When you have finally decided to purchase s new replacement battery for your laptop you should ensure that the manufacturer has a reliable reputation. If the battery is manufactured by the maker of the laptop then you can rest assured that the battery will be reliable. However, it might come as a surprise to you that most manufacturers of laptops, even the most reputed ones do not manufacture batteries but have an ancillary unit doing so in their name. For instance, if you were to open a genuine Sony battery (not recommended) you will find that he cells inside are manufactured by Toshiba, Exide or some other battery manufacturer. So in the final analysis you are, in fact, buying third party batteries for your laptop. The third party manufacturers of laptops are also buying their cells from the same manufacturers that are supplying the so called OEMs and so is a good bet to buy your replacement battery from. Besides the lower price you will get additional benefits such as an extended warranty and replacement offers. A one year replacement warranty is a must for your replacement battery, so never settle for less.
The other thing to look for when buying a replacement battery is the type of battery. Manufacturers will use many different technologies however, for laptops there are four technologies used. These are Ni-Cad, Ni-MH, Li-Ion, and Li-Poly out of these Ni-Cad or nickel cadmium batteries are a very rare commodity and are being phased out gradually. Don’t go in for a Ni-MH battery if you have a choice between this and a Li-Ion or Li-Poly battery because the Ni-MH battery weighs much more than the rest and have a lower power to weight ratio, meaning it delivers less power than its lighter weight counterparts. Li-Ion and Ni-Poly batteries are the most advanced and last longer. So try for one of these two technologies. Some laptops are designed to use the kind of battery it originally came fitted with, this means if it came with a Ni-Cad battery it must be replaced with a Ni-Cad battery. This is because the internal circuit of the battery must match the laptop hardware for optimum charging and discharging. However, this is not always the case so check with your manufacturer of the laptop if the battery can be interchangeable. Lifepo4 Battery Manufacturers
Finally you must study the power ratings of the battery you are buying. Batteries are growing smaller and the power capacity is increasing. Batteries have two ratings marked on them. One will be the voltage and the other Amperes. When buying your replacement battery buy one with the same voltage rating as the old one but try to get a battery with a higher ampere rating. This battery will have longer charge cycles.
Many batteries are rated in watt-hours. This is perhaps the simplest way to rate a battery. The wattage of a battery is calculated by multiplying the voltage by the amperage so a battery with a 14.4 volt rating and an ampere rating of 3600mAh (3.6 Amps) will have a watt rating of 51.84 watts (14.4X3.6 = 51.84).
If the power rating on the battery reads 51.84 watt-hours it means that the battery can supply 1 watt of power continuously for 51.84 hours or 51.84 watts of power for one hour or any combination of the two. No suppose your laptop runs on 17.28 watts (which is pretty unlikely) a 51.84 watt battery will power it for 3 hours. SO divide the power ratings in watts of the battery by the watts of your laptop to see how long the battery will run your laptop.