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BATTERIES

We carry a competitive range of U.P.S. and D.C. batteries.

U.P.S. (uninterruptible power supply) sealed lead acid batteries are typically used in fire alarm systems, exit signs, computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, serious business disruption and/or data loss.  The primary role is to provide short-term power when the input power source fails.

 D.C. (deep cycle) batteries are low-maintenance sealed lead-acid rechargeable batteries, typically used in power wheelchairs, electric bikes, mobility scooters and power golf caddies and carts. They should be charged slowly - 8 to 12 hours and must always be stored in a charged state. Leaving the battery in a discharged condition causes sulfation, a condition that makes the battery difficult, if not impossible, to recharge.

SPECIFICATIONS:

Uninterrupted Power Source  Batteries
Battery	Width	Depth	Height *	Weight	Price	Core Charge*	Total
12V4.5AH	90mm/ 3.5"	69mm/ 2.75	100mm/ 4.0"	1.6kg/ 3.5lbs	30.00	1.00	31.00
12V9AH	151mm/ 6.0"	63mm/ 2.5"	100mm/ 4.0"	2.73kg/ 6lbs	40.00	2.00	42.00
12V12AH	151mm/ 6.0"	98mm/ 3.9"	100mm/ 4.0"	4.32kg/ 9.5lbs	50.00	4.00	54.00
Deep Cycle Batteries
12V14AH	151mm/ 6.0"	98mm/ 3.9"	110mm/ 4.3"	5.0kg/ 11lbs	50.00	4.00	54.00
12V20AH	180mm/ 7.1"	76mm/ 3.1"	167mm/ 6.6"	7.0kg/ 15.4lbs	70.00	5.00	75.00
12V28AH	175mm/ 6.9"	166mm/ 6.5"	125mm/ 4.9"	10.9kg/ 24lbs	80.00	8.00	88.00
12V33AH/      U-1	196mm/ 7.7"	135mm/ 5.3"	162mm/ 6.4"	11.2kg/ 25lbs	110.00	10.00	120.00
12V38AH	198mm/ 7.8"	166mm/ 6.5"	175mm/ 6.9"	12kg/ 27lbs	125.00	10.00	135.00
12V55AH/  22NF	250mm/ 9.8"	139mm/ 5.5"	208mm/ 8.2"	18.7kg/ 41lbs	155.00	10.00	165.00
12V75AH/    Grp 24	282mm/ 11.1"	169mm/ 6.7"	207mm/ 8.2"	24.9kg/ 54.8lbs	250.00	10.00	260.00
12V100AH/  Grp 27	331mm/ 13"	169mm/ 6.7"	207mm/ 8.2"	29.8kg/ 65.6lbs	295.00	10.00	305.00
* Height includes battery terminals
* WHAT IS A CORE CHARGE?:  A core charge is a deposit you pay on new batteries, until you return your old batteries. If you do not have the old batteries with you at the time of your purchase, you must pay the core charge. That charge is refunded to you when you return the old batteries. Like a bottle deposit, the charge is designed to encourage recycling.  To receive a core charge refund, either exchange the old part at the time of purchase; OR bring the old/original batteries, along with proof of payment of the core charge in to Mobilityunlimited within 90 days of your purchase. If the recyclable components of the batteries are intact, the core charge will be returned. If they are not, then the customer will not receive a core charge refund.

USING AND PROLONGING THE LIFE OF YOUR BATTERY INVESTMENT

A common reason for motorized machines to stop working or acting erratically is battery failure. Taking proper care of them is very important. Mobility machine batteries are different from car batteries. Deep cycle batteries are charged once a day and supply large amounts of electricity while running. The life of a battery depends on how heavily it is used. Batteries can last over 2 or 3 years when properly maintained.

It is a misconception among owners of electric scooters, e-bikes, golf machines and wheelchairs that batteries should be completely discharged before recharging.

SIX EASY STEPS FOR MAINTAINING SEALED LEAD ACID BATTERIES

1. Avoid heavily discharging the batteries.

2. Use the charger supplied with your machine and make sure, if equipped, it is set to the proper battery type.

3. If you need to store your batteries for a period of time, it is best to charge them at least every 8 weeks.

4. New batteries require conditioning for the first 5 to 10 charging cycles to reach full power.

5. Do not use automotive battery chargers unless they have a setting for Sealed Batteries.

6. Always charge batteries after use.

SEALED BATTERIES

Sealed batteries require no maintenance other than keeping the terminals free of corrosion. Most airlines only allow sealed batteries. These batteries are available through MobilityUnlimited and other quality suppliers.   (MobilityUnlimited Inc.....clean green machines)

HOW LEAD ACID BATTERIES WORK by Constantin von Wentzel*

Here is a short run-through of how lead-acid batteries work. Start with some basics and work your way up - hence the absence of an alphabetical order. Depending on your familiarity with the subject, you may want to scroll down more or less.

