DC Comfort

What is a Battery?

A battery can be any device that stores energy for later use. The word battery is limited to an electrochemical device that converts chemical energy into electricity, by use of a galvanic cell. A galvanic cell is a fairly simple device consisting of two electrodes (an anode and a cathode) and an electrolyte solution. Batteries consist of one or more galvanic cells.
A battery is an electrical storage device. Batteries do not make electricity, they store it. As chemicals in the battery change, electrical energy is stored or released. In rechargeable batteries this process can be repeated many times. Batteries are not 100% efficient – some energy is lost as heat and chemical reactions when charging and discharging. If you use 1000 watts from a battery, it might take 1200 watts or more to fully recharge it. Slower charging and discharging rates are more efficient. A battery rated at 180 amp-hours over 6 hours might be rated at 220 AH at the 20-hour rate and 260 AH at the 48-hour rate. Typical efficiency in a lead-acid battery is 85-95%, in alkaline and NiCad battery it is about 65%.

What is Voltage?

The energy potential from a source that can produce a flow of electricity in a circuit; expressed in volts. In most situations you must select a replacement battery of equal voltage. However, in the more new chemistries such as lithium, voltage resets itself to the requirements of the device. For example, if you are replacing a 14.4 volt laptop battery with a 14.8 volt laptop battery designed for that exact device, the voltage will decrease down to 14.4 volts.

What is Amp/Hour (Ah) Rating stand for ?

Ah basically means the amount of running time that a battery will provide to your device. If your device uses 10 amps, and you use it for 20 minutes, then the amp-hours used would be 10 (amps) multiplied by .333 (hours), or 3.33 AH. So when selecting a battery for your device, you would want to come somewhere near a 3 Ah or more battery. When selecting a replacement battery, it is recommended that you try to match your Ah and voltage. However if you can upgrade to a higher Ah rating, that is ideal. This will mean your running time will increase without harming your device. A slightly lower Ah battery will not noticeably effect running time.

What is Memory Effect?

Memory effect is found in older battery technology, mainly nickel cadium (NiCd) chemistries. What this means is that if a battery is repeatedly only partially discharged before recharging, the battery “forgets” that it has the capacity to further discharge all the way down. To illustrate: If you, on a regular basis, fully charge your battery and then use only 50% of its capacity before the next recharge, eventually the battery will become unaware of its extra 50% capacity which has remained unused. The battery will remain functional, but only at 50% of its original capacity. The way to avoid the dreaded “memory effect” is to fully cycle (fully charge and then fully discharge) the battery at least once every two to three weeks. Batteries can be discharged by unplugging the device’s AC adapter and letting the device run on the battery until it ceases to function.

What is a Smart Battery?

A Smart Battery is one that has a microprocessor within it that collects vital information such as voltage, amperage, time before the battery needs charged, and so on. Must all laptops after the year 2000 have this installed in the batteries. However, on older model laptops, this may not be an option. Smart Batteries do not extend the life or running time of the battery, they simply gather the information mentioned above.

What is CCA?

The cold cranking ampere (CCA) rating refers to the number of amperes a battery can support for 30 seconds at a temperature of 0°F until the battery voltage drops to 1.20 volts per cell, or 7.20 volts for a 12V battery. Thus, a 12V battery that carries a rating of 600 CCA tells us that the battery will provide 600 amperes for 30 seconds at 0°F before the voltage falls to 7.20V.

How long will my battery last?

The life span of a battery will vary considerably with how it is used, how it is maintained and charged, temperature, and other factors.

What is the sulfation of batteries mean?

Sulfation is the formation or deposit of lead sulfate on the surface and in the pores of the active material of the batteries’ lead plates. If the sulfation becomes excessive and forms large crystals on the plates, the battery will not operate efficiently and may not work at all. Common causes of battery sulfation are standing a long time in a discharged condition, operating at excessive temperatures, and prolonged under or over charging.

What is a Starting Battery?

