Battery Safety Guidelines

Have you ever held a battery before? Did you know that a battery though relatively safe can act and operate like a mini bomb? Don’t worry your next battery more than likely will not explode on you if handled correctly. In fact in excess of 100 million battery related devices have been bought by consumer since 2003 (that is a conservative number). So the 339 incidents report by the Consumer Product Safety Commission represent .000003 (a very small percent) of all battery related devices on the market. So the likelihood of your next battery exploding is highly unlikely. However if you ever use a battery or plan on using a battery you should know how to handle and maintain basic battery safety guidelines.  In fact as a general rule of thumb battery packs have to be:

  • Batteries have to be stored safely
  • Batteries have to be charged correctly
  • Batteries have to be protected from unexpected damage
  • Batteries have to be handled safely

Batteries have to be stored safely

Batteries can be stored both indoors and outdoors as long as batteries are kept in cool conditions without direct sun light on the battery or battery storage box or container. Batteries should be stored in a dry location with low humidity, and a temperature range of –20°C to +30°C. Batteries can be stored for a long time however the longer the storage time is the faster the acceleration of the battery’s self-discharge which can lead to the deactivation of the batteries. To minimize the deactivation effect, store battery packs in a temperature range of +10°C to +30°C.  Also if a battery has been stored for a long period of time please note that the deactivation of the batteries may have led to decreased capacity. To recover batteries in this state simply repeat several cycles of fully charging and discharging. Also when storing packs for more than 6 months be sure to charge the battery at least once every 6 months to prevent leakage and deterioration in performance due to self-discharging.

Batteries have to be charged correctly

Batteries must be charged correctly. This means you need to charge your battery with a charger that has the specified voltage and current to correctly charge your battery. You should never attempt reverse charging, since charging a battery with the polarity reversed can cause a reversal in battery polarity, causing gas pressure inside of the battery to rise, which can lead to leakage of the batteries in the pack. Also avoid overcharging. Repeated overcharging can lead to deterioration in pack performance and the battery pack may get over heated. Also note that battery charging efficiency drops at temperatures above 40°C.

Batteries have to be protected from unexpected damage

Batteries, understandably should have some basic protection everyday damage. For example the battery terminals [(+) connector and/or (-) connector] should never be touched or connected to metal wires, necklaces, or chains. Batteries should not be dropped since dropping a  battery will cause the battery to malfunction or puncture. Also batteries should not be twisted or bent. Since any such forced movement will cause the battery to fail.

Batteries have to be handled safely

Furthermore batteries should never be disassembled. Batteries should never be used if an abnormality is detected such as foul odor, deformation, discoloration, bubbling and so on. Battery cells, such as Li-ion or Li-polymer cells should never be reused after removing from the chemistry from the battery pack. Also never touch any liquid coming out of the battery if there is an electrolyte leakage. Also batteries and water should never mix. Once water or moisture gets onto the battery, the battery has the potential to malfunction. In addition never store batteries in hot temperatures 140 degrees Fahrenheit or more. Furthermore do not put batteries into a fire, do not crush, puncture, or nail a battery. Finally never solder directly onto the battery casing or terminals.

Until next time Dan Hagopian –
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Battery Failure Mode and Effects Analysis Part 3

In part 1 and 2 of the article series Battery Failure Mode and Effects Analysis we identified that a battery mode and effects analysis is a procedure for identifying and understanding potential failure modes in a battery system. We found that a battery mode and effects analysis contains four main steps or phases including:

  • Battery Mode Pre-work – explained in part 1
  • Battery Failure Severity – explained in part 2
  • Battery Failure Occurrence – explained in part 2
  • Battery Failure Detection

Now in part 3 of Battery Failure Mode and Effects Analysis I will address Battery Failure Detection and wrap with a summary of the article series.

Battery Failure Detection

Battery failure detection is method of inspection that is used when examining failure modes within a battery system. The method of detecting a battery failure begins with a review of existing system controls that are designed to prevent failure modes. Next comes testing, analysis, and monitoring failures. The purpose of which is to understand why a particular mode is failing. When a failure mode occurs, a detection number that represents the likelihood of detecting a failure mode, is subsequently assigned, and after a series of detections the total number of detection numbers are collected and added together to give a total score of battery failure modes; the lower the detection number is the better the overall battery system design schema.

