Rechargeable Battery Technology-Important Answers to Great Battery Questions!

How long will my battery last?

Thank you for the question. There are two factors that govern how long a battery will last: runtime and charge-discharge cycles.

Runtime is a measure of how much time can elapse before a fully charged battery reaches a charge of 0%. Technically a battery never reaches a 0% charge but a low charge does not permit enough power to be transmitted to the device.

Runtime is controlled by capacity and usage. Capacity is measured in Amp hours or milliamp hours. Battery capacity quantifies the total amount of energy stored within a battery. More capacity equals longer runtime between battery charges. Hence if you want a battery to last the longest possible be sure to buy a battery with the highest possible capacity. For example a battery it a capacity of 2000 mAh will last longer in between charges than a battery with 1500 mAh capacity.

Runtime is also increased or decreased by usage.

All batteries slowly drain regardless if you are using it in your device or not! Once charged an electron flow occurs in a battery and once begun the electron flow will continue until the chemical is exhausted.

Chemical depletion occurs with every charge-discharge cycle. What is actually occurring during this charge-discharge cycle is replenishing spent electrons (i.e. creating current – an electrical flow)). In batteries electricity is created by charging two chemicals in a solution. This is done by applying an electrical flow (i.e. from a wall or car charger or solar charger) to the battery’s lithium.

Charging lithium can be thought of as the introduction of ions or movement of chemistry. To move the lithium chemistry (lithium-ion, lithium polymer, lithium iron phosphate, etc) you have to have a minimum voltage applied to the lithium. Most battery cells are charged to 4.2 volts with relative safe workings at about 3.8 volts. Anything less than 3.3 volts will not be enough to charge or move the chemistry. One thing to note here is that volts are an algorithmic measurement of current. So in a sense to create current through your battery you have to introduce current into your battery’s lithium .

Introducing current into your lithium is called intercalation. Intercalation is the joining of a molecule (or molecule group) between two other molecules (or groups). When it comes to charging your battery you are in effect pushing ions in and out of solid lithium compounds. These compounds have minuscule spaces between the crystallized planes for small ions, such as lithium, to insert themselves from a force of current. In effect ionizing the lithium loads the crystal planes to the point where they are forced into a current flow. The current flow is then channeled back and forth from anode to cathode and thereby creating an electrical flow to power on your device. Again this can done 300-500 times before all the ions are pushed out of the lithium and you will no longer be able to charge your device.

The number of charge-discharge cycles that can be done to a battery ranges between 300 and 1000 times depending on the chemical of the battery. In addition after each charge-discharge cycle the runtime (time between charges) is reduced by intercalation as discussed above. For example you may notice in the first 3-4 months you are getting between 3-5 hours of runtime on your battery. Then in months 5-12 (after your purchase) you notice that you are slowly getting less and less runtime in between charges until you might be getting less than 5 minutes of runtime. This is the normal use of the chemistry inside your battery and DOES NOT mean that the battery is bad, but simply the chemical has been spent.

Should I charge my battery before I use it, each time I use it, and/or during storage?

Initial Charging: When you first get your battery you should charge it until your charger or device indicates that it is fully charged. If your device/charger does not indicate whether or not it is fully charged, then check your device/charger manual for charging times. It can take 1-12 hours to fully charge depending on the chemistry of your battery and the type of device and charger. After that it is good to charge it as needed while making sure you do not leave it at a low charge level for long periods. Also, please keep in mind that it can take 2-4 initial full charges/discharges before a new battery begins to provide maximum performance/runtime.

Recharging: Your battery was designed to be charged regularly and should NOT be left at a low charge level for long periods. You should charge it as often as needed to prevent the charge level from getting much below 15% of full.

Charging During Storage: During storage your rechargeable battery will trickle discharge naturally (or slowly lose its current charge). Long storage periods can permanently diminish the overall life of the battery especially when the battery is left at a low charge level for too long. If you will be storing your battery for a long period of time, be sure NOT to store it at a low charge level. Bring the charge level up to full before storage and then top off the charge level as needed during storage (to prevent it from sitting too long at low charge). It is highly recommended, even during storage, that you charge the battery regularly to prevent the possibility of the battery sitting at low charge for too long (sitting at low charge for too long will cause deep discharge which can permanently damage the cells and render the battery useless). Damage from deep discharge is NOT a defect and therefore it is not covered by warranty. For rechargeable lithium batteries in storage (including lithium ion and lithium polymer), a full recharge might be needed every 3-6 months. For rechargeable nickel batteries in storage (NICD and NIMH), a full recharge might be needed every 1-2 months. Nickel batteries trickle discharge in storage faster than lithium batteries.

What will cause my battery to lose power?

A battery over time degrades and eventually stops working. In fact the battery from its very first charge begins a very slow process that causes the battery to cease from functioning. Collectively the process is called battery degradation and power loss and it includes the following: declining capacity, increasing internal resistance, elevated self-discharge, and premature voltage cut-off on discharge.