Starting batteries (sometimes called SLI, for starting, lighting, ignition) are commonly used to start and run engines. Engine starters need a very large starting current for a very short time. Starting batteries have a large number of thin plates for maximum surface area. The plates are composed of a Lead “sponge”, similar in appearance to a very fine foam sponge. This gives a very large surface area, but if deep cycled, this sponge will quickly be consumed and fall to the bottom of the cells. Automotive batteries will generally fail after 30-150 deep cycles if deep cycled, while they may last for thousands of cycles in normal starting use (2-5% discharge).

What is a Deep Cycle Battery?

Deep cycle batteries are designed to be discharged down as much as 80% time after time, and have much thicker plates that a standard automotive battery.

What is a Marine Battery?

Marine batteries are considered a “hybrid” battery which actually fall between the starting and deep-cycle batteries. Marine batteries are usually rated using “MCA” or Marine cranking amps which is rated 32 degrees F, while CCA is at zero degree F. (For more information on CCA , CA & MCA, please see below)

What is a Sealed Maintenance Free Battery?

Sealed batteries are known as maintenance free batteries. They are made with vents that (usually) cannot be removed. A standard auto or marine maintenance free battery is sealed, but not fully leak proof. Sealed batteries are not totally sealed since all batteries must allow gas to vent during charging. There are sealed lead acid ( SLA ) batteries that are non-spillable. Please information on our SLA batteries, see AGM and Gel batteries below.

What is the Reserve Capacity rating (RC)?

The reserve capacity of a battery is defined as the number of minutes that it can support a 25 ampere load at 80°F until its terminal voltage drops to 1.75 volts per cell or 10.50 volts for a 12V battery. Thus a 12V battery that has a reserve capacity rating of 100 signifies that it can be discharged at 25 amps for 100 minutes at 80°F before its voltage drops to 10.75 volts.

What is the Marine Cranking rating (MCA)?

The marine cranking ampere (MCA) rating refers to the number of amperes a battery can support for 30 seconds at a temperature of 32°F until the battery voltage drops to 1.20 volts per cell, or 7.20 volts for a 12V battery. Thus, a 12V battery that carries a MCA rating of 600 CCA tells us that the battery will provide 600 amperes for 30 seconds at 32°F before the voltage falls to 7.20V. Note that the MCA is sometimes referred to as the cranking amperes or CA.

What is the HCA rating?

The full form of HCA is hot cranking amperes. It is the same thing as the MCA or the CA or the CCA, except that the temperature at which the test is conducted is 80°F.

What is a MilliAmp Hour (mAh)?

MilliAmp Hour means how much current a battery will discharge over a period of one hour. Higher numbers here reflect a long battery runtime and or higher storage capacity. Higher MAH ratings do not necessarily reflect on speed but more on runtime. For example a 2000 mAh pack will sustain a 2000 milli amp (2 amp) draw for one hour before dropping to a voltage level that is considered discharged. A 1700 will sustain a 1700 mAh (1.7 amp) draw for one hour. 1000 mAH is equal to a 1 Amp Hour (AH) rating.

What is a Watt?

A WATT is the unit for measuring electrical power, i.e., the rate of doing work, in moving electrons by, or against, an electrical potential. Formula: Watts = Amperes x Volts.

What is a Watt-Hour (Watt-Hr, WH)?

A WATT-HOUR is the unit of measure for electrical energy expressed as Watts x Hours.

Can batteries freeze?

In a partially discharged state, the electrolyte in a lead acid battery may freeze. At a 40% state of charge, electrolyte will freeze if the temperature reaches approximately ­16.0°F. The freezing temperature of the electrolyte in a fully charged battery is -92.0°F.

Do batteries self-discharge when not is use?

All batteries, regardless of their chemistry, self-discharge. The rate of self-discharge depends both on the type of battery and the storage temperature the batteries are exposed to. However, for a good estimate, Trojan batteries self-discharge approximately 4% per week at 80°F.

Are lead acid batteries recyclable?

Lead acid batteries are 100% recyclable. Lead is the most recycled metal in the world today. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled waste water uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulfate content is removed as Ammonia Sulfate and used in fertilizers. The separators are often used as a fuel source for the recycling process.

What are Main Batteries?