Remember as in all of the three previous articles it has been noted that the purpose of a battery failure mode and effects analysis is to identify and understand potential failure modes in a battery system. The reason why this is so important is that customers, who provide cash-flow (the lifeblood of a company), must be satisfied. Satisfaction as it relates to batteries is the lowest possible cost while still maintaining the best possible battery product. Thus insuring the lowest possible detection number is critically important to insuring the maximum potential of a company involved in battery design, manufacturing and sales.

Battery Failure Mode and Effects Analysis Summary

Over the last three articles we looked a battery failure mode and effects analysis and learned how helpful this procedure is for analyzing potential failure modes in a battery system. Discovering potential defects in a battery design or manufacturing process is extremely helpful in controlling business expenses and losses as well helping to make more efficient the overall battery development project. A battery failure mode and effects analysis is also closely associated with six sigma methodologies and is a proactive tool for reducing errors, reducing expenses, and increasing profits. Now you could probably find a failure mode and analysis software online or you can build a custom template (that would be my preference) to suit your individual needs. Regardless, simply integrating a battery failure mode and effects analysis into your battery design process, battery manufacturing process, and battery sales process is a valuable tool in helping providing the best possible product to customers.

Until next time Dan Hagopian –
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Battery Failure Mode and Effects Analysis Part 2

A battery mode and effects analysis is a procedure for identifying and understanding potential failure modes in the internal system of a battery. But how do you perform this procedure? In part 1 of this article series we look at the valuable pre-work that lays the ground work for identifying potential problems. In this next portion of the series we learn how to measure failed battery's mode severity and occurrence. To recap we found that a mode and effects analysis contains four main steps or phases including:

  • Battery Mode Pre-work – explained in part 1
  • Battery Failure Severity
  • Battery Failure Occurrence
  • Battery Failure Detection

Battery Failure Severity

Identifying battery failure severity includes an assessment and subsequent severity rating or score of all failed modes and their effects – both direct and indirect. To assess all potential malfunctioning modes in a battery system it is important to notate the battery's designed performance specifications. Knowing upfront how the battery should perform under designed specifications proves to be extremely helpful when determining every potential botched mode.

Potential mode malfunctions could include degradation, warping, incompatibility, misuse or abuse, erroneous algorithms, excessive voltage, improper operating conditions, faulty or weak internal system hardware etc. In addition failing modes have a direct and indirect relationship with an effect. For example the causality of a failed mode could be an electrical short-circuiting, corrosion or deformation.

The causality thus is what needs to be rated with regard to severity. More to the point, each failed mode has a failing effect on the function of the battery system. The effect is user perceived. If the battery user experiences "x" failure effect then the severity of the effect can be rated from 1 to 10 (a severity rating of 10 is the most extreme and is typically reserved for injury to a user).

One note on severity ratings is that there could be a consequential effect of the failed battery on interfacing systems. In another words an improperly performing battery may or may not be wholly contained within its own system. Depending on the severity of the malfunction the effect may go well beyond the battery's system. Conversely and just as important in identifying the cause of the failed battery is the direct and indirect effect of the interfacing system – whereas the interfacing system could be the root cause of a malfunctioning battery.

Battery Failure Mode Occurrence

The next phase of a mode and effects analysis is the occurrence pattern of the failed battery. Simply enough – the occurrence pattern assesses how frequent a failure occurs. Since batteries that fail are looked upon as weak design it is important to know the type, effect, and frequency of a failed battery. This way a design change can be made and money can be saved.

To measure a frequency of a failing mode you can review similar product failure occurrences, processes, or datasheet (if previous examples are available) can be used. Or if previous examples are not available then a trial and error process could be conducted. Why is this important – because if a failed battery is ever rated in the 8-10 zone then you can bet someone is losing life, limb, and or property somewhere. And obviously you would not want to many occurrences at that level of severity.

