Monthly Archives: January 2013

power adapter

How to pick the right laptop AC adapters

Leave a comment

All new laptops come with AC adapters. Adapters are used for charging laptop batteries and also used to supply power directly. There are occasions which we require to buy an laptop AC adapter. Most laptop users travel, for tdose travel to Europe or CA they require laptop AC adapters that take 100-240 voltage input and output 16 voltage or 19 voltage.
Let us present 3 easy steps to pick the right laptop AC adapters.
1. Finding the right “”tips”” – Different laptops have different connectors. You need the right tip for your laptop. This is very simply to find. Basically, AC adapters comprise of 2 ends. One end is male power outlet. You use this end to plug into wall power outlet. The other end is called “”TIP”” which you will plug this tip into the “”DC IN”” in your laptop.
Your laptop won’t work on the wrong tip. You can only use the “” matching Tips””
Warning : DO NOT try to force it in.


2. Finding the right “”output voltage”” – Different laptops were designed to consume power varied by equipments such as CD-Rom, LCD size, CPU maker and CPU speed. You require to use the “”matching voltage”” . Only use the AC adapters output the matching voltage of your laptops. You can easily locate your laptop voltage. Mostly, voltage is printed on your laptops. You also can check your laptop manual.
3. Find the right “”input voltage”” – for tdose users who will travel abroad especially to Europe and Asia. You would need laptop adapters that compatible with 220-240 voltage also. So it would be wise…and yes…you are!!…. Always look for AC adapters accept 100~240 voltages. 100~240 voltages laptop adapters will go with you worldwide. You do not need to carry 2 adapters anymore!!!.
that’s easy!!! You now know the basic knowledge to find your laptop  adapters.
Better yet!!! laptop adapter manufacturers are now promoting “”universal laptop adapters”” .
this emerging adapters can be used with multiple devices. They can accept 100~240 input voltages and also adjust the output voltage to match device automatically.

laptop keyboard

How to Replace a HP COMPAQ Laptop Keyboard

Leave a comment

Laptop computers are designed to be more convenient to transport and use than desktop computers. Unfortunately, their compact all-in-one design can make them significantly more difficult to work on when you have to attempt to upgrade or repair them. When attempting to replace a keyboard on a HP COMPAQ laptop, you might discover the frustration of having to repair a laptop firsthand; fortunately, these repairs are generally much easier to actually perform than they may seem at first. Replacing a HP COMPAQ laptop keyboard should only take a few minutes, meaning that your laptop can be fully functional again in no time flat.

Step 1 Visit the HP COMPAQ support document website and locate the “”User’s Guide”” section of the listings for your laptop model. You should be able to locate either a “”component replacement manual,”” or a document focusing specifically on replacement of the keyboard for that model (as different models of keyboards have slightly different methods of removing the keyboard.) You may also wish to check the FAQ’s in the support documents of your model, as they may also contain information on replacing the keyboard.

Step 2 Power down your HP COMPAQ laptop and remove the battery. This will not only ensure that you don’t accidentally damage your laptop by powering it up while working on its components, but may also be necessary to reach the mounting screws for your laptop’s keyboard. Press the power button once after the battery has been removed to discharge any remaining electricity that the laptop may have stored.

Step 3 Consult the support documents for your HP COMPAQ laptop model and find out where the keyboard mounting screws are located. There will most likely be between two and five screws, depending on the specific model of laptop that you own. You may be required to remove the keyboard bezel (the strip of plastic that runs along the top of the keyboard) in order to reach some or all of the screws; this can be done either by sliding the bezel off to the right of the laptop or by simply lifting it off once loosened (though you may need to use a coin or flat-head screwdriver to detach clips or pry the bezel out of its resting location.)

Step 4 Remove the screws holding the keyboard in place. The screws will either be located on the bottom of the laptop (under the space that the battery occupies) or beneath the keyboard bezel. Put the screws in a safe place where they will not be lost, since you will need to use them to secure the new keyboard.

