Supply power to radio only when car is running?

[mmckenna]

You haven't lived if you have not experienced a dead car battery at a mountain top repeater site. A Motrac transmitter power supply did the trick in three hours.

I've had this happen at a site, but had another vehicle. No jumper cables at the time. Grabbed some old #6 wire and used that as make shift jumper cables. Could have pulled a 12 volt battery out of the repeater if the other truck wasn't there.

First stop after getting of the mountain was at Home Depot and picked up a set of jumper cables….

 

[robertwbob]

Have you actually measured how much current various radios draw when turned off?

no not even wasting my time doing that.read manual.its shows current draw under load and standby. but if it draws enough to kill a battery in 3 days id say you got trouble as the radio would be warm. and a note computers in 3 months can kill a battery. john deere finally realized that and installed a battery disconnect switch on battery box

 

[cavmedic]

Easy way to address this is to power the radios directly off the battery and use the Lind timer to trigger the ignition sense leads. Since the older Motorola radios I've owned did not have internal timers, this gave me what I needed.

Never had an issue with dead batteries in any of my vehicles caused by radios wired this way.

They are wired that way with charge guards , but the APX still has parasitic draw on the non switched direct wire. No issues with Ambo’s that have battery disconnects when wired to the box batteries , no issues with fire rigs as they also have main disconnects , it seems to be the Ford Exploders / F150 police models. 🤷‍♂️

 

[MUTNAV]

I'm slightly bothered (not much, just to the point of wanting to post about it,... barely)
by the "just remember to do it" responses.

When a distraction happens when you are in the middle of something, a person can easily skip something important. Like parking a car and shutting it off, how often are our minds distracted by something that warrants attention, or by our next task.

Sometimes this happens in situations with more consequences, like when an F-16 pilot doesn't put his gear down because of a radio call to him at the moment he usually puts the gear down.



The second kind of situation is when doing something a little out of the ordinary, like having a radio in your car when you don't normally have it there, or worse case, when you are taking an infant to daycare when it is usually your spouse that does it. LOTS of kids get left in cars because of that. Some parents realize the situation can happen and actually hook up a lanyard from their belt to their childs foot, as a reminder in case they forget. They'll be late for work, but the kid wont die of exposure.

All of this is just human nature.

This is behind a paywall, but if you subscribe to aviation week you can get it.

Fatal Distractions | Aviation Week Network

The deadly loss-of-control accident of a Colgan Air Bombardier DHC-8-400 on Feb. 12, 2009, during a night instrument approach to Buffalo Niagara International Airport again makes it clear that cockpit distractions during critical phases of flight represent a substantial risk to aviation safety...

aviationweek.com

Thanks
Joel

 

[robertwbob]

I'm slightly bothered (not much, just to the point of wanting to post about it,... barely)
by the "just remember to do it" responses.

When a distraction happens when you are in the middle of something, a person can easily skip something important. Like parking a car and shutting it off, how often are our minds distracted by something that warrants attention, or by our next task.

Sometimes this happens in situations with more consequences, like when an F-16 pilot doesn't put his gear down because of a radio call to him at the moment he usually puts the gear down.



The second kind of situation is when doing something a little out of the ordinary, like having a radio in your car when you don't normally have it there, or worse case, when you are taking an infant to daycare when it is usually your spouse that does it. LOTS of kids get left in cars because of that. Some parents realize the situation can happen and actually hook up a lanyard from their belt to their childs foot, as a reminder in case they forget. They'll be late for work, but the kid wont die of exposure.

All of this is just human nature.

This is behind a paywall, but if you subscribe to aviation week you can get it.

Fatal Distractions | Aviation Week Network

The deadly loss-of-control accident of a Colgan Air Bombardier DHC-8-400 on Feb. 12, 2009, during a night instrument approach to Buffalo Niagara International Airport again makes it clear that cockpit distractions during critical phases of flight represent a substantial risk to aviation safety...

aviationweek.com

Thanks
Joel

Let me throw this 1 in. Forget to shut radio off. How the hell can you forget your baby in back seat? If you remember your baby you can remember your baby cause they can sleep quietly.
If you forgot the baby ,you might be better off afoot . Just an observation and never let disattractions detour you in what your doing.