In part 3 of our article series Battery Failure Mode and Effects Analysis I will wrap up with the final phase which is Battery Failure Detection.

Until next time Dan Hagopian –
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Battery Failure Mode and Effects Analysis Part 1

Have you ever wondered “why” your battery stops working? All batteries fail at one point or another and more importantly all batteries fail – due to different reasons. Specifically, two identical batteries that come from the same manufacturing batch, with the same identical voltage, capacity, and chemistry fail (or stop working) at different times. Why? To understand why batteries fail I will walk through the steps of a battery mode and effects analysis to discover modes of battery failure and the effects of the battery failure.

A battery mode and effects analysis is a procedure for identifying and understanding potential failure modes in a battery system. A battery mode and effects analysis contains four main steps or phases:

  • Battery Mode Pre-work
  • Battery Failure Severity
  • Battery Failure Occurrence
  • Battery Failure Detection

Battery Mode Pre-work

The Battery Mode Pre-work is an essential preliminary component to a battery mode and effects analysis and often times the one component that gets the least attention. It is a way of “starting smart” in the identification of battery failures. As an example, battery failures are often caused by shared interfaces. If an engineer, focused on a single facet of the battery’s micro or macro system, glosses over the effectiveness and efficiency of interfacing components when designing, compiling and assembling a battery’s system, then the failure rate and severity could dramatically increase regardless of how “correct” the engineer’s portion of the system is working. A really good case study on shared interface failures is the battery interface with the device’s operating system. The inefficiency of the operating system’s software in a device can under or over utilize the maximum capacity and voltage of a battery and thus subsequently degrade the battery faster then normal. At the consumer level they would just say the battery is bad or “sucks” when in fact it is the device’s software that is the culprit of faster than normal battery degradation.

Thus careful attention to a battery’s mode pre-work is well advised. Battery mode pre-work includes a complete and detailed description of the battery’s system, the battery’s function, the battery’s intended uses, and the probable unintended uses.

In part 2 of Battery Failure Mode and Effects Analysis I will address Battery Failure Severity and Battery Failure Occurrence.

Until next time Dan Hagopian –
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Buying Batteries: How To Buy A Battery?

We buy batteries first because we need them and then secondly we buy them at the cheapest possible price. Considering that 75% of the world’s batteries are made by Chinese manufacturers, regardless of brand then it makes sense to buy the cheapest battery available knowing full well that I will have to buy another replacement battery sooner rather than later. But who cares as long as it is cheap (buy cheap – buy often)! However if I wanted to make a better battery purchase what considerations would I have to factor? In other words how do I buy a battery that gives me the best value for my dollar?

Swap-meet shopping (that brings back childhood memories) is the ultimate in buying cheap gems. But can I buy a battery at swap-meet prices and be satisfied because I bought the best battery, the longest lasting battery, the best price battery? Buying a battery is not as easy as it first may seem. Most people believe that if you bought an iPod Nano, for example, you would need to buy your battery replacement directly from Apple. Savvy battery shoppers know there is a cheaper and better way of getting their battery replacement. Incidentally Apple does not manufacturer batteries directly – they outsource them to Chinese manufacturers and then affix their own private label to the batteries. Take the private label off and their just like the ones sold by other retailers.

Now before you go out and by your next battery replacement you do need to know a few things including:

  • My Device’s Battery
  • Battery Chemistry, Battery Voltage, and Battery Capacity
  • Battery Price

My Device’s Battery

Your device, be it a PDA, Laptop, iPod, MP3, Camera, Barcode Scanner, Twoway Radio (or any other device) will have a battery that was manufactured  specifically for it. Typically the battery part number will be listed directly on the battery label. The battery part number is often times different from the device’s model number. For example a 167648 battery part number fits the iPAQ 3600 PDA. Interestingly enough the 167648 also fits the IPAQ H3600, IPAQ H3135, IPAQ H3150, IPAQ H3630, H3635, IPAQ H3650, IPAQ H3660, IPAQ H3670, IPAQ H3760, and the IPAQ H3765. In addition to this the 167648 also has alternative or compatible part numbers that is associated with including: COMPAQ DLP 305590, COMPAQ 305590, COMPAQ 3S619-001. This type of numbering sequences within the realm of electronics is quite common as each number though relating to the same device is different due to batch manufacturing, marketing procedures and business management processes. But the same battery, in this case, the 167648 fits with all the numbers above.