Step 5 Lift the keyboard up from the bottom, detaching the keyboard connector and pulling the keyboard itself free from the HP COMPAQ laptop, then setting it aside. You may need to once again use a coin or flat-head screwdriver in order to depress clips which might be holding the keyboard in place.)

Step 6 Plug your new keyboard into the keyboard connector, then carefully place it back into the space previously occupied by your old keyboard. If the keyboard is designed to be held in place by clips, press down with sufficient pressure to clip the keyboard into place.

Step 7 Replace the screws that you had previously removed from the HP COMPAQ laptop. Make sure that the screws are firmly in place both to ensure that the keyboard is secure and also to eliminate any potential problems with replacing the bezel or battery.

Step 8 Reattach the bezel (if you removed it) and the laptop battery, making sure that all components have been reattached and are firmly secured. Once the battery is back in place, press the power button to power up the HP COMPAQ laptop and give your operating system a chance to recognize the newly-installed keyboard.

Tips & Warnings
Because of different style considerations, some HP COMPAQ laptops may require additional components such as the monitor to be removed in order to remove the bevel or replace the HP COMPAQ keyboard. Make sure that you read the appropriate support document in order to know exactly what your laptop will need before you start. When ordering or buying a new keyboard for a HP COMPAQ laptop, make sure that the keyboard that you purchase is designed for your specific model of laptop before you buy.Make sure that you stay in contact with a grounded metal object, or otherwise discharge static electricity when working on your laptop to prevent the damage that static buildup can cause to computer components.

laptop battery

How long of laptop battery runtime

Leave a comment

The laptop battery runtime is governed by other attributes than the specified capacity alone.

This paper examines the cause of unexpected downtime and short laptop battery service life. We look at four renegades – declining capacity, increasing internal resistance, elevated self-discharge and premature voltage cut-off on discharge. We evaluate how these regenerative deficiencies affect nickel, lead and lithium-based batteries.

Declining capacity
The amount of charge a battery can hold gradually decreases due to usage and aging. Specified to deliver 100% capacity when new, the laptop battery should be replaced when the capacity drops to below 80% of the nominal rating. Some organizations may use different end-capacities as a minimal acceptable performance threshold.

The energy storage of a battery can be divided into three imaginary sections consisting of: available energy, the empty zone that can be refilled, and the unusable part (rock content) that increases with aging.

In nickel-based batteries, the so-called rock content is present in form of crystalline formation, also known as memory. Restoration is possible with a full discharge to one volt per cell. However, if no service is done for four months and longer, a full repair becomes increasingly more difficult the longer service is withheld. To prevent memory, nickel-based batteries should be deep-cycled once every one or two months. Nickel-cadmium and nickel-metal-hydride batteries are used for two-way radios, medical instruments and power tools.

Performance degradation of the lead-acid battery is caused by sulfation and grid corrosion. Sulfation is a thin layer that forms on the negative cell plate if the laptop battery is being denied a fully saturated charge. Sulfation can, in part, be corrected with cycling and/or topping charge. The grid corrosion, which occurs on the positive plate, is caused by over-charge. Lead-acid batteries are used for larger portable devices and wheeled applications.

Lithium-ion batteries lose capacity through cell oxidation, a process that occurs naturally during use and aging. The typical life span of lithium-ion is 2-3 years under normal use. Cool storage a 40% charge minimizes aging. An aged lithium-ion cannot be restored with cycling. Lithium-ion is found in cell phones and mobile computing.

Increasing internal Resistance
The capacity of a laptop battery defines the stored energy – the internal resistance governs how much energy can be delivered at any given time. While a good laptop battery is able to provide high current on demand, the voltage of a laptop battery with elevated resistance collapses under a heavy load. Although the laptop battery may hold sufficient capacity, the resulting voltage drop triggers the ‘low battery’ indicator and the equipment stops functioning. Heating the laptop battery will momentarily increase the output by lowering the resistance.