Voltage   Voltage is an electrical measure which describes the potential to do work. The higher the voltage, the greater its risk to you and your health. Systems that use voltages below 50V are considered low-voltage and are not governed by as strict (some might say arcane) set of rules as high-voltage systems.

Current    Current is a measure of how many electrons are flowing through a conductor. Current is usually measured in amperes (A). Current flow over time is defined as ampere-hours (a.k.a. amp-hours or Ah), a product of the average current and the amount of time it flowed.

Power     Power is the product of voltage and current and is measured in Watts. Power over time is usually defined in Watt-hours (Wh), the product of the average number of watts and time. Your energy utility usually bills you per kiloWatt-hour (kWh), which is 1,000 watt-hours.

What is a Lead-Acid Battery?    A lead-acid battery is a electrical storage device that uses a reversible chemical reaction to store energy. It uses a combination of lead plates or grids and an electrolyte consisting of a diluted sulphuric acid to convert electrical energy into potential chemical energy and back again. The electrolyte of lead-acid batteries is hazardous to your health and may produce burns and other permanent damage if you come into contact with it. Thus, when dealing with electrolyte protect yourself appropriately!

Deep Cycle vs. Starter Batteries     Batteries are typically built for specific purposes and they differ in construction accordingly.

Broadly speaking, there are two applications that manufacturers build their batteries for: Starting and Deep Cycle.

•  As the name implies, Starter Batteries are meant to get combustion engines going. They have many thin lead plates which allow them to discharge a lot of energy very quickly for a short amount of time. However, they do not tolerate being discharged deeply, as the thin lead plates needed for starter currents degrade quickly under deep discharge and re-charging cycles. Most starter batteries will only tolerate being completely discharged a few times before being irreversibly damaged.

• Deep Cycle batteries have thicker lead plates that make them tolerate deep discharges better. They cannot dispense charge as quickly as a starter battery but can also be used to start combustion engines. You would simply need a bigger deep-cycle battery than if you had used a dedicated starter type battery instead. The thicker the lead plates, the longer the life span, all things being equal. Battery weight is a simple indicator for the thickness of the lead plates used in a battery. The heavier a battery for a given group size, the thicker the plates, and the better the battery will tolerate deep discharges.

• Some "Marine" batteries are sold as dual-purpose batteries for starter and deep cycle applications. However, the thin plates required for starting purposes inherently compromise deep-cycle performance. Thus, such batteries should not be cycled deeply and should be avoided for deep-cycle applications unless space/weight constraints dictate otherwise.

Regular versus Valve-Regulated Lead Acid (VRLA) Batteries      Battery Containers come in several different configurations. Flooded Batteries can be either the sealed or open variety.

• Sealed Flooded Cells are frequently found as starter batteries in cars. Their electrolyte cannot be replenished. When enough electrolyte has evaporated due to charging, age, or just ambient heat, the battery has to be replaced.

• Deep-Cycle Flooded cells usually have removable caps that allow you to replace any electrolyte that has evaporated over time. Take care not to contaminate the electrolyte - wipe the exterior container while rinsing the towel frequently.

• VRLA batteries remain under constant pressure of 1-4 psi. This pressure helps the recombination process under which 99+% of the Hydrogen and Oxygen generated during charging are turned back into water. The two most common VRLA batteries used today are the Gel and Absorbed Glass Mat (AGM) variety.

• Gel batteries feature an electrolyte that has been immobilized using a gelling agent like fumed silica.

• AGM batteries feature a thin fiberglass felt that holds the electrolyte in place like a sponge.
  
  Neither AGM or Gel cells will leak if inverted, pierced, etc. and will continue to operate even under water.

Battery Cells    Battery Cells are the most basic individual component of a battery. They consist of a container in which the electrolyte and the lead plates can interact. Each lead-acid cell fluctuates in voltage from about 2.12 Volts when full to about 1.75 volts when empty. Note the small voltage difference between a full and an empty cell (another advantage of lead-acid batteries over rival chemistries).