In order to buy the right type of battery for your device you must first and foremost know your deice model number. That is actually the best. So if you know you have an iPAQ 3600 then the best way to locate the iPAQ H3630 battery is to search with that model number. If you know your device’s battery part number then that is even better, but at the bare minimum you need to know that you need a battery for an IPAQ H3630. Once you have that information then you can consider the battery’s chemistry, the battery’s voltage, and the battery’s capacity.

Battery Chemistry, Battery Voltage, and Battery Capacity

Next when buying your replacement battery you need to know the battery’s technical ratings. The technical ratings include the battery’s chemistry, the battery’s voltage, and the battery’s capacity. This will get slightly technical but we will go slow and keep the tech lingo at a surface level only.

To begin with a battery is a device that converts chemical energy into electrical energy. The basic design of a battery includes two electrodes, an anode and a cathode. Batteries have two electrodes, an anode (the negative end) and a cathode (the positive end). Collectively the anode and the cathode are called the electrodes. What is positve and what is the negative terminal? It would be great to simply say that the anode is negative and the cathode is positive, however, that is not always the case. Somtimes the opposite is true depending on battery technology. 

In between the battery’s two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either liquid or solid). This battery consisting of two electrodes is called a voltaic cell. To convert chemical energy into electrical energy the battery must contain the chemical base. Common battery chemicals in use today are: Nickel-cadmium batteries, Nickel-metal-hydride batteries, Lead-acid batteries, Lithium-ion batteries, Lithium-ion-polymer batteries, Reusable Alkaline batteries. Choosing your battery’s chemistry is typically not an option since your device’s design was specific to one chemical or another. But it is still good to know what type of chemical is used in your battery.

The other feature that is also not optional to change is your battery’s voltage. Battery voltage is an electrical measure of energy potential. Voltage can be thought of as the amount of "pressure" of electrons that pass from a negative connector to a positive connector. Voltage can also be defined as the Electrical Potential difference – a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. In the fields of electronics the electrical potential difference is the amount of work per charge needed to move electric charge from the second point to the first, or equivalently, the amount of work that unit charge flowing from the first point to the second can perform. Actually voltage is strictly a mathematical product of V= I x R; where V=Voltage, I=Current, R=Resistance. Another words a measurement.

Voltage depending on the type of battery can be measured and is listed on the battery at 3.6V, 2.7V, 7.4V, 14.4V for example. What makes buying a battery difficult, especially when trying to match up the replacement battery’s voltage with your current battery’s voltage is the measurement of nominal voltage. FYI there are a number of different types of voltage including: Float Voltage, Nominal Voltage, Charge Voltage, and Discharge Voltage.

In the case of nominal voltage a device that requires a 3.7V battery will work with a 3.6V battery. But a 12V battery would not do the trick. Another words small voltage deviations are ok – just not big ones.

The final technical rating requirement you will need to know is the battery’s capacity. Battery capacity is a reference to the total amount of energy stored within a battery. Battery capacity is rated in Ampere-hours (AH), which is the product of: AH= Current X Hours to Total Discharge Amperes (commonly "Amps"). Thinking about this another way battery capacity of AH is a measurement of the quantity of the number of electrons passing through a given wire per second. In a single Ampere there are 62,000,000,000,000,000,000 electrons per second! More Amps, More electrons, More current! More is better! So if your existing battery is say 1000 mAh (1 Ah) and your replacement battery 1800 mAh (1.8 Ah) then the 1800 mAh battery offers a higher battery capacity which means your device will run longer. The bigger the capacity the longer your device will run.

Battery Prices

When buying your battery replacement price is something to consider. When considering your price you need to match and compare the technical ratings, the retailers warranty, the retailer’s level of service, the overall value of the retailer. Reading retailers testimonials are good to do as well. Factor in shipping costs and the availability at the retailer for your battery replacement.

Until next time – Dan Hagopian
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