A laptop battery with high internal resistance may still perform adequately on a low current appliance such as a flashlight, portable CD player or wall clock. Digital equipment, on the other hand, draw heavy current bursts.

Nickel-cadmium offers very low internal resistance and delivers high current on demand. In comparison, nickel-metal-hydride starts with a slightly higher resistance and the readings increase rapidly after 300 to 400 cycles.

Lithium-ion has a slightly higher internal resistance than nickel-based batteries. The cobalt system tends to increase the internal resistance as part of aging whereas the manganese (spinel) maintains the resistance throughout its life but loses capacity through chemical reaction. Cobalt and manganese are used for the positive electrodes.

High internal resistance will eventually render the laptop battery useless. The energy may still be present but can no longer be delivered. This condition is permanent and cannot be reversed with cycling. Cool storage at a partial state-of-charged (40%) retards the aging process.

The internal resistance of Lead-acid batteries is very low. The battery responds well to short current bursts but has difficulty providing a high, sustained load. Over time, the internal resistance increases through sulfation and grid corrosion.

Elevated self-discharge

All batteries suffer from self-discharge, of which nickel-based batteries are among the highest. The loss is asymptotical, meaning that the self-discharge is highest right after charge and then levels off. nickel-based batteries lose 10% to 15% of their capacity in the first 24 hours after charge, then 10% to 15% per month afterwards. One of the best batteries in terms of self-discharge is Lead-acid; it only self-discharges 5% per month. Unfortunately, this chemistry has the lowest energy density and is ill suited for portable applications.
lithium-ion self-discharges about 5% in the first 24 hours and 1-2% afterwards. Adding the protection circuit increases the discharge by another 3% per month. The protection circuit assures that the voltage and current on each cell does not exceed a safe limit.

The self-discharge on all battery chemistries increase at higher temperatures. Typically, the rate doubles with every 10°C (18°F). A noticeable energy loss occurs if a battery is left in a hot vehicle.

Aging and usage also affect self-discharge. nickel-metal-hydride is good for 300-400 cycles, whereas nickel-cadmium may last over 1000 cycles before high self-discharge affects the performance. An older nickel-based battery may lose its energy during the day through self-discharge rather than actual use. Discard a battery if the self-discharge reaches 30% in 24 hours.

Nothing can be done to reverse this deficiency. Factors that accelerate self-discharge are damaged separators induced by crystalline formation, allowing the packs to cook while charging, and high cycle count, which promotes swelling in the cell. Lead and lithium-based batteries do not increase the self-discharge with use in the same manner as their nickel-based cousins do.

Premature voltage cut-off
Not all stored laptop battery power can be fully utilized. Some equipment cuts off before the designated end-of-discharge voltage is reached and precious battery energy remains unused. Applications demanding high current bursts push the battery voltage to an early cut-off. This is especially visible on laptop batteries with elevated internal resistance. The voltage recovers when the load is removed and the battery appears normal. Discharging such a battery on a moderate load with a battery analyzer to the respective end-of-discharge threshold will sometimes produce residual capacity readings of 30% and higher, jet the battery is inoperable in the equipment. Figure 4 illustrates high cut-off voltage.

High internal  laptop battery resistance and the equipment itself are not the only cause of premature voltage cut-off – warm temperature also plays a role by lowering the laptop battery voltage. Other reasons are shorted cells in a multi-cell battery pack and memory on nickel-based batteries.

power adapter

How to Replace an AC Adapter on an HP Compaq?

