Battery charging problems . I will discuss most common failure examples and suggest some troubleshooting steps. Example 1. Laptop shuts off when AC adapter unplugged. When you move the cursor arrow over the battery icon while the laptop is connected to AC adapter, it show the remaining charge and says “charging”. The power meter utility (if available) also shows that battery is connected and charging. But. The battery not seated correctly. Try reconnecting it. The battery contacts got dirty or oxidized and it’s not making good connection with the motherboard. Apply some electronic contact cleaner on the contacts. If reconnecting the battery doesn’t help, most likely it’s bad and has to be replaced. If you replaced the battery but the problem still exists, this is motherboard related failure. Apparently the charging circuit on the motherboard failed. In this case the whole motherboard has to be replaced (or repaired on the component level). Example 2. The battery not detected by the laptop. There is a red cross on the battery icon. If you move the cursor arrow over the battery icon, it says “no battery detected”. Possible problems: 1. Most likely the battery is bad. You have a very good chance to fix this problem by replacing it with a new one. If replacing the battery doesn’t help, this is motherboard related failure. The motherboard has to be replaced (or repaired on component level). Example 3. The battery discharges very quickly after it reaches some critical point. The battery detected by the laptop and charges properly to 1. When you unplug the AC adapter, it take normal time to discharge until some critical point (let’s say 8. Possible problems: This is battery failed. It has to be replaced with a new one. Example 4. The battery charges only if the power plug positioned correctly. You have to wiggle the power plug in order to charge the battery. After you find the right position, it charges properly. Possible problems: 1. 298 The new Surface Pro: new processors, boosted battery life and more.![]() On Tuesday, the TSA announced a pilot program using new biometric technology to replace boarding passes and IDs with quick fingerprint scans. Apple is making changes to the way apps get information about users’ location and photos, giving users more control over what data they share and when they share it. What can File Undelete do? Recover deleted or lost files even if emptied from the Recycle Bin File recovery after accidental format, even if you have reinstalled. AC adapter failure. The AC adapter power cable is damaged. Here’s how to test your AC adapter. If the AC adapter works fine, most likely this is power jack (connector where you plug power adapter) failure. In this case the power jack has to be replaced. ![]() How to Prolong Lithium- based Batteries. Discover what causes Li- ion to age and what the battery user can do to prolong its life. Battery research is focusing on lithium chemistries so much that one could imagine that the battery future lies solely in lithium. ![]() There are good reasons to be optimistic as lithium- ion is, in many ways, superior to other chemistries. Applications are growing and are encroaching into markets that previously were solidly held by lead acid, such as standby and load leveling. Many satellites are also powered by Li- ion. Lithium- ion has not yet fully matured and is still improving. Notable advancements have been made in longevity and safety while the capacity is increasing incrementally. Today, Li- ion meets the expectations of most consumer devices but applications for the EV need further development before this power source will become the accepted norm. ![]() ![]() In theory such a mechanism should work forever, but cycling, elevated temperature and aging decrease the performance over time. Manufacturers take a conservative approach and specify the life of Li- ion in most consumer products as being between 3. Evaluating battery life on counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a cycle (see BU- 5. Basics About Discharging). In lieu of cycle count, some device manufacturers suggest battery replacement on a date stamp, but this method does not take usage into account. A battery may fail within the allotted time due to heavy use or unfavorable temperature conditions; however, most packs last considerably longer than what the stamp indicates. The performance of a battery is measured in capacity, a leading health indicator. Internal resistance and self- discharge also play roles, but these are less significant in predicting the end of battery life with modern Li- ion. Figure 1 illustrates the capacity drop of 1. Li- polymer batteries that have been cycled at a Cadex laboratory. The 1,5. 00m. Ah pouch cells for mobile phones were first charged at a current of 1,5. A (1. C) to 4. 2. V/cell and then allowed to saturate to 0. C (7. 5m. A) as part of the full charge saturation. The batteries were then discharged at 1,5. A to 3. 0. V/cell, and the cycle was repeated. The expected capacity loss of Li- ion batteries was uniform over the delivered 2. Figure 1: Capacity drop as part of cycling. Eleven new Li- ion were tested on a Cadex C7. All packs started at a capacity of 8. The 1. 50. 0m. Ah pouch packs are used in mobile phones. Courtesy of Cadex. Although a battery should deliver 1. In addition, manufacturers tend to overrate their batteries, knowing that very few users will do spot- checks and complain if low. Not having to match single cells in mobile phones and tablets, as is required in multi- cell packs, opens the floodgates for a much broader performance acceptance. Cells with lower capacities may slip through cracks without the consumer knowing. Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (Do. D) determines the cycle count of the battery. The smaller the discharge (low Do. D), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li- ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life. The exception may be a periodic calibration of the fuel gauge on a smart battery or intelligent device. The voltages of lithium iron phosphate and lithium titanate are lower and do not apply to the voltage references given. Note. Tables 2, 3 and 4 indicate general aging trends of common cobalt- based Li- ion batteries on depth- of- discharge, temperature and charge levels, Table 6 further looks at capacity loss when operating within given and discharge bandwidths. The tables do not address ultra- fast charging and high load discharges that will shorten battery life. No all batteries behave the same. Table 2 estimates the number of discharge/charge cycles Li- ion can deliver at various Do. D levels before the battery capacity drops to 7. Do. D constitutes a full charge followed by a discharge to the indicated state- of- charge (So. C) level in the table. Depth of discharge. Discharge cycles(NMC / Li. PO4)Table 2: Cycle life as a function ofdepth of discharge. A partial discharge reduces stress and prolongs battery life, so does a partial charge. Elevated temperature and high currents also affect cycle life. Note: 1. 00% Do. D is a full cycle; 1. Cycling in mid- state- of- charge would have best longevity. A battery dwelling above 3. Exposing the battery to high temperature and dwelling in a full state- of- charge for an extended time can be more stressful than cycling. Table 3 demonstrates capacity loss as a function of temperature and So. C. Temperature. 40% charge. My Dell Inspiron 1545 laptop has stopped showing the power icon in the notification area of Windows 7. It was there and working up until 2 days ago. Found this solution on the LogBlog after another failed Vista boot up. This issue is being referred to as the blacK Screen Of Death (KSOD), and is described as. ![]() ![]() Table 3: Estimated recoverable capacity when storing Li- ion for one year at various temperatures. Elevated temperature hastens permanent capacity loss. Not all Li- ion systems behave the same. For example, a lithium- ion cell charged to 4. V/cell typically delivers 3. If charged to only 4. V/cell, the life can be prolonged to 6. V/cell should deliver 1,2. V/cell should provide 2,4. On the negative side, a lower peak charge voltage reduces the capacity the battery stores. As a simple guideline, every 7. V reduction in charge voltage lowers the overall capacity by 1. Applying the peak charge voltage on a subsequent charge will restore the full capacity. In terms of longevity, the optimal charge voltage is 3. V/cell. Battery experts believe that this threshold eliminates all voltage- related stresses; going lower may not gain further benefits but induce other symptoms. Every 0. 1. 0V drop below 4. V/cell doubles the cycle but holds less capacity. Raising the voltage above 4. V/cell would shorten the life. The readings reflect regular Li- ion charging to 4. V/cell. Guideline: Every 7. V drop in charge voltage lowers the usable capacity by about 1. Note: Partial charging negates the benefit of Li- ion in terms of high specific energy. This allows maximum capacity, because the consumer wants nothing less than optimal runtime. Industry, on the other hand, is more concerned about longevity and may choose lower voltage thresholds. Satellites and electric vehicles are such examples. For safety reasons, many lithium- ions cannot exceed 4. V/cell. Figure 5 demonstrates cycle count as a function of charge voltage. At 4. 3. 5V, the cycle count of a regular Li- ion is cut in half. Figure 5: Effects on cycle life at elevated charge voltages. Higher charge voltages boost capacity but lowers cycle life and compromises safety. Source: Choi et al. The Li- ion charger turns off the charge current and the battery voltage reverts to a more natural level. This is like relaxing the muscles after a strenuous exercise. The largest capacity loss occurs when discharging a fully charged Li- ion to 2. So. C (black); the loss would be higher if fully discharged. Cycling between 8. The smallest capacity loss is attained by charging Li- ion to 7. This, however, does not fully utilize the battery. High voltages and exposure to elevated temperature is said to degrade the battery quicker than cycling under normal condition. Although longer lasting, a less than full cycle does not fully utilize a battery. With a modern Energy Cell, this is 2. Wh/kg, but the cycle life will be compromised. All being linear, the life- prolonging mid- range of 8. Wh/kg to 1. 50. Wh/kg. This is practical because batteries should retain some reserve before charge under normal use. Lab tests often get numbers that are not attainable in the field. The worst situation is keeping a fully charged battery at elevated temperatures. Battery packs do not die suddenly, but the runtime gradually shortens as the capacity fades. Lower charge voltages prolong battery life and electric vehicles and satellites take advantage of this. Similar provisions could also be made for consumer devices, but these are seldom offered; planned obsolescence takes care of this. A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. To make this feature user- friendly, a device should feature a “Long Life” mode that keeps the battery at 4. V/cell and offers a So. C of about 8. 0 percent. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4. V/cell. The question is asked, “Should I disconnect my laptop from the power grid when not in use?” Under normal circumstances this should not be necessary because charging stops when the Li- ion battery is full. A topping charge is only applied when the battery voltage drops to a certain level. Most users do not remove the AC power, and this practice is safe. Modern laptops run cooler than older models and reported fires are fewer. Always keep the airflow unobstructed when running electric devices with air- cooling on a bed or pillow. A cool laptop extends battery life and safeguards the internal components. Energy Cells, which most consumer products have, should be charged at 1. C or less. Avoid so- called ultra- fast chargers that claim to fully charge Li- ion in less than one hour. Last updated 2. 01. Please Read Regarding Comments ***. Comments are intended for . Battery University monitors the comments and understands the importance of expressing perspectives and opinions in a shared forum. However, all communication must be done with the use of appropriate language and the avoidance of spam and discrimination. We recommend posting your question in the comment sections for the Battery University Group (BUG) to share. Or Jump To A Different Article Batteries as Power Source.
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