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Battery or gizmo's

E

edgeoftime

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Location
Waltham Abbey Essex
Car
11 idtec tourer ex.
Any one throw a light on this (pardon the pun) The other week I parked up and left the side lights on in error, on return to car, idtec 2011, 8 hours later the battery was flat as a you know what, The other day I got phone call from the Mrs she too had left the lights on on her Jazz for about 6 hours and yes the battery was flat, manage to get her started by jumping from the accord. I seem to recall in the bad old days that cars had to be parked on streets with obligatory lights on all night, or during the hours of darkness and most would start up next morning. Is it the draw of the bulbs or the silly squeaky warning that sounds doing the damage? IMHO there are too many alarms on these modern motors, i.e. key in ignition, door open, seat belt not fastened boot/tailgate not shut, the list is endless. Or am I being too argumentative.
 
The Diesels tend to require a hefty amount of current to power up the glow plugs upon a cold start, thats why the batteries in the diesels have a quite large capacity. Around 780 CCA.
A normal petrol car is around 360 CCA.
The alarm chime when leaving your lights on wouldnt consume too much current but it would also depend how many tail lights you have too.
but having said that I would still think the glow plug power requirement upon a cold start would be the issue in this case.

If your diesel was a petrol car with that battery capacity i reckon it wouldn't have any issues starting.

The glow plugs on a diesel are a killer upon a cold start.

Having said that, the Jazz's battery is extremely small producing around 330 CCA. Quite a joke really so leaving its side lights on will drain it fairly quickly.
 
Capacity is not measured by CCA. It is measured by ampere-hours, Ah.

CCA is cold cranking amps, the current that battery can provide in about zero Celsius (0 C). Diesel starter motors a heavily depend on this, because the engine is much heavier, and also in the cold, it is much difficult to spin it.

For diesel application, i will go for a biggest CCA @ smallest Ah.
2.2 iDTEC engine can accommodate 77Ah @ 780 A, there is also a 80Ah witch have 750/740A, which i do not see the point to buy this.

petrol cars do not need high ampere-cranking battery, so they tend to be a lot smaller, because engines a lighter and it is easier to crank it.

the bigger the battery, the longer will take time to recharge it.
the bigger the battery, the longer will take time to discharge it also, so if you found your car with a dead battery there several options:
1: parasitic drain (bigger than 0,02A drain during car sleep),
2: left lights on (parking/dim lights), lights can drain the biggest battery during the night.
3: dead battery itself (you need to take your battery, to run some test to prove it).
 
HI,
the reason that a diesel engine requires more from the battery on start-up, is because the compression ratio of a diesel engine is much greater than a petrol engine.

Modern petrol engines have a compression ratio of about 10:1, where as diesels are about 16:1 for a turbo and as much as 22:1 for non turbo versions.

More compession means - more resistance to the engine turning over - means greater effort required of the starter - hence more starter current required from a larger battery.


Common rail diesel engines (as in iDTEC) do not require the use of glow plugs until the temperature drops to about -30C.

My advice is to insert the key and immediately start the engine this helps to protect the battery life.

Pete.
 
Rubbish!! how do you expect a diesel to start without preheating? Do as you do and the battery will be knackered in no time. Especially as the temperature in the oncoming weeks is going to get a lot colder. Read my first post, I want to know why leaving the "obligatory" lights on for 7 hours is enough to flatten the battery.
 
Yes, i think it is enough...

For a preheating, i also do not agree, in modern BMWs preheating occurs when you unlock a car and open drivers doors, so you never seeing a glow plug symbol, because it is already preheating. This method is for smoother engine running and of course for better start up.

If outside is -15, the engine is cold, even with a compresion ratio that big, the fuel cant heat up as much as with glow plugs to explode. Preheating is a must. Also it is required a lot of current for those hot plugs
 
Hi,
John Hamer asks:-

"I want to know why leaving the "obligatory" lights on for 7 hours is enough to flatten the battery."

See if this explanation satisfies you.

With the side lights on you have 2 x 5watt bulbs at the front, 4 tail light bulbs at the rear 4 x 5watt and 2 number plate lights 2 x 5 watt, with a total of 8 x 5watts = 40 watts ( there are several small lights on the dash etc, these may be only LEDs I am not sure so I will ignor them)
The current drain is therefore at least 3.33 amps. If you leave them on for 7 hours this is at least 23.1 ampere hours.

The battery on iDTEC is rated at 74 ampere hours but this will only be true when the battery is new and fully charged. In general running conditions the charge may only be 75% this will depend on the type of running (short/long journeys, Summer or Winter) and in cold weather the battery charge will take a big hit due to headlights, seat heaters, rear window demist, wipers front and rear, heater fan etc.

To add to this, as the battery ages it looses its capacity to hold a charge and eventually will not hold a charge overnight. The accepted battery life is said to be about 6 years.

So you probably had a battery that was say 75% fully charged, about 55 ampere hours, and you drained 23.1 ampere hours from it leaving only about 32 ampere hours, or only 43% capacity of a new, fully charged battery,

This is probably reason why it would not start the car.

With regard to the glow plugs, try starting the car immediatly after inserting the key. If it starts straight away (as mine does) the the glow plugs were not required. If it fails to start you have some kind of starting problem with your car.

Pete.
 
I bow to your superior knowledge, but in my case not only was the battery flat I could not even open the door with the fob!! I needed to insert the key into the door lock "drivers" side, and having got in I could not open any other door, I still say that jumping into our diesels and turning the key for a start without pre heating is a bad thing. Also and I stand to be corrected on this is there not a heating element in the fuel line? With our old ford 6D'S we use a paint stripper straight into inlet manifold, and on our old perkins fork lift a gas fitters soldering torch. some people even light a bonfire under the engine. I will see how I go during this cold snap we are having, and if it fails to start I will get a new battery, rather than having a VIKING FUNERAL on the drive.
 
edgeoftime said:
I bow to your superior knowledge, but in my case not only was the battery flat I could not even open the door with the fob!! I needed to insert the key into the door lock "drivers" side, and having got in I could not open any other door, I still say that jumping into our diesels and turning the key for a start without pre heating is a bad thing. Also and I stand to be corrected on this is there not a heating element in the fuel line? With our old ford 6D'S we use a paint stripper straight into inlet manifold, and on our old perkins fork lift a gas fitters soldering torch. some people even light a bonfire under the engine. I will see how I go during this cold snap we are having, and if it fails to start I will get a new battery, rather than having a VIKING FUNERAL on the drive.

Apologies Pete, very cold this morning, opened door inserted key and immediately went to start and hey presto she fired up straight away. Wonderful thing this technology.
Click to expand...
 
Yes in older applications, without commonrail systems there was no glow plugs as such, the heating occurred in intake chamber where diesel with air was already mixed up.

Today we have a commonrail engines (N22B (i-DTEC) and N22A (i-CTDi)) where mixing (sort of) never happens.
So there was introduced a glow plugs into each cylinder.
The explosion happens when piston reaches top dead center with only air compressed, when airs is compressed the temperature rises, and when the piston is in TDC the pressure in commonrail is near about 1800bar, through injector sprays, and fuel in hot chamber ignites and explodes. This is referring like 'direct infection' application.
The glow plugs parts is here to heat up a cylinder chamber, to reach compressed airs higher temperatures.

Direct injection moving also into petrol engine as well, but there is so many problems, like a lubrication the whole engine and others, thus this is not so popular. (new lexues, bmws use this direct injection in petrols). In these application is difficult to put in LPG, also lubrication of high pressure fuel pump is also difficult.
 
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