Laptops For Less Blog

Rechargeable Batteries: Q&A [Part II]

Welcome to part II of “Rechargeable Batteries: Q&A”. In this section of the article we’re going to look at some important questions [and of course answers] on rechargeable batteries! Read on…

Have you ever wondered how many charges your NiMH rechargeable batteries get?

If a rechargeable battery is under constant use it’s going to eventually die. Batteries don’t last forever. They lose some of their capacity with every charge. Most manufacturers and customers claim that batteries recharge between 150 and 500 times. Some manufacturers suggest their product last up to 1,000 charges. However, a poorly maintained battery may only last about 100 hours. The following factors also affect the life of your rechargeable battery:

1. Power drain. How much power is your device using at one time? If it’s slow and steady, you may get longer runtime than a device that powers in short bursts. For example, a strobe-flashing camera.
2. Discharge frequency. How many times are you discharging your battery? Read your manual for suggestions.
3. Temperature. Keep operation temperature in mind. You’ll want to keep your battery at a temperature between of 60-70 degrees Fahrenheit.
4. Recharging patterns. Recharge NiMH batteries often. You’ll also want to recharge batteries that sit around for long periods of time.

How long can be batteries be left in a charger?

Most battery experts are against leaving batteries in a charger for a long stretch of time. Always check the instructions that came with your charger for details. They typically include the suggested battery re-charge times. Most chargers have an indicator that tells you when the battery is fully charged. Most new chargers have automatic shutoff features. If so, you can leave the battery on the charger indefinitely.

Why is my battery warm during recharging?

NiMH and NiCd batteries get warm during the recharge process. Lithium-ion batteries do not. If you’re using a rapid charger the batteries will feel very warm during its 15 minute recharge. If you have a slow charger and you notice
excessive heat this could mean problems for your battery and charger. Caution: If you determine any battery leakage stop the charging process immediately.

Is there such a thing as “ideal” battery charging conditions?

Many experts suggest 68 degrees Fahrenheit. This is standard room temperature. Avoid temperature extremes. Operating a device with a rechargeable battery in very warm conditions reduces the overall performance of the battery. Using a
device in cold conditions makes the electrolyte in the battery “sludgy”.

Is one kind of charger better than another kind of charger?

Not really. They all tend to have advantages and disadvantages. Review the following items to get a good idea about battery chargers in general:

• Never attempt to recharge a NiMH battery in the older timer-based NiCd chargers. This could cause an overcharge. Don’t recharge an older NiCd battery in a NiMH battery designed charger. FYI: Did you know one type of NiMH battery
recharges using a computer USB slot!

• The “smart” charger. Smart chargers come loaded with microprocessors that automatically shut off energy flow when the battery is fully charged. Some smart chargers “trickle charge” also. This type of charger tops off energy levels until the battery’s next use.

• Most chargers are “dumb” chargers. These are basic chargers that do not have an auto shutoff, or any other features. The user must keep a watchful eye on these chargers to make sure that their batteries don’t overheat.

• Use “quick” chargers versus slow “overnight” chargers when it comes to NiMH batteries. Quick chargers usually charge between 3 and 6 hours. This is quick because a higher current is used. Most experts believe rechargeable batteries
last longer when charged at higher currents. Overnight chargers take up to 12 hours or more to charge a battery and don’t automatically shut off. This puts the battery at risk of overcharging or other types of damage. Sure signs of overcharging include excessive heat and leakage. Be on the lookout.

• “Rapid chargers” are one of the newest types of chargers. These chargers use I-C3 or In-Cell Charge Control technology. Rapid chargers can refuel a NiMH battery in as little as 15 minutes.

• Top off batteries not used for a few days or weeks before using them. If the battery is a NiMh and not used in years it may require 2-3 recharge-discharge cycles to activate the electrolyte again. If you find yourself in this situation use a quick charger instead of a rapid charger. Remember: most smart chargers offer a conditioning cycle.

• Never recharge a single-use battery. Single-use batteries are alkaline, lithium, and heavy duty varieties. Note: some alkaline batteries are rechargeable. However, these batteries are limited to a number of recharges and not recommended.

• Conditioning may be necessary. Conditioning helps revive a rechargeable battery exhibiting poor performance or short charges. Visit an electronics shop or go online to find a compatible charger with a conditioning cycle if necessary.

• Look at your manufacturer manual and product descriptions for charging cycles times to determine a charger’s capabilities. The terms used in this list: slow or overnight [12+ hours], quick [3 to 6 hours], rapid [15 minutes], and smart
[microprocessor equipped] are not standard.

LaptopsForLess.com has a huge selection of batteries in stock, at very reasonable prices [often a fraction of the cost of manufacturers’ own brand replacements]. We stock; Laptop Batteries, Power Tool Batteries, PDA Batteries, Camera/Camcorder Batteries, Cell Phone Batteries and much more. If an electronic device contains a battery, we’ll stock that battery!