The main battery (also called the power battery) is the battery pack which allows a laptop or notebook to operate independently of an AC power source. These rechargeable batteries are designed to operate the computer for a certain amount of time (generally 1 to 4 hours).

What are CMOS or Clock batteries?

CMOS & Clock Backup batteries perform the same function in desktop and laptop computers: when the computer is turned off, the battery maintains the time and date, thus insuring their accuracy when the system is once again restarted. More importantly, the battery saves the computers BIOS setup configuration, which allows the system to efficiently reboot once it is restarted. The computer knows what type of hard drive it is dealing with, etc. Not surprisingly, these batteries are known alternatively as CMOS batteries, Real Time Clock (RTC) batteries, or simply internal batteries.

The most common CMOS battery chemistries are Lithium, Nickel Cadmium (NiCad) and alkaline. They are usually somewhere in the 3 to 7.2 volt range and either solder onto the motherboard or plug in via a snap-in connector (depending upon the computer manufacturers design).

In most cases, replacement of the CMOS battery is an easy task. It is simply a matter of locating the battery on the computer’s motherboard, removing it and plugging in a new one. As a rule, internal batteries should be replaced by the same type of battery which was originally used in the machine or according to the manufacturers specifications. The major exception to this rule are older PCs which were manufactured with a NiCad battery soldered onto the motherboard. These computers usually have a three or four pin male plug, with two of the pins connected via a jumper (this is generally found in the same area of the motherboard as the original battery). This plug gives you the option of leaving the soldered battery in place and replacing it with a plug-in lithium or alkaline battery. Removing the jumper tells the computer to ignore the soldered battery and to look to the pins for its power source. If the motherboard has this provision, you can install a standard PC plug-in battery instead of removing the soldered battery and re-soldering a new one (the standard PC plug-in battery is Electro Battery part number BAT 2005 (lithium) or BAT B40 (alkaline). These batteries are interchangeable).

A word of warning: some computers have 4 pins on the motherboard, whereas today’s plug-in batteries come with a 3 pin connector (one of the pinholes is closed in order to prevent the user from inadvertently plugging the battery in with reversed polarity). If this is the case, you should clip the pin from the motherboard that corresponds to the sealed pinhole on the battery plug. That pin is nonfunctional and by clipping it you ensure that future batteries will not be installed on the motherboard with reversed polarity.

IMPORTANT NOTES:
NiCad batteries are rechargeable, whereas Lithium and alkaline batteries are NOT. Therefore, Lithium and alkaline batteries must be replaced by equivalent batteries of the same type. Attempting to replace these non-rechargeable batteries with a NiCad will result in a nonfunctional battery because the computer lacks the proper charging circuitry to charge the NiCad battery.

If a motherboard lacks the above-discussed male pins for an external battery, the NiCad battery MUST be unsoldered and replaced by a NiCad battery ONLY. Attempting to use an alkaline or lithium battery in place of NiCad on such a board could be hazardous. These batteries are not designed to be recharged, and an attempt to do so may cause the battery to “burst”, or explode.
CMOS batteries generally last for two to three years, although some (especially the lithium type) have been known to last much longer. Ironically, the less the computer is used the faster the CMOS battery will run out. This is because when the computer is turned off the battery begins to function. It is recommended to replace the CMOS battery approximately once every two years or when servicing the computer. If the computer has been idle for an extended length of time it is a good idea to change the battery. Changing the battery is a relatively easy and inexpensive task, especially (as were sure many of you out there know) when compared to trying to reboot and configure a computer which has lost its BIOS settings.

What are RAM of Resume batteries?

Some notebook computers are designed with a dedicated battery for backing up RAM (random access memory) functions when the machine temporarily loses power from the main battery. This feature allows users to change the main battery pack without losing the current applications and settings residing in memory. This is called a “battery hot swap” – switching the main battery pack without having to turn off the computer.

These type of batteries are alternately known as bridge batteries, RAM batteries, auxiliary batteries or resume batteries.
Most RAM batteries are rechargeable NiCad or NiMH and will last around 2-3 years. It is recommended that you replace your notebook’s RAM battery when replacing the CMOS battery.

