Before I deployed hundreds of new APX series subscribers, the agreed templates all had "low battery early alert" enabled. The radios operate at full output until they can no longer safely be operated. The "low battery" audible and visual indicators are enabled on FIRE radios, on LAW radios the tones can be silenced IF the user selects the "surveillance" profile. This is sometime required by SWAT/SRT but they are fully aware they must check their gear before deploying on a call. As radio support, we are available and will be on scene with freshly charged/conditioned batteries, chargers, and needed peripherals to support an extended operation. This is the case with many entities of similar size.
In all cases, the APX radio functions at rated power by design and sound the audible "low battery" chrip and visual indications (APX actually shows the words LOW BATT with a RED highlight) until the voltage falls below 6.5 volts, at which time the radio powers off.
After discussing this with two subject matter experts with 60 years of combined actual field work in one of the largest fire rescue agencies in north America with an elite team of communications professionals with decades of experience in actual field work supporting portable radios in IDLH environments, their opinion combined with consultation with stakeholder users all agreed:
WE WANT TO KNOW WHEN OUR EQUIPMENT IS SUBJECT TO FAILING BEFORE IT FAILS OR FAILS TO OPERATE AT RATED SPECIFICATION.
The onus is then on the user and scene command to "lock out/tag out" any equipment indicating it is failing. Our agency SOP is such that, in IDLH settings, no one should be going into an unsafe environment with ANY radio showing a low battery indicator, or SCBA showing a low air condition, or any PAR equipment not registering properly. This is common sense 101 and mirrors NFPA/OSHA best practices and industry standards.
Radios that reduce their power
WITHOUT AUDIBLE AND VISUAL WARNING to extend the battery life are fine for hams, GMRS, or users not operating in an environment where performance is paramount. Inside a burning building, or in a collapsed structure, or out in a rural area, one needs all they can. Any equipment that
IS CAPABLE of being programmed for such is a hazard, especially since this is often the
DEFAULT setting out of the factory. This is a just a piss poor design and should be eliminated from radio operating system (firmware) in future designs/releases. Audible warning is paramount in IDLH settings as users are often unable to see the small "L" on a display (or even see a radio display) in blackout/poor visibility which is commonplace in these conditions.
As was pointed out below, this is a
DANGEROUS, and potentially
DEADLY flaw that can prove to be a false sense of security- in short, if a battery is defective, losing charge where it can't perform to rated specification while under load, or otherwise failing, the
USER SHOULD BE CONSTANTLY ALERTED VISUALLY AND AUDIBLY AND THE USER SHOULD LOCK OUT/TAG OUT SAID RADIO until it can be remedied and verified fit for IDLH service. The user should be stopped from using said radio by the radios operating system not allowing transmission (including registeration on a trunked radio network) by the radio's operating system by that visual and audible alert- this is no different than any other life safety equipment used in public safety such as AEDs, SCBAs, etc.
Performance 'issue' with Icom, Vertex, and many other radio and scanner batteries: A battery with one bad cell will show full charge, then go flat when in TX because the one bad cell will not provide enough volts to keep the radio in full power transmit. Pre-TX volts may be 7.4, then drop under 6.5 in TX, then magically come back. In low volt condition the CPU will shift the transmitter final PA off, meaning that the radio will send a clean signal 50 feet just fine, but no further.
Battery health checks should be performed by users and their support staff no different than they do with SCBA maintenance, AED maintenance, and all other life safety equipment. The IMPRES system from MSI is an excellent way to manage large numbers of batteries and track performance and note those that are nearing end of life. Batteries are relatively inexpensive compared to the cost of subscriber radios, and life is priceless.
Again, we aren't talking about ham/GMRS, we're discussing portable radios used specifically in IDLH and other safety of life operations.
All of the recommendations given for battery testing are great, but only if someone is checking on them. In my experience, portable radios are often ignored when they should be just as important to PM and keep checking on as much as firemen check SCBA and turnout gear, or LEOs check their weapons . I work hard everyday where I work to see that everyone I put my hands on is working the way it's supposed to be. The one time it is truly needed it should not be compromised or fail due to human error or poorly designed radio operating software (firmware) or bad programming.