Battery Voltage    The nominal voltage of a lead-acid battery depends on the number of cells that have been wired in series. As mentioned above, each battery cell contributes a nominal voltage of 2 Volts, so a 12 Volt battery usually consists of 6 cells wired in series.

State of Charge    The State of Charge describes how full a battery is. The exact voltage to battery charge correlation is dependent on the temperature of the battery. Cold batteries will show a lower voltage when full than hot batteries. This is one of the reasons why quality alternator regulators or high-powered charging systems use temperature probes on batteries.

Depth of Discharge (DOD)    The Depth of Discharge (DOD) is a measure of how deeply a battery is discharged. When a battery is 100% full, then the DOD is 0%. Conversely, when a battery is 100% empty, the DOD is 100%. The deeper batteries are discharged on average, the shorter their so-called cycle life.

For example, starter batteries are not designed to be discharged deeply (no more than 20% DOD). Indeed, if used as designed, they hardly discharge at all: Engine starts are very energy-intensive but the duration is very short. Most battery manufacturers advocate not discharging their batteries more than 50% before re-charging them.

Battery Storage Capacity    The Amp-hour (Ah) Capacity of a battery tries to quantify the amount of usable energy it can store at a nominal voltage. All things equal, the greater the physical volume of a battery, the larger its total storage capacity. Storage capacity is additive when batteries are wired in parallel but not if they are wired in series.

Most marine, automotive, and RV applications use 12V DC. You have the choice to either buy a 12V battery or to create a 12V system by wiring several lower-voltage batteries/cells in Series.

When two 6V, 100Ah batteries are wired in Series, the voltage is doubled but the amp-hour capacity remains 100Ah (Total Power =1200 Watt-hours).

You may decide to wire batteries in series because a single 12V battery with the right storage capacity is simply too heavy, unwieldy, or awkward to lift into place. Batteries consisting of fewer cells (and hence lower voltage) in series can provide the same storage capacity yet be portable. It is not unusual to see solar power installations where the battery bank consists of a sea of 2V batteries that have been wired in series.

Two 6V, 100Ah batteries wired in Parallel will have a total storage capacity of 200Ah at 6V (or 1200 Watt-hours).

Battery banks consisting of 12V batteries wired in parallel are often seen on OEM installations in boats and RVs alike. Such banks are simple to wire up and require a minimum of cabling. However, the wiring must have the capacity to deal with a full battery bank.

You should fuse each battery individually in such a bank to ensure that a battery gone bad will not affect the rest of the bank.

Battery banks wired in Series-Parallel are even more complicated. Here, four 6V cells are wired in two "strings" of 12VDC that were then wired in parallel. Using 6V, 100Ah batteries, this system will have a storage capacity of 200Ah at 12V or 2,400Wh.

Since such a system has more wiring, it is very important to group 'strings" logically and to label everything.
Furthermore, it is a very good idea to fuse every "string" of series-wired batteries to ensure that a problem in one part of the battery bank does not take the whole bank down.

We use Group GPL4C batteries exclusively on our boat. Since these batteries have a nominal voltage of 6V, we have wired them in series for the starter bank (2 batteries) and series-parallel for the house
bank (4 batteries).

Despite advances in instrumentation, the battery industry mostly still advertises amp-hours as a capacity measure instead of watt-hours. Hopefully, the battery and marine power instrumentation industry will make a transition to Watt-hours (Wh) in the future.

Since batteries depend on a chemical reaction to produce electricity, their Available Capacity depends in part on how quickly you attempt to charge or discharge them relative to their Total Capacity. The Total Capacity is frequently abbreviated to C and is a measure of how much energy the battery can store. Available Capacity is always less than Total Capacity.

Typically, the amp-hour capacity of a battery is measured at a rate of discharge that will leave it empty in 20 hours (a.k.a. the C/20 rate). If you attempt to discharge a battery faster than the C/20 rate, you will have less available capacity and vice-versa. The more extreme the deviation from the C/20 rate, the greater the available (as opposed to total) capacity difference.

However, as you will discover in the next section, this effect is non-linear. The available capacity at the C/100 rate (i.e. 100 hours to discharge) is typically only 10% more than at the C/20 rate. Conversely, a 10% reduction in available capacity is achieved just by going to a C/8 rate (on average). Thus, you are most likely to notice this effect with engine starts and other high-current applications like inverters, windlasses, desalination, or air conditioning systems.

