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Jonathan Bastian Batteries and Charging Systems
Get The Picture Newsletter, September 2003
by Jonathan Bastian


Batteries and Charging Systems

Training and Safety:
Batteries and Charging Systems

The old saying is that a chain is only as strong as its weakest link. Your fire department may be training regularly with its thermal imagers, and each member may be quite competent at using the TI while maintaining situational awareness. Your department may even have a TI on every front line company. However, if the TI will not operate when you get on scene, your “chain” of TI proficiency will break. Dead batteries guarantee that your TI will not function on scene.

Performance Expectations

As the power source for your TI, batteries are critical components that must be maintained properly. All rechargeable batteries have some variations, and as the batteries age, their capacities diminish. With properly functioning batteries and chargers, you can expect battery performance close to these nominal levels:

Imager Sensor Battery Life (BL)* BL Transmitting
TI or TIx BST 90 minutes 60 minutes
MX VOx 75 minutes 50 minutes
T3 aSi 150 minutes 100 minutes

* non-transmitting

Evaluation and Investigation

If your performance levels vary significantly from these norms, follow a series of investigative steps to determine the cause of the problem. First, examine the label on the bottom of the battery. If your battery is nickel cadmium (NiCad), you should probably replace it with the nickel metal hydride batteries now standard with all Bullard TIs. NiCad batteries were once the best available technology; however, they will develop a memory. As a result, if the battery is repeatedly recharged prior to being completely discharged, it will essentially lose access to the unused portion, shrinking the capacity of the battery.

Second, try to determine the age of your battery. All rechargeable batteries eventually lose their ability to be recharged, and it is possible that your battery is near the end of its useful service life. Bullard”s rechargeable batteries are rated for 1000 charging cycles; in “firehouse life,” this translates to 18 to 30 months. If you have a battery analyzer available, use it to verify the battery”s storage capacity. The nominal “storage” rating for Bullard batteries is 1600 mAH (milliamp hours), and if your battery is holding less, your battery life will be lower. If your battery is holding less than 1300 mAH, performance will be dramatically impacted, and we recommend you replace the battery.

If you do not have access to a battery analyzer, you can perform an unscientific evaluation. Place the questionable battery in the TI, and activate the unit. If you have a transmitter, activate it as well to speed the process. Run the TI until the LCD screen is blank, and the unit has placed itself into “sleep” mode (the T3 does not have sleep mode; run it until it turns itself off). Recharge the battery completely, then perform the same procedure and time the length of operation. If your battery life is less than 80 percent of the rated life in the chart above, you should replace the battery.

Third, verify that your chargers are performing properly. Place a battery into the charger (or connect the Direct Charge). The LED at the front of the charger will be red to indicate it is charging. If the light blinks red/green, remove the battery and try again. The LED will remain red during the charging process; once the battery is charged, the LED will change to green. Note: if you do not get a red light when you initially place the battery on charge, the battery is not charging! It should take less than 45 minutes to charge one battery; charging two batteries at once should take less than 90 minutes. If your battery indicator is still red after these times, you should use an analyzer to determine the battery”s storage capacity. If the battery indicator is changing to green after just a few minutes, make sure the battery is not overheated, and try again. You may have to analyze or evaluate this battery as mentioned above.

Properly functioning chargers will deliver 12 to 24 volts of direct current. Because vehicle chargers can have wires damaged or loosened due to engine vibration and chassis torsion, they are more susceptible to problems than station chargers. All charger performance can be verified with a voltmeter or multimeter; this tool is available at local electronic stores (such as Radio Shack) for around $20. Charger contacts should be corrosion-free, and should have proper tension and flex to make good contact with the battery. The active contacts in the four-contact chargers are contacts two and four, starting at the left as you look at the LEDs. Contact two is negative; contact four is positive.

Prevention

All of this so far helps identify why you may be encountering battery problems. There are also steps you can take to help prevent battery problems. First and foremost, ensure that your firefighters are properly connecting the batteries and cameras into the charging systems. As mentioned above, if the LED indicators on the charger do not turn red when you insert a battery, then the battery is not charging. While this may seem obvious, it is important that all members understand this. Do not assume that some will learn this on their own; specifically train members on proper charging procedures.

Second, develop a formal system for rotating batteries. This is especially critical if you do not use a vehicle-mounted charger. A formal system is important so that all shifts and all stations use the same process. If Gold shift changes the batteries at the end of a shift, while incoming Red shift swaps batteries at the start of the shift, then one battery is always charged, while the other is never charged! Similarly, if Lt. Smith is the only person who remembers to change batteries, there may be issues when Lt. Smith goes on vacation for three weeks. Volunteer FDs may organize the system around drill nights; career FDs may organize the system around shift changes. Develop a simple system that works easily for your fire department, and remember to communicate the system to all members to ensure they all are on the “same page.”

NiMH batteries have proven themselves ideal for the fire service. While chemical engineers assure us that these batteries will not develop a memory, it is still a good idea to “exercise” your batteries regularly. Consider establishing a monthly practice of completely draining, and then recharging, each battery. A battery conditioner is ideal for this process, but this can also be accomplished by charging and draining the battery as described in the evaluation section. The regular exercise for the battery is good, and it gives you an opportunity to evaluate the battery life. It is always better to learn of battery performance issues while you are at the station, rather than at an incident. Remember to save a fully charged battery for your TI, just in case you need it for a run!

Regular exercise will extend the life of the battery, but eventually it will need to be replaced. Rather than waiting for a battery to become completely useless, establish a plan for replacement. Based on your FD”s activity level, determine roughly how long a battery should last. Add that time to the date you placed the battery in service, and write the future month and year on the battery. Then as part of the regular equipment checks, members can check the “expiration date” just as they would on medications. The month before expiration, contact your Bullard TI distributor to order the new battery. For example, a moderately busy fire department purchased a new T3 in November 2002. The department determines an 18-month replacement schedule is appropriate for them, and therefore writes “May 04” on it. In April 2004, the department will contact the Bullard distributor to order the replacement battery.

Training Issues

Last, your department must address the critical training issues related to battery use. Ensure that your firefighters regularly practice changing batteries in different conditions. Practice with gloves and without, indoors and outdoors, left-handed and right-handed, and in varying light conditions. Members should be comfortable and confident with their ability to properly and promptly change the battery in black-out conditions while wearing firefighting gloves. Remind your members to avoid getting water into the battery compartment, as this can lead to corrosion of the contacts and other technical problems.

All members must train regularly on how to perform and react if they lose the use of the TI for any reason! Even the best maintained batteries could unexpectedly fail. Firefighters need to be proficient in performing a quick equipment check, then resuming their assignment with or without the TI. To practice this, include in your TI training a simulated loss of the TI: remove the battery from the camera about halfway through the evolution, and then ask the team to “evacuate.” This drill emphasizes that your members must maintain mental awareness of where they are in the structure.

Conclusion

If you follow these recommendations, you should be able to diagnose whether you have batteries in need of replacement, as well as ensure that batteries will never be the weak link in your “chain” of TI proficiency.

Use your TI often, wisely and safely.



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