater. Battery manufacturers have been 1C charge 70%, 2C 60% of the discharge cycle life test. After such a life test can be achieved 350 charge and discharge cycle life of the battery a lot, but the actual effect will be far in the use of the. This is because the large current increase of 50% of the work of depth of discharge, the HP EliteBook 6930p Battery will accelerate curing. Therefore, the electric three-wheeled motorcycle shorter battery life because the body is too heavy three-wheeled motorcycle, working current up to 6A above.

③ high frequency discharge
Used in the field of battery backup power supply, and only during power outages will discharge, if the stop 8 times a year electricity to reach 10 years of life, only done 80 cycles charge life, and electric vehicle charge and discharge cycles a year 300 times or more are common.

④ Short Charge
Since electric bicycles are vehicles, not much time to charge, to be completed within 8 hours of 36 volt or 48 volt rechargeable 20 Ah, this must raise the charging voltage (typically 2.7 to 2.9 V single-Festival), when the charge single-cell voltage exceeds the voltage of oxygen evolution (2.35 V) or hydrogen-voltage (2.42 V), the battery will be open due to excessive oxygen evolution and the exhaust valve, causing water loss, so that the electrolyte concentration increased, the phenomenon of increasing sulfide battery .

⑤ charge after discharge can not be timely
As a transport, charging and discharging of electric bicycles are completely separated from the difficult conditions in a timely manner after discharge charge, and discharge of lead sulfate formed after a large number of hours without charge if more than half reduced to lead oxide, sulfide will form crystals .

The Charging Equipment

Widely circulated saying the industry is: the battery is not worn, it is a bad charge. In order to meet short-term electric bicycle high-capacity rechargeable battery, charging in the three-constant voltage current limit, had to constant pressure by increasing the value to 2.47V ~ 2.49V. In this way, much higher than the battery voltage of oxygen evolution at the positive plate and negative plate hydrogen evolution voltage. Some charger manufacturers of products in order to reduce the charging time of instructions, improved float switch current constant pressure, and making full power after charging indicator, there is no full power to compensate by increasing the float voltage. Thus, many of the charger float voltage than single-cell voltage 2.35V, so that a large number of oxygen evolution is still floating stage. The battery in poor oxygen circulation, so that the exhaust are constantly floating stage. High constant value to ensure that the charging time, but the sacrifice is the water loss and cure. Low constant value, and charge into the battery charging time is difficult to guarantee. The battery in improving battery grid alloy to improve the analysis of gas potential, improve oxygen circulation performance, improve the efficiency of sealed response based on the control of the maximum charging voltage 2.42V charging less, that is, hydrogen evolution potential in the following. This will inevitably lead to the extension of the charging time, which must be charged in the high current (limiting charge) of the state, adding to the polarization of the negative pulse, to improve the battery's charge acceptance in the high current charging more than filled the time Some power and reduces the charging time. 70% of the 2C charging current, battery charge acceptance is relatively large when using large current charging the HP Compaq Business Notebook 6535b Battery, damage to the battery is relatively small. Basically, the battery voltage is not higher than that of a serious hydrogen evolution. Once above the hydrogen evolution voltage, the battery will be fast water loss. The use of such chargers, must be a continuous charge and discharge a few days if the half-way stop charging, the battery will have a more serious lapse prematurely curing. And users use the battery, is no guarantee that after each use, are able to charge in time, occur several times within a year the situation is not promptly charged, the battery will be the accumulation of sulfide. Most chargers manufacturers say the depot because of the price factor does not accept the charger can guarantee the battery life. Admittedly, this is most small businesses is the case, however, for development, the scale of the large companies do not buy the expensive good charger. Some charger manufacturers to exaggerate certain features, not the effectiveness of its promotional products as well. There are many features to sell the concept of function, effectiveness is limited.

Other reasons
Many cells in the single test, it can get good results, but the battery pack for the thread, because of capacity, the open circuit voltage, state of charge, curing varying degrees, the difference will be in series with the battery pack is expanded, a single experience of the poor state of the entire group of batteries, their life significantly decreased. Cong charge the battery in the production line, to the user with car after car use this time to go through many Huanjie interval of time or even for months, in this period, as not to supplement the battery power, resulting from the discharge of lead sulfate large accumulation of crystals, the user just bought a new battery may have been reported to charge the battery and even aging. When the battery manufacturers in the implementation of quality assurance, on the recovery of the battery is not completely eliminated. After back to back the battery, the battery manufacturer to re-charge and discharge test, the test often found in more than 60% of single cells is inconsistent with the conditions of the batteries back to back. The reason for that is in series with the battery pack, the individual behind the formation of the entire set of battery cells function decline caused by the whole group back to back. Many battery manufacturers to take back to back with the battery group, pay, in addition to sulfur, packaging, again available to users to increase the effective battery life, reduce scrap, reduce some of the battery manufacturer's claim for loss of management Therefore, many dealers have already felt the battery was provided by the manufacturer, "Generations." Electric vehicle HP Compaq 6735b Battery when used properly, the general problem of the battery is not used for 3 years or so, on the contrary, greatly reduce the service life is short. Therefore, consumers daily maintenance of electric vehicle batteries electric car battery life is to determine the key.