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d_studinski

Do I Have To Turn The Hvac, Lights, And Radio Off?

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My company uses a 2010 Toyota Rav4 as a patrol vehicle. This vehicle is started 12-18 times daily and is driven for approximately 2-3 miles each time, at speeds no greater than 20 mph. The vehicle is in use 365 days/yr.

Our vehicle also has a light bar (police lights) mounted on top, that are on whenever the vehicle is running.

We bring our vehicle into a local business for service (Not a Toyota dealership) and I'm concerned that we are possibly being given some incorrect or inaccurate information from them and would like further clarification.

We have been advised that it is necessary to manually turn off the radio, heating and air conditioning, and lights prior to turning the ignition off, as not doing so will cause the Battery to prematurely drain and/or wear out.

All of the components are switched with the ignition itself and are not audibly or visibly "on" when the vehicle is not running.

Is there recommendation necessary to follow, or is this simply a cover for a poor product or service? How long should we reasonably expect a Battery to last under the use conditions I've described above?

Your help would be greatly appreciated, and if you need more information, please do let me know.

Regards,

Dion

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I would have thought that as long as the Battery and alternator were healthy it would cope with that kind of use. The road speed is irrelevant, the alternator will work hard in relation to engine speed. It might be better to force the use of lower gears rather than letting it change up.

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I would have thought that as long as the battery and alternator were healthy it would cope with that kind of use. The road speed is irrelevant, the alternator will work hard in relation to engine speed. It might be better to force the use of lower gears rather than letting it change up.

Yes, but would shutting the radio, hvac, etc, off when the vehicle off have any effect?

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Turning everything off before switching off the engine (and going to ignition switch position where they key can be removed), is fairly good practice and might help slightly but I would have thought the "help" to be negligible.

Things like the radio have a permanently "on" Battery connection, but the current drawn with the engine off and key out is very small (milli to micro amps).

It may depend on what climate you are operating in. 2-3 miles (if the vehicle is diesel) is hardly enough to get the engine warm in cold conditions.

The initial cranking current for the starter motor for a cold engine would be considerably more than with a warm engine. Maybe that is a contributing factor to your Battery life.

You also have additional electrical items fitted (warning lights). Are you sure these do not have some control circuit that is not permanently powered, thus increasing the current drain on the Battery?

Who installed the lights? Did the garage measure the quiescent current drawn by the vehicle when everything is "off"? (Disconnect Battery negative or postive and place an ammeter between the Battery terminal and the lead, probably with doors and bonnet (hood) closed, taking care of the initial ammeter range and that the vehicle is in the state it is normally left when not being used - i.e locked or unlocked).

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Vehicles that are turned into Police patrol vehicles always have upgrades done to the electrics. We see a lot of them and they have uprated fuse boxes, batteries and the like as they are often at the scene of an accident for long periods with lights flashing and radios on. Back in the bad old days, I used to do recovery work and the number of times we would have to help Police with flat batteries was just about every callout, especially in the winter with everything switched on, as in those days, you had an ordinary car with everything bolted on, without much thought about the drain on the Battery. These days, manufacturers upgrade all the charging system and electrics before it is turned into a Police car, Toyota sold a lot of Landcruisers a while back, and we used to service a covert Avensis, ALL of which were uprated in the electrics department. The Avensis used to have a huge box in the boot to carry some special radio gear, it was a proper huge box, we never saw the equipment, just all the plugs and leads, dozens of them, it also had a firearms box inside the car. That particular car had an additional fusebox installed.

I'm thinking this "patrol car" as you put it is actually a standard vehicle and somebody is covering their rrr's just in case the Battery goes flat with all the extra gear on it. If it is a Police car, then I would expect it to be uprated and able to cope

Kingo :thumbsup:

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Yep, good point Mr Kingo. I'd half forgotten about that.

They usually have to pass more severe EMC (Electro-Magentic Compatibility) tests too, because of the comms equipment on board.

However, such use is often considered at design time. e.g. body controllers may have the ability to flash headlamps alternatively, with just the change of a config bit. I won't mention the name of the vehicle maker who had a customer who couldn't stop his headlamps flashing police/ambulance style, due to a corrupted body controller memory.

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Not just Police cars and Ambulances either. Have you ever seen inside one of those VOSA cars? Now those boys carry a lot of gear too, lots of comms and a sort of onboard PC, probably for vehicle checks and owner/operator details

When I were a lad..................go on, take the plish :lol: I worked for a Lucas / Exide agent, and we used to fit batteries to all the emergency vehicles. The Ambulance chaps used to make me smile, the batteries were in the floor in the patient area (think they were Commer vans???) and when they came in, they would have to take the floor up, then remove all the rescue gear :eek: They carried all sorts of ropes and pulleys in the floor for rescues, it would take ages to do and most of the batteries were knackered because nobody could ever be bothered to top them up coz you couldnt get to them!! You don't see that any more :D: :D:

Kingo :thumbsup:

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Commer Vans!!!!!!! Kingo you are going back now. My Dad used to have a Simca van, thought it was the Bees Knees.

Regards Clare

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The place I worked at Clare had a Commer Walkthrough van and a BMC J4, both a heap of junk, my Dad had a few J4's in his day. The diesel ones would never start from cold in the winter and would always have a can of Ezy start in the glove box!

I hated working on any Simca, eeeewwww horrid :lol:

Kingo :thumbsup:

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Of course, a split charge system perhaps may (or may not) help too.

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Good thinking, hadnt thought of that, would be worth a look into if the OP does have a problem with the batteries going flat

Kingo :thumbsup:

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The OP is stateside so maybe a different set up altogether.

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Just on a technical front, my last BMW had to be fully locked to go into "sleep" mode. I found this, to my detriment, when I left the car unlocked, but on a Battery condition gauge for a month, the beggar went flat. Is the RAV a similar system, and does locking the doors shut everything down?

Re the vans, great nostalgia at the Beaulieu Jap weekend, with Commers and J4's a plenty. Happy, but grubby days!!

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Yes, I'm in the US. It's not a police car, all it has is the light bar on top. I just don't see how shutting the radio, lights, and HVAC off manually makes any difference, especially since they're switched with the ignition. Am I missing something here?

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It is well accepted as good practice to shut down all uneccessary electrical circuits before leaving any vehicle. Why - the simple reason is that when the car is next used the firs great demand on the Battery will be the starter motor and the less load on the Battery the less wear and tear on the starter. In other words it needs all the help it can get.

Ther's an old saying in the motor trade. A weak Battery (poor voltage) will cause premature wear to a starter motor and a poor starter will fry a Battery

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….this may be another of those age things but having owned numerous cars for the last 40 years I have always turned lights, radio and heater/fans off before turning off the ignition. This "habit" stems from a few horribly unreliable Ford, Morris and Renault products which were perpetually hard to start even on a warm dry morning.

This habit is so ingrained in me that I’ve passed it on to my daughter who shuts down all the electrical items before turning off the ignition in her almost new MINI

So between a bit of bottom covering by the garrage and what we're calling "best practice" - turn it all off seems to be the message

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