What are the different types of Battery Chemistries?
Batteries in portable consumer devices (laptops and notebooks, camcorders, cellular phones, etc.) are principally made using either Nickel Cadmium (NiCad), Nickel Metal Hydride (NiMH) or Lithium Ion (Li-Ion) technologies. Each type of rechargeable battery technology has its own unique characteristics.

What are some of the major types of lead acid batteries?
Batteries are divided in two ways, by application (what they are used for) and construction (how they are built). The major applications are automotive, marine, and deep-cycle. Deep-cycle includes solar electric (PV), backup power, and RV and boat “house” batteries. The major construction types are flooded (wet), gelled, and AGM (Absorbed Glass Mat). AGM batteries are also sometimes called “starved electrolyte” or “dry”, because the fiberglass mat is only 95% saturated with Sulfuric acid and there is no excess liquid. Flooded may be standard, with removable caps, or the so-called “maintenance free” (that means they are designed to die one week after the warranty runs out). All gelled are sealed and a few are “valve regulated”, which means that a tiny valve keeps a slight positive pressure. Nearly all AGM batteries are sealed valve regulated (commonly referred to as “VRLA” – Valve Regulated Lead-Acid). Most valve regulated are under some pressure – 1 to 4 psi at sea level.

What is an AGM (absorbed glass mat) Battery?

The newer type of sealed non-spillable maintenance free valve regulated battery uses “Absorbed Glass Mats”, or AGM separators between the plates. This is a very fine fiber Boron-Silicate glass mat. These type of batteries have all the advantages of gelled, but can take much more abuse. These are also called “starved electrolyte.” Just like the Gel batteries, the AGM Battery will not leak acid if broken.

What is a Gel Battery?

A gel battery design is typically a modification of the standard lead acid automotive or marine battery. A gelling agent is added to the electrolyte to reduce movement inside the battery case. Many gel batteries also use one way valves in place of open vents, this helps the normal internal gasses to recombine back into water in the battery, reducing gassing. “Gel Cell” batteries are non-spillable even if they are broken. Gel cells must be charged at a lower voltage (C/20) than flooded or AGM to prevent excess gas from damaging the cells. Fast charging them on a conventional automotive charger may be permanently damage a Gel Battery.

What is a NiCad Battery?

Nickel Cadmium (NiCad) is the most popular and durable type of rechargeable battery. They are quick to charge, last approximately 700 charge and discharge cycles, and work well in extreme temperature conditions. Unfortunately, NiCad batteries suffer from “memory effect” if they are not completely discharged each cycle. The memory effect reduces the overall capacity and run time of the battery.

What is a NiMH Battery?

Nickel Metal Hydride (NiMH) batteries do not suffer from the memory effect as the NiCad counterpart. Compared to a NiCad battery of equal size, NiMH batteries run for 30% longer on each charge cycle. They are also made from non toxic metals so they are environmentally friendly. They downside of NiMH technology is the overall battery life. These batteries generally last for 400 charge and discharge cycles.

What is a Lithium Battery?

A type of a battery composed of Lithium, the lightest metal and the metal that has the highest electrochemical potential. Lithium, however, is an unstable metal, so Lithium-Ion batteries are made from Lithium ions from chemicals. Because of its lightness and high energy density, Lithium-Ion batteries are ideal for portable devices, such as notebook computers. In addition, Lithium-Ion batteries have no memory effect and do not use poisonous metals, such as lead, mercury or cadmium. The only disadvantage to Lithium-Ion batteries is that they are currently more expensive than NiCad and NiMH battery packs.

What is a Lithium Ion Battery?

Li-Ion has quickly become the emerging standard for portable power in consumer devices. Li-Ion batteries produce the same energy as NiMH batteries but weigh approximately 35% less. This is crucial in applications such as camcorders or notebook computers where the battery makes up a significant portion of the device’s weight. Another reason Li-Ion batteries have become so popular is that they do not suffer from the memory effect AT ALL. They are also environmentally friendly because they don’t contain toxic materials such as Cadmium or Mercury.