Declining capacity is when the amount of charge a battery can hold gradually decreases due to usage, aging, and with some chemistry, lack of maintenance.

The loss of charge acceptance of the Li ion/polymer batteries is due to cell oxidation. Cell oxidation is when the cells of the battery lose their electrons. This is a normal process of the battery charge creation process. The capacity loss is permanent because the metals used in the cells run for a specific time only and are being consumed during their service life.

Internal resistance, known as impedance, determines the performance and runtime of a battery. It is a measure of opposition to a sinusoidal electric current. A high internal resistance curtails the flow of energy from the battery to a device. The aging of the battery cells contributes, primarily, to the increase in resistance as does cell oxidation. Interestingly energy may still be present in the battery, but it can no longer be delivered due to poor conductivity.

Elevated Self-discharge: All batteries have an inherent self-discharge. The self-discharge on nickel-based batteries is 10 to 15 percent of its capacity in the first 24 hours after charge, followed by 10 to 15 percent every month thereafter. Li-ion batteries self-discharge about five percent in the first 24 hours and one to two percent thereafter in the following months of use. At higher temperatures, the self-discharge on all battery chemistries increases. The self-discharge of a battery increases with age and usage. Once a battery exhibits high self-discharge, little can be done to reverse the effect. Be sure never to leave a rechargeable battery at low charge for long periods, even during storage. 

Premature Voltage Cut-Off: Some devices do not fully utilize the low-end voltage spectrum of a battery. A device may cut itself off before the designated end-of-discharge voltage is reached leaving battery power in the battery unused. For example, a pda that is powered with a single-cell Li ion battery and is designed to cut-off at 3.7V may actually cut-off at 3.3V. Obviously the full potential of the battery and the device is lost (not utilized). Why? It could be something with elevated internal resistance and or operations at warm ambient temperatures. Devices that load the battery with current bursts are more receptive to premature voltage cut-off than analog equipment. High cut-off voltage is mostly equipment related, not battery.

Does the battery come with installation instructions?

We offer a instructions for a wide variety of batteries that require more complex installs then snap or slide-on batteries. To see if installation instructions are necessary and are provided then please check with a top-battery representative.

Does the battery come with a tool kit?

If a tool kit is provided you will see that listed in the description of the battery. And the best thing to do is to look for the image of a tool kit. If you see one on the page then a tool kit will be provided.

Does my battery self discharge when not in use? What is the rate of Self-Discharge of the battery?

All batteries will self discharge over a period of time naturally whether the battery is used or not. This means that the battery capacity will go from 100% down to 0% over a time period regardless if the battery is being used or not. Recharging the battery corrects this naturally occurring reality.

Battery self discharge rate varies based on the chemistry type used and the temperature the battery is at: higher temperatures increase the self-discharge rate. This explains why batteries left inside cars on hot days must be recharged more frequently!

Battery self-discharge is a phenomenon in batteries in which internal chemical reactions reduce the stored charge of the battery. Battery self-discharge does decrease the overall shelf-life of batteries and causes them to initially have less than a full charge when actually put to use.

Here are average self discharge rates for the following chemistries:

	NiCd	NiMH	Lead Acid	Li-ion	Li-ion polymer	Reusable Alkaline
Self-discharge / Month (room temperature)	20%	30%	5%	1-5%	~10%	0.3%

To reduce the rate of battery self discharge during storage, store the battery at lower temperatures (not necessarily in a refrigerator or freezer, 50-72F is sufficient). This also preserves the initial energy stored in the battery.

Be sure never to leave a rechargeable battery at low charge for long periods, even during storage. 

My new battery isn’t working or charging. Is it defective?

New batteries come in a partially discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge the new battery two to four times to allow it to reach its maximum rated capacity.

Also it is normal for a battery to become warm to the touch during charging and discharging. When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is normal with rechargeable batteries. New batteries are harder for the device to charge; they have never been fully charged and so they are not “broken in.” If this happens, let the battery and device cool and then discharge the battery by using the device until it shows low charge again and then recharge to full.

Be sure never to leave a rechargeable battery at low charge for long periods, even during storage. 

Will my device’s performance differ if I use your aftermarket battery?

Replacement batteries or “aftermarket” batteries will often last longer and provide more runtime than the original equipment manufacturer (OEM) batteries that came with your device. We design the compatible battery replacement so that it provides the necessary voltage as required by your particular device/model. In most cases our factories manufacture the batteries to meet or exceeed the OEMs specifications so that you will see the same or better performance as the OEM battery. In some cases, it is not possible or practical to make a replacement battery’s capacity/runtime better than the original. In rare cases, our factories may find it impractical to make the replacement battery’s capacity/runtime even as high as the original.

Will your battery fit my device?

Yes. We conform our battery designs to meet the specifications of your device. The physical footprint of the battery was tested and made to fit your device.

I do not see my model listed in your Compatible Model List? Will your battery fit?

We do our best to list as many models that our batteries fit with, but inevitably we sometimes miss a model or two. The best thing to do to insure that our battery will fit in this case is to ask us.