 

[MUTNAV]

Let me throw this 1 in. Forget to shut radio off. How the hell can you forget your baby in back seat? If you remember your baby you can remember your baby cause they can sleep quietly.
If you forgot the baby ,you might be better off afoot . Just an observation and never let disattractions detour you in what your doing.

Easy, as I described, about 12 (or more) deaths a year worth.

There's science behind why parents leave kids in hot cars

As more and more children die in hot cars every summer, parents, politicians and experts are scrambling to find ways to prevent the tragedies.

www.usatoday.com

It's the same reason sometimes landing gears don't get lowered prior to landing, and people sometimes leave coffee, or a package on the roof of their vehicle. It's just how memory works.

Back to radio and power things, it's why reverse feeding a generator into your house is flat out illegal, it could kill a person if not done right and thoughtfully. Systems and procedures that don't care if you are sleep deprived or distracted are the way to go.

Procedures alone wont work in many circumstances, and sometimes can be harmful.

For example: With a truck on the flightline, it's required to be left on and unlocked (among other requirements) when leaving it for a few moments. It was always kind of easy for everyone to remember to leave the truck on, but everyone kept on locking the stupid doors when leaving due to force of habit.

I eventually had to have backup keys made just for this situation.

No reason to not adopt a mechanical system for radio power in a car, or a generator back up for a house.

Thanks
Joel

 

[mikewazowski]

Let's try to stay on-topic for once.

 

[k6cpo]

I find it odd that any ham would have issues with a 12V relay, energised from any car circuit only active when ignition is on. Surely this is a ten minute job, and at most 5 wires?

I did that with the accessory lights on my touring motorcycle. It had a dedicated Accessory circuit I used to energize a relay that then carried the power for the lighting directly from the battery.

With all the modern radios, including HTs, having Auto Power Off settings, I find this unnecessary now.

 

[vagrant]

My XTL5000 is unable to set to auto power off in CPS. Additionally, I like it to be powered on when the vehicle is off at times. The Lind device handles that and whatever else needs help to power down that doesn’t have it built in.

 

[OkieBoyKJ5JFG]

I installed a relay and ran an "add a circuit fuse tap" from the fuse that controls the vehicle's sound system. It turns off when the key is off either after a minute or so, or when you open the door, whichever comes first. It's a little less messy than tapping into a wire somewhere and easier to reverse if something goes wrong.

 

[paulears]

My first radio in a vehicle was 1979. Not once in this time has a radio, on receive, ever flattened the battery enough to not start. I leave the interior light on, leave power banks charging - never an issue. The power drain on receive is tiny!
I'm in the UK where small, easily startable engines are the norm. We don't have much that has high starting torques or capacities over 3 ltrs - where as in the US, don't you have huge engines, with bigger batteries anyway? Direct to battery with a fuse and forget it.

If your battery goes flat overnight with a radio forgetfully left on, it was a faulty battery - look at the amp/hour ratings - a tiny european 40AH battery would run one of my Icoms on receive audio at full for nearly 2 days! I looked up the ones for our biggest engine size cars and it is 5 days!

Is there really a problem here folks?

 

[slowmover]

My first radio in a vehicle was 1979. Not once in this time has a radio, on receive, ever flattened the battery enough to not start. I leave the interior light on, leave power banks charging - never an issue. The power drain on receive is tiny!
I'm in the UK where small, easily startable engines are the norm. We don't have much that has high starting torques or capacities over 3 ltrs - where as in the US, don't you have huge engines, with bigger batteries anyway? Direct to battery with a fuse and forget it.

If your battery goes flat overnight with a radio forgetfully left on, it was a faulty battery - look at the amp/hour ratings - a tiny european 40AH battery would run one of my Icoms on receive audio at full for nearly 2 days! I looked up the ones for our biggest engine size cars and it is 5 days!

