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  Dell MR90Y laptop battery

Dell Latitude MR90Y laptop battery

List Price: $129.99
Our Price: $99.90
Off List Price$30.09!

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Dell MR90Y 65 Whr Battery

This is a brand new Dell MR90Y replacement battery. This is the 65 Whr battery which is an improvement over the 40 Whr battery that was included with many Dell laptops. The 65 Whr battery has more than 60% more run time capacity than the original 40 Whr battery. Depending on the size of your laptop screen and the power consumption settings of your laptop, you will get 4- 6 hours of run time with this battery.

There are two key components inside your battery pack to look for when buying a new computer battery. The quality of the battery’s lithium-ion cells and the quality of the computer chip set in the battery pack. This battery is built with the best components, not the cheapest.
This battery contains the very best Li-ion cells on the market from Samsung. An important specification to look for with rechargeable batteries is the mAh (mili amp hour) rating or Whr (Watt Hour). This battery is rated at 65 Whr. This is the highest rating available for a 6 cell battery pack. The higher the mAh rating, the longer your battery will run before it needs to be recharged again. There are no compatibility issues if your existing battery is rated at 40 Whr or a lower Whr. Simply put, more is better.
The other key component inside the battery pack is the computer chip set that contains the program interface with your laptop’s battery meter software and important safety features that monitors when to charge and stop charging your battery. We use Texas Instruments top notch components for this.
When choosing a laptop battery, cheaper is not better. Cheaper batteries use inferior Chinese cells that typically wear out in just 3 to 6 months. The main indicators of inferior Chinese cells are the low price of the battery and a lower mAh rating. Inferior batteries also use inferior computer chip sets inside that can lead to compatibility issues with your laptop. Although every brand of laptop battery is hand assembled in China, the key to getting a great battery is knowing what components are inside.
Laptop Battery Express is a US based business with knowledgeable support staff to assist you before and after the sale. Yes, we have a phone number and real people answer your call! Free technical support is available if you need additional help in diagnosing power problems with your battery, ac power adapter or battery meter software.
All our products carry a full 2 Year warranty and every battery is charged and tested before it ships.
We provide a 30 day money back guarantee if you are not completely satisfied. We are so confident in the quality of our batteries, we will pay for any and all shipping expenses if our product fails to perform in the first 30 days you have our battery, even if it is not our fault. (PS- if your laptop will not turn on at all when plugged –in, you need a new ac power adapter found at the bottom of this page) Feel free to call for tech support.

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  • xTend computer battery
  • 11.1 Volts
  • 65 Whr
  • 6 Cell Li-ion
  • Samsung (South Korea)
  • Black
  • 2 Year Warranty
  • 30 day full satisfaction guarantee
  • 300-500 recharge cycles

You can expect up to 4 - 6 hours of run time with this computer battery when new, depending on your energy use.

This battery replaces the Dell MR90Y Series batteries.

Replaces these many Dell laptop battery part numbers:



Laptop Battery Express only deals with brand new premium computer batteries. We never carry recycled or used batteries. We only use the highest quality cells inside the battery pack so you will have a long service life (300-500 recharge cycles). We do not use cheaper battery cells which can wear out in a little as 3 to 6 months. Our inventory turns rapidly and you will always receive a freshly manufactured battery.

How to care for your Dell MR90Y battery.

You can extend the life of your laptop battery significantly through the proper care and handling of your battery.

  • Any new laptop battery should first be fully charged by leaving it plugged in overnight. Once a computer battery is fully charged it will no longer accept any more power. It is a common practice to leave laptops plugged in after they have been turned off so that the battery has a full charge the next time you use your laptop. It is probably fully charged within 5 hours.
  • A brand new notebook battery is in a weakened condition since it has not been conditioned yet. Condition and break in your new battery by performing 5 partial discharge and recharge cycles the first week you receive your new battery.
  • Run on battery power without the AC adapter cord at least once a week to keep the battery cells active and at their peak potential. When your laptop is plugged into the power adapter the battery goes to "standby mode" while your laptop runs directly on electricity from the wall outlet.
  • Even though your battery indicates it is fully charged, your battery will return to a weakened state again in a few months if it does not get some exercise through partial discharge and recharge cycles while running on battery power alone.
  • If your battery has not been actively used 2 months or more, condition your battery again with 5 partial discharge & recharge cycles to increase the batteries capacity and run time.
  • Don't run your battery all the way to empty. Your battery will have a longer service life if it receives shallow discharge and recharge cycles. Research has shown that the useful life of the battery will be much longer if you begin to recharge the battery any time before reaching 20% of the remaining power capacity. Recharging the battery even after 10 minutes will not reduce the battery's life span as lithium batteries do not have the memory effect which was found in older NiCad battery technology. NiCad batteries have never been used in laptops, even the earliest models.
  • Never run your battery below the 3% critically low warning point. If your battery is run below this point it may not have enough energy to recharge. This may effectively "kill" your battery.