For example, the starter in an engine will typically quickly outstrip the capacity of the battery to keep cranking it for any length of time. Hence the tip from mechanics to wait some time between engine start attempts. Not only does it allow the engine starter to cool down, it also allows the chemistry in the battery to "catch-up". As the battery comes to a new equilibrium, its available capacity increases. A very elegant equation developed in 1897 by a scientist called Peukert describes the charging and discharging behavior of batteries.

As you can see below, the Peukert equation consists of several factors.
Peukerts Equation: Iⁿ x T = C where
· I is the current (usually measured in amperes)
· T is time (usually measured in hours)
· n is the Peukert number / exponent
  C is the theoretical storage capacity of the battery (usually measured in amp-hours). Use the C/100 capacity or add 10% to the storage capacity at the C/20 rate.

As you can see, the available current is dependent on the rate of discharge and the Peukert exponent for the battery. The closer the exponent is to 1 (one), the less the available capacity of a battery will be affected by fast discharges. Peukerts numbers are derived empirically and are usually available from manufacturers. They range from about 2 for some flooded batteries down to 1.05 for some AGM cells. The average peukerts exponent is 1.2 though the exact number depends on the battery construction and chemistry.

The following image shows the dramatic impact of the Peukerts exponent on the available capacity of a 120Ah battery, depending on the ampere draw. As you can see, the lower the Peukerts Exponent, the lesser the effect on available capacity. Note the dramatic difference in Available Capacity between the average flooded cell (n = 1.20) and a deep cycle AGM (n = 1.08) with high-current applications.

In the above picture, note how the low exponent battery (topmost curve) has more than four times the available capacity over a high-exponent battery (lowest curve). This chart uses a linear scale.

When the time comes to charge a battery, the Peukerts effect also comes into play. The capacity of a battery to absorb a charge during the bulk phase is also dependent on it's Peukerts number. This is one of the reasons why AGM cells can be bulk charged at much higher rates than either Gel or Flooded cells.

Reserve Minutes

Reserve Minutes are a measure of how long your battery can sustain a load before it's available capacity has been completely used up. This measure is especially useful for folks who want to run inverters, fridges, and other large loads. The following chart has a logarithmic time scale (minutes) - hence, the non-linear nature of the Peukert effect is smoothed out quite a bit.

Note how batteries that have a high Peukerts Exponent will quickly run out of capacity with high loads. Here, the low-exponent battery will last over 100 minutes with a 50 ampere load, while the high-exponent battery will last about 20 minutes. Thus, anytime you deal with large loads relative to the battery capacity available, chose a low-exponent battery. This is why many wheel-chairs and other electrically motorized vehicles use AGMs.

This chart answers why starter batteries are built to have a low Peukerts exponent. Otherwise, they'd simply not be able to crank an engine for more than a few seconds. However, the thin plates that allow flooded cells to work as starter batteries also make them too fragile for deep-cycle use.

Conversion Efficiency

The conversion efficiency denotes how well a battery converts an electrical charge into chemical energy and back again. The higher this factor, the less energy is converted into heat and the faster a battery can be charged without overheating (all other things being equal). The lower the internal resistance of a battery, the better its conversion efficiency.

One of the main reasons why lead-acid batteries dominate the energy storage markets is that the conversion efficiency of lead-acid cells at 85%-95% is much higher than Nickel-Cadmium (a.k.a. NiCad) at 65%, Alkaline (a.k.a. NiFe) at 60%, or other inexpensive battery technologies

Battery manufacturers define the end-of-life of a battery when it can no longer hold a proper charge (for example, a cell has shorted) or when the available battery capacity is 80% or less than what the battery was rated for. The life of Lead Acid batteries is usually limited by several factors:

■ Cycle Life is a measure of how many charge and discharge cycles a battery can take before its lead-plate grids/plates are expected to collapse and short out. The greater the average depth-of-discharge, the shorter the cycle life.

■ Age also affects batteries as the chemistry inside them attacks the lead plates. The healthier the "living conditions" of the batteries, the longer they will serve you. Lead-Acid batteries like to be kept at a full charge in a cool place. Only buy recently manufactured batteries, so learn to decipher the date code stamped on every battery... (inquire w/manufacturer). The longer the battery has sat in a store, the less time it will serve you! Since lead-acid batteries will not freeze if fully charged, you can store them in the cold during winter to maximize their life.