Leave a comment

The HP Comapq is a good laptop for the most part, but its weakest component is the place where the HP Compaq AC Adapter plugs into the back of the unit. The connection often comes loose and at times can melt the power cord. Before repairing the unit, it is a good idea to make sure the power cord you have for the unit is a 90-watt adapter, because the problems will continue if a lower wattage HP Compaq AC Adapter is used.
Here are some steps for how to deal with this problem
Remove the case from the laptop. There are a number of small screws that must be removed before the case can be opened. Clear enough space around the Replace a HP Compaq AC Adapter area to give yourself room to work. Run a voltmeter over the wires of the circuit board near the connector to determine if there is an electrical short.
Use the soldering wire to repair any electrical shorts. Usually, it is a connection to the HP Compaq AC Adapter connector that is damaged on the HP Compaq motherboards, not the connector itself.
Use the needle-nose pliers to ply the connector off the motherboard carefully. Do this step only if the power connector itself needs to be replaced. Gently place the new connector back onto the slot where the old one stood, and use the soldering iron to complete the electrical connections. Solder the new HP Compaq AC Adapter power connector onto the motherboard.
If everything is working, place the laptop casing back on and computer away. If the unit still does not come on, take the case back off and use the voltmeter to test for loose connections.
Notice: HP Compaq laptops use 90 W power cords. Make sure the power cord you are using is the right wattage, if you do not have the original HP Compaq AC Adapter provided by HP. If you want to buy other laptop accessories, laptop ac adapter, you can visit http://www.socanpower.ca  .

laptop battery

Dell Latitude D620 Laptop Battery Review

Leave a comment

The Latitude D620 is equipped with the latest Intel®  Centrino®  Duo Mobile Technology: an available dual-core Intel®  Core™2 Duo processor, choice of Intel 945 GM or 945 PM chipset and Intel PRO/Wireless 3945 Wi-Fi®  mini-card. These components ensure to get the best possible mobile performance while using less battery power than previous-generation technologies. Choose a 6- or 9-cell battery and take advantage of the power savings features of Centrino®  Mobile Technology to stay productive longer. Plus, you can quickly and easily customize your power settings with Dell QuicksetTM  software.

Sunvalleyus Dell Latitude D620 batteries and chargers come with 6 months warranty and 100% compatibility guarantee. Physically, this item is nearly identical to the Dell branded battery. There are no quality issues at all. It does have the battery meter on the bottom, just like the original one. This high capacity rechargeable battery definitely disposes of more power than the original rechargeable battery included in delivery of the unit. This rechargeable battery can be used instead of the original rechargeable battery without any problems and can be recharged with the available standard power supply. The rechargeable battery is protected and secured against overcharge and short-circuits.

Features of   Dell Latitude D620 battery :


Voltage: 11.1V
Capacity: 4400mAh
Type: Li-ion
Number of cells: 6
UL certificated cells inside!
100% OEM compatible, guaranteed to meet or exceed OEM specifications!

Does your Dell Latitude D620 battery seem to only last an hour when you use it? Promises of 6-8 hour battery life spans were calculated under ideal circumstances. However, the average user is much more demanding on their laptop. So how to increase and extend your laptop battery life?
There is always a guide for the step ahead:

Step 1 Eliminate any extra programs running in the background. Although these applications can’t be seen, they are still using energy to run.

Step 2 Dim your screen to the lowest level tolerable. A bright screen uses a significant amount of power.

Step 3 Avoid leaving CD’s or DVD’s in your drives. When you start your computer up these disks take up valuable power being read and loaded. Every tiny bit of power counts.

Step 4 Keep your Dell Latitude D620 battery connections clean. Dirty or corroded contacts can drain power even when your laptop isn’t currently on.

Step 5 Add more RAM to your laptop. This will help you use “”real memory”” instead or virtual memory. Virtual memory uses more hard drive and energy space. Adding additional RAM can be expensive, but is a great way to extend the battery life of your laptop.

Sunvalleyus strives to make your computer battery purchase easy. Since finding the right batteries for your needs can be overwhelming and confusing at times, it has developed a laptop battery search tool to help find the right size for the make and model of your equipment. It also offers educational articles and tips to help you conserve your laptop batteries and fix common problems. All in all, buying a cheap replacement like this is worth saving money on dell’s prices.