Earth Leakage Fault

[Guest Aqua]

Does any one know what the normal battery drainage current whilst stopped for an 02 Galaxy 2.3 Ghia is?

 

I am having a bit of a struggle with our local Dealer to get them to idenditfy and rectify electrical fault / faults which drain the battery such that the vehicle cannot be started if left standing for more that 3 days.

Weve had a new 70Ahr battery fitted and an apparently faulty heating valve, and faulty fuse box renewed. The cars been with the experts 54 days this last 3 months and still not fixed!!

 

I have suggested that in order to determine if the fault has been rectified one needs to check the discharge rate with car locked up. As far as I can determine I think the discharge rate should be less than 75 milliAmps - Am I correct ?

 

Also anyone any ideas for hidden faults beyond the obvious? It is quite possible that it could be intermittant therefore making it harder to find.

[chromedome]

I've got a 2001 Ghia Auto, all the usual mod cons. I know this doesn't help but I've just left mine standing for three weeks and everything was fine, started first turn.

 

There's been a bit of talk on the forum recently about flat batteries. Might be worth a search.

[seatkid]

Mine is around 50mA.

[Masked Marauder]

The only way you can find what is causing a drain is by connecting an Amp meter between the battery and the lead and pulling the fuses/relays one at a time until you find the leak. Then you have to investigate where in that circuit the leak is.

[Sharanfx]

Common causes are stereos. alarms, phone kits and Sticking relays.

 

Like said the best way is to connect up an ammeter and pull fuse untill you find out what is draining it.

 

I would say 0.75A is a little high and you would expect no more than 0.5Amps. with the car locked up.

[Ivor_E_Tower]

He did say 75 mA, not 750 mA - 0.75A is definitely too high !

 

You could try a current probe rather than having to disconnect each major wire in turn and wiring in an ammeter. It may cost a few quid to buy one, but still cheaper than one hour's lanour at a Ford garage. Try Maplins or RS websites/shops.

[Guest Aqua]

Saga still continues - car is still spending more time with dealer than on our drive.

Its just been picked up again for another look into the persistant problem.

The vehicle can only be left standing a max of 5 days before there is insufficient power left in the battery to alow it to start.

I measured the discharge ratethe other day at 0.022A. So looks like either its an inermittant drain or the battery is goosed or a combination of both.

 

Just for info purposes for you other folks I have gleened the folowing from yourselves and other sites -

(I have had to look into this in order to counter the "Bull" from the local dealer wich included quoting the battery fitted as being 680Ahr so would be man enought for a 0.2Amp parasitic drain and the battery voltage having been measured at 14.7 V after charging with a reading of 14.5V a week later with no use !!!)

 

Battery Rating -

Batteries capacity is normally quantified by an Ampere hour rating.

The definition of which is the current the battery can supply continuously for 20 hours without the voltage falling below 10.5 volts.

 

Cold Cranking Rating (EN) -

Cold Cranking Rating is the discharge current given by the manufacturer. It is the current emitted by the battery at a temperature of -18'C whilst maintaining a minimum voltage of 7.5 Volts for a period of 10 seconds.

 

 

Battery Charge -

Standard 12 V Car Batteries are made up of 6 cells, with 2.1V per cell. So its fully charged at 12.6V across the terminals.

At 12.6 Volts the battery is 100% fully charged

At 12.4 Volts the battery is 75% charged.

At 12.2 Volts the battery is 50% charged.

At 12.0 Volts the battery is 25% charged.

 

Generally, however, at 12.4 volts or more the battery is considered to be charged. At 12.39 Volts or less the battery is considered to be discharged.

 

 

Barrier Layer Sulphation -

This phenomena occurs when batteries are "deep discharged". Sulphur molecules come out of the acid and form on the plates. This reduces the batteries capacity. In severe cases with silver-calcuim cells the reduction of capacity can be as much as 40% on the 1st occasion.

 

"Marine Batteries" (Deep Cycle Batteries) have thicker plates and are designed for a long slow discharge rate. These do not suffer from sulphur build up nearly as bad. They are more expensive, but are not damaged by full discharge.

 

 

Battery Charging -

Optimal charging voltage of a cars regulator is 14.2 Volts. If a regulator is set too high the water will be electrolysed. This lowers the electrolyte over time and consequently damages the battery. If a regulator is set too low, the battery will not be charged properly, this also shortening its life span.

[morphico]

Hi,

 

I had a similar problem on my galaxy. Found it to be the stereo amp in the end.

 

One of the amps had overheated and shorted allowing current to drain to earth at a trickle. It had killed one of the rear channels but i wasn't that worried about it.

 

Never noticed it till i left the car a week, came to use it and it was dead.

 

Don't know which type of stereo you have, mine has the 2007R with the remote amp, ended up disconnecting the rear amp's and connecting all outputs off the front to common with the rears till i could get another amp off ebay.

[Guest Aqua]

Hi. We have the 6000CD unit fitted with a 6 disc autochanger mounted in the back.

The Dealer blew the autochanger last time it was in - I am hoping that this should be renewed this time.

 

I have just heard from the dealer that they have found some loose nuts behind the fuse box causing a large drain. May or may not be the problem. They changed the fuse box last August, amongst other things, so unless the nuts were loose before they started and never tightened them afterwards then maybe not - time will tell.

;)

[seatkid]

To test if your battery is goosed, try disconnecting it for five days and then see if will start....

 

I doubt that high drainage would be "intermittent", 22mA is perfectly normal.