■ Construction has a big role in battery life too, some designs are better at preserving batteries than others and the suitability of a design for a given application plays a role also. For example, flooded lead-acid cells will typically fare worse than their VRLA brethren in operations that involve a lot of jerky motion - the immobilized plates in VRLA cells will be stressed less than suspended plates in cheap flooded cells.

■ Plate Thickness helps - the thicker the plates, the more abuse, charge and discharge cycles they can take. Thicker plates will also survive any equalization treatments for sulphation better. The heavier the battery for a given group size, the thicker the plates are, so you can use weight as one guide to buying lead-acid batteries.

■ Sulphation is a constant threat to batteries that are not fully re-charged. A layer of lead sulphate can form in these cells and inhibit the electro-chemical reaction that allows you to charge/discharge batteries. Many batteries can be saved from the recycling heap if they are Equalized In closing, the design life of a battery depends in part on its construction, its type, the thickness of the plates, its charging profiles, etc. All these factors come together to determine just how long your battery may ultimately serve you.

Equalization
Sulphation layers form barrier coats on the lead plates in batteries that inhibit their ability to store and dispense energy. The equalization step is a last resort to break up the Sulphate layers using a controlled overcharge. The process will cause the battery electrolyte to boil and gas, so it should be only done under strict supervision and with the proper precautions.

Gassing
Batteries start to gas when you attempt to charge them faster than they can absorb the energy. The excess energy is turned into heat, which then causes the electrolyte to boil and evaporate. The evaporated electrolyte can be replenished in batteries with removable caps such as most flooded deep-cycle batteries. Many car batteries are sealed and thus need to be replaced when their electrolyte evaporates over time.

Since AGM and Gel cells are always sealed, it is very important to guarantee they are not overcharged. The only way to ensure this is to use a temperature-compensated charging system. Such chargers use a temperature probe on the battery to ensure that the battery does not get too hot. As the battery heats up, the charging current is reduced to prevent thermal runaway, a very dangerous condition.

Thermal Runaway
This is a very dangerous condition that can occur if batteries are charged too fast. One of the byproducts of Gassing are Oxygen and Hydrogen. As the battery heats up, the gassing rate increases as well and it becomes increasingly likely that the Hydrogen around it will explode. The danger posed by high Hydrogen concentrations is one of the reasons that the American Boat and Yachting Council (ABYC) requires that batteries be installed in separate, well-ventilated areas.

Self-Discharge
The self-discharge rate is a measure of how much batteries discharge on their own. The Self-Discharge rate is governed by the construction of the battery and the metallurgy of the lead used inside.

For instance, flooded cells typically use lead alloyed with Antimony to increase their mechanical strength. However, the Antimony also increases the self-discharge rate to 8-40% per month. This is why flooded lead-acid batteries should be in use often or left on a trickle-charger.

The lead found in Gel and AGM batteries does not require a lot of mechanical strength since it is immobilized by the gel or fiberglass. Thus, it is typically alloyed with Calcium to reduce Gassing and Self-Discharge. The self-discharge of Gel and AGM batteries is only 2-10% per month and thus these batteries need less maintenance to keep them happy.

To further complicate matters, manufacturers for marine batteries make them in all sorts of sizes and voltages. Battery case sizes are typically denoted by a "Group Size" which has nothing to do with the actual size of the battery. For example, Group 8D batteries are much larger than Group 31 batteries. Here are some examples:

The group size will merely indicate the approximate exterior dimensions (including terminals) and voltage of the battery in question. However, the exact dimensions can only be directly obtained from each manufacturer.

Now that you are familiar with the lingo, click HERE for the differences between the various types of lead-acid batteries.

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Can the lead-acid battery compete in modern times? by Isidor Buchmann

The answer is YES. Lead-acid is the oldest rechargeable battery in existence. It has retained a market share in applications where newer battery chemistries would either be too expensive or the upkeep would be too demanding. There are simply no cost-effective alternatives for such applications as wheelchairs, scooters, golf carts, people movers and UPS systems.

Invented by the French physician Gaston Planté in 1859, lead-acid was the first rechargeable battery for commercial use. Today, the flooded lead-acid battery holds a domineering position in automobiles, forklifts and large uninterruptible power supply (UPS) systems.