Is there really a problem here folks?

Good sized engine, A/C use and short trips. The battery isn’t really getting re-charged adequately. A constant drain ain’t a good idea for long battery life.

And if one lives in the American Siberia (the Great Plains) the hot summer can be offset by extra-cold winters.

— GB & Europe pretty well have the all-around worlds best climate to ensure civilization. Mild

Do you in GB expect to have 40C summer temps 100-day stretches? Overnight lows above 28C? The interior of my vehicles in Texas is routinely 70C on mid-summer afternoons prior to start.

-30C winter isnt unusual near the Canadian border.

Best to keep automobile batteries on a maintainer when parked overnight, radios or not. This is SOP for emergency vehicles despite full-time crewed maintenance.

There’s a difference between, “it’ll start”, and a battery system kept up to desired voltage.


Which one is the luxury car? The Bentley with a dead battery or the decrepit Ford Escort that starts and drives away?


The quality of aftermarket parts has declined. There’s no guarantee (in thinking) that new aftermarket is anywhere near OEM assembly line; a departure from decades past. One or another brand was once a reliable buy.

The OEM Panasonic battery set in my MY-2004 4,100-kg, 5.9L TurboDiesel pickup lasted an astonishing nine-years. Common experience, and some men achieved longer. Never plugged-in. Now? 2-3/years and 5-7 at the outside given charging protocol. Type, design and brand don’t matter.

Radio is fun, certainly, just for starters. Health & Wealth ranks higher. A start system consistently weakened just isn’t good practice where an overall inexpensive device provides insurance.

The half-ton pickups are the best-selling new vehicles here. North of 2.2k-kg, and engines commensurate.


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[mmckenna]

If your battery goes flat overnight with a radio forgetfully left on, it was a faulty battery - look at the amp/hour ratings - a tiny european 40AH battery would run one of my Icoms on receive audio at full for nearly 2 days! I looked up the ones for our biggest engine size cars and it is 5 days!

Is there really a problem here folks?

If it's a single radio, probably not an issue.
Couple of things to consider:
The radio sitting idle uses little current. If it's receiving, it uses more. If it's a trunking radio where it's listening to a control channel, add some more.

If it's a single radio and you leave it sitting for a week or more, then it may be an issue. Easy to do the math and figure out the total current draw.

Some older radios used a lot more current sitting idle, as compared to the newer models.

For me, at work:
Police cars. 2 radios, lighting controller, computer, cameras, cell modem/cradlepoint, plus more. Can easily run down a vehicle battery (or two) if left too long. This is where the timers save the day.

Bus fleet. Several LARGE batteries, one radio. Cameras everywhere, GPS, cellular. Usually not an issue, and the drivers are taught to open the large battery switch when putting the bus up for the night.

But, yes, for the average hobbyist with a single radio, the issue is often a worn out battery and/or failing alternator. The radio just exposes the issue and gets the blame.


For me, personally:
I do this stuff for a living, so adding a Lind timer to the mix is as easy as tying my shoe. Easy to just do it right the first time and not make excuses. Plus, I never know what my wife is going to do. Having the radio in her vehicle turn on automatically is a bit more important than making sure it turns off on its own.

 

[KK4JUG]

What about AGM batteries versus lead-acid ones?

 

[mmckenna]

What about AGM batteries versus lead-acid ones?

What about them?
Some battery types are a bit more tolerant of deep cycling. Some aren't. I've noticed that the last few new vehicles I've had come from the factory with AGM's, probably due to more drain from accessories and smaller engines/starters. Also, power management has improved greatly in modern vehicles.

Old starter batteries didn't tolerate long, slow, deep discharges very well.

 

[slowmover]

What about AGM batteries versus lead-acid ones?

I wouldn’t lay a bet on any of them.
Odyssey and Lifeline included.

Today’s vehicles are software with mechanical bits. Low Voltage is the enemy.

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