How can I extend my Dell MR90Y battery run time?

You can extend your battery run time by minimizing the power drain on your battery. A 6 cell battery will run approximately 4 to 6 hours when the battery is new. Even longer times can be achieved by minimizing the power consumption of your laptop. Here are the top ways to reduce your power consumption.

  • Reduce the brightness of your laptop screen. This is the main drain on your Dell MR90Y battery by far.
  • Avoid using the CD or DVD drive as the motor consumes a fair amount of power.
  • Turn off your wireless finder if you are not using the internet.
  • Remove any devices plugged into your USB ports or other ports.
  • Close out programs you are not using. By minimizing the load on your CPU, sometimes you can avoid having the cooling fan turn to its high speed mode.
  • Increase your memory to at least 4 Gigabytes. This creates less work for your hard drive. Data is temporarily written to your hard drive when your memory is not sufficient to hold all the data on the many pages you may be accessing.

Compatible AC Power Adapters designed for this product
ac adapter for Dell PA10
Our Price: $59.00

PA10 dell ac adapter 310-2862 310-3399 310-4002 310-7698 310-7699 FF313

This battery & adapter are compatible with the following laptop models. In addition, if your battery or adapter part number matches the list above, this battery will be comapitble even if your specific computer is not listed.

Dell Laptop Batteries > Inspiron 14R (5437)
Dell Laptop Batteries > Inspiron 15R (5537)
Dell Laptop Batteries > Inspiron 17 (3737)
Dell Laptop Batteries > Inspiron 17R (5737)
Dell Laptop Batteries > Latitude 3440
Dell Laptop Batteries > Latitude 3204
Dell Laptop Batteries > Inspiron 14R
Dell Laptop Batteries > Inspiron 3421
Dell Laptop Batteries > Inspiron 5421
Dell Laptop Batteries > Inspiron N3421
Dell Laptop Batteries > Inspiron N5421
Dell Laptop Batteries > Inspiron 15R
Dell Laptop Batteries > Inspiron 15-3521
Dell Laptop Batteries > Inspiron 15-5521
Dell Laptop Batteries > Inspiron 15-N3521
Dell Laptop Batteries > Inspiron 15-N5521
Dell Laptop Batteries > Inspiron 15R-3521
Dell Laptop Batteries > Inspiron 15R-5521
Dell Laptop Batteries > Inspiron 15R-N3521
Dell Laptop Batteries > Inspiron 15R-N5521
Dell Laptop Batteries > Inspiron 3521
Dell Laptop Batteries > Inspiron 5521
Dell Laptop Batteries > Inspiron N3521
Dell Laptop Batteries > Inspiron N5521
Dell Laptop Batteries > Inspiron 17R
Dell Laptop Batteries > Inspiron 17-3721
Dell Laptop Batteries > Inspiron 17-5721
Dell Laptop Batteries > Inspiron 17-N3721
Dell Laptop Batteries > Inspiron 17-N5721
Dell Laptop Batteries > Inspiron 17R-3721
Dell Laptop Batteries > Inspiron 17R-5721
Dell Laptop Batteries > Inspiron 17R-N3721
Dell Laptop Batteries > Inspiron 17R-N5721
Dell Laptop Batteries > Inspiron 3721
Dell Laptop Batteries > Inspiron 5721
Dell Laptop Batteries > Inspiron N3721
Dell Laptop Batteries > Inspiron N5721
Dell Laptop Batteries > Vostro 2421
Dell Laptop Batteries > Vostro 2521