During the mid 1970s, researchers developed a maintenance-free lead-acid battery that could operate in any position. The liquid electrolyte was transformed into moistened separators and the enclosure was sealed. Safety valves were added to allow venting of gas during charge and discharge.

Driven by different market needs, two lead-acid systems emerged: the small sealed lead-acid (SLA), also known under the brand name of Gelcell, and the large valve-regulated-lead-acid (VRLA). Technically, both batteries are the same. (Engineers may argue that the word 'sealed lead acid' is a misnomer because no rechargeable battery can be totally sealed.)

Unlike the flooded lead acid battery, both SLA and VRLA are designed with a low over-voltage potential to prohibit the battery from reaching its gas-generating potential during charge. Excess charging would cause gassing and water depletion. Consequently, these batteries can never be charged to their full potential.

Finding the ideal charge voltage limit is critical. Any voltage level is a compromise. A high voltage limit (above 2.40V/cell) produces good battery performance but shortens the service life due to grid corrosion on the positive plate. The corrosion is permanent. A low voltage (below 2.40V/cell) is safe if charged at a higher temperature but is subject to sulfation on the negative plate.

Lead-acid is not subject to memory. Leaving the battery on float charge for a prolonged time does not cause damage. The self-discharge is about 40% per year, one of the best on rechargeable batteries. In comparison, nickel-cadmium self-discharges this amount in three months. Lead-acid is relatively inexpensive to purchase but the operational costs can be more expensive than the nickel-cadmium if full cycles are required on a repetitive basis.

Lead-acid does not lend itself to fast charging. Typical charge time is 8 to 16 hours. The battery must always be stored in a charged state. Leaving the battery in a discharged condition causes sulfation, a condition that makes the battery difficult, if not impossible, to recharge.

Unlike nickel-cadmium, the lead-acid does not like deep cycling. A full discharge causes extra strain and each cycle robs the battery of a small amount of capacity. This wear-down characteristic also applies to other battery chemistries in varying degrees. To prevent the battery from being stressed through repetitive deep discharge, a larger battery is recommended.

Depending on the depth of discharge and operating temperature, the sealed lead-acid provides 200 to 300 discharge/charge cycles. The primary reason for its relatively short cycle life is grid corrosion of the positive electrode, depletion of the active material and expansion of the positive plates. These changes are most prevalent at higher operating temperatures. Cycling does not prevent or reverse the trend.

The optimum operating temperature for the lead-acid battery is 25°C (77°F). As a guideline, every 8°C (15°F) rise in temperature will cut the battery life in half. VRLA, which would last for 10 years at 25°C (77°F), will only be good for 5 years if operated at 33°C (95°F). Theoretically the same battery would endure a little more than one year at a desert temperature of 42°C (107°F).

Among modern rechargeable batteries, the lead-acid battery family has the lowest energy density, making it unsuitable for handheld devices that demand compact size. In addition, performance at low temperatures is poor.

The sealed lead-acid battery is rated at a 5-hour discharge or 0.2C. Some batteries are rated at a slow 20-hour discharge. Longer discharge times produce higher capacity readings. The lead-acid performs well on high load currents. During these pulses, discharge rates well in excess of 1C can be drawn.

In terms of disposal, the lead-acid is less harmful than nickel-cadmium but the high lead content and the electrolyte make the lead-acid environmentally unfriendly.

Advantages
°  Inexpensive and simple to manufacture.
°  Mature, reliable and well-understood technology - when used correctly, lead-acid is durable and provides   dependable service.
°  The self-discharge is among the lowest of rechargeable battery systems.
°  Low maintenance requirements - no memory; no electrolyte to fill on sealed version.
°  Capable of high discharge rates.
 

Limitations
°  Low energy density - poor weight-to-energy ratio limits use to stationary and wheeled applications.
°  Cannot be stored in a discharged condition - the cell voltage should never drop below 2.10V.
°  Allows only a limited number of full discharge cycles - well suited for standby applications that require only occasional deep discharges.
°  Lead content and electrolyte make the battery environmentally unfriendly.
°  Transportation restrictions on flooded lead acid - there are environmental concerns regarding spillage.

°  Thermal runaway can occur with improper charging.

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About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Vancouver BC. Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. Award winning author of many articles and books on batteries, Mr. Buchmann has delivered technical papers around the world.
Cadex Electronics is a manufacturer of advanced battery chargers, battery analyzers and PC software. For product information please visit www.cadex.com.
 

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