Battery drain?

[ryszard]

Hi,ref connecting neutral to a body earth is probably recommended for some newer cars which have a battery monitoring system.My Jaguar has a battery monitor and the reason for connecting to a separate earth is to let the monitor know the state of battery.If the negative is connected directly to the battery it by passes the monitor,and although the battery is fully charged the monitor will not register this immediately and will still show the battery low,start engine warning signs.It will also shut down non essential items such as radio to conserve power.Regards Ry....

[SD1too]

Originally Posted by ryszard

If the negative is connected directly to the battery it by passes the monitor ...

How does that work then Ry?

Simon

[COLVERT]

Originally Posted by SD1too

How does that work then Ry?

Simon

Me too, me too.--If there is something new to learn I want to know how it works.----


Oh !!! And why it's needed.----

[COLVERT]

Connecting battery chargers to the battery.--I never use the battery earth pillar.--Somewhere away from the battery, maybe on the engine.

Why take the risk of a battery explosion and getting yourself covered in acid when it just isn't necessary.

Just the way I work. Safety first, always.

[ryszard]

Originally Posted by SD1too

How does that work then Ry?

Simon

Hi,I've no idea,I have an X351 Portfolio,it is a known recommendation on the Jaguar forum,seems it is from the 2010/2011 model.All I know there is some gadget in the lead after the battery connection.The battery monitor is a nuisance,it seems if your working on the car with ignition off and maybe a door open or boot after a short while the warning message appears,low battery,start engine.It will shut down non essential power draining components to keep the essentials active.After two years I still find it irritating and worrying,have been told mostly to ignore it,but I always keep a smart charger on it if not used for several days.There are several theories probably to do with the electronics,keyless entry,sensors active all the time?
Mine is a 2011 Claret diesel Portfolio,bucket list car,it is a comfortable powerful and imposing car,but I prefer my 75 diesel SE,90% of the time it's the Rover I take,the Jaguar is like most modern cars too refined and dare I say it too emotionless.Im old fashioned and like excitement!.Regards Ryszard...

[Charles]

Originally Posted by COLVERT

Connecting battery chargers to the battery.--I never use the battery earth pillar.--Somewhere away from the battery, maybe on the engine.

Why take the risk of a battery explosion and getting yourself covered in acid when it just isn't necessary.

Just the way I work. Safety first, always.

I can't argue with the last sentence. I was always taught to disconnect the battery before charging, however, so connecting the charger to both battery posts is the only option. The new trickle-charger is supposed to be safe to use without disconnecting the battery, however, so connecting the neutral lead to the bodywork is an option; where would you suggest?

[SD1too]

Perhaps I can offer a few words which hopefully will reassure.

Originally Posted by Charles

I was always taught to disconnect the battery before charging ...

In my younger days I used to follow this rule too until I stopped to think: why am I doing this? What is the difference between the charger's crocodile clips correctly connected and the cable from the alternator. The answer, of course, is absolutely none. Furthermore, there is no possibility that any current can flow from the charger back into the alternator because it would first encounter the alternator's diodes which will block it. Electricity always takes the easiest route and that is through the battery and back to the charger.

So despite what some might tell you, it is not necessary to disconnect the battery before charging.

Originally Posted by Charles

... so connecting the neutral lead to the bodywork is an option; where would you suggest?

To the point at which the black battery negative cable is attached to the bodywork.

Simon

[Charles]

Originally Posted by SD1too

Perhaps I can offer a few words which hopefully will reassure.

In my younger days I used to follow this rule too until I stopped to think: why am I doing this? What is the difference between the charger's crocodile clips correctly connected and the cable from the alternator. The answer, of course, is absolutely none. Furthermore, there is no possibility that any current can flow from the charger back into the alternator because it would first encounter the alternator's diodes which will block it. Electricity always takes the easiest route and that is through the battery and back to the charger.

So despite what some might tell you, it is not necessary to disconnect the battery before charging.

To the point at which the black battery negative cable is attached to the bodywork.

Simon

The same question has often occurred to me, but I'm not enough of an expert to feel confident about it.

One thing I like about this is that it has often occurred to me that reconnecting the battery after charging seems to be the most dangerous part of the operation. Provided the charger is switched off, there is no risk of a spark when connecting or disconnecting the crocodile clips, but there is sometimes a spark when reconnecting the battery. I try to prevent this by making sure all the electrical equipment is switched off before charging, but leaving the battery connected would eliminate the risk of a spark altogether.

One other question: is it safe to close the bonnet while charging, or does this risk a build-up of gases inside the engine bay?

[SD1too]

Originally Posted by Charles

... there is sometimes a spark when reconnecting the battery ... leaving the battery connected would eliminate the risk of a spark altogether.

You're absolutely right Charles. I'd say that the myth has been exposed!

Originally Posted by Charles

One other question: is it safe to close the bonnet while charging, or does this risk a build-up of gases inside the engine bay?

Well, the bonnet is closed whilst you're driving around and your alternator is charging the battery so there you have your answer.

Simon

[COLVERT]

Originally Posted by Charles

The same question has often occurred to me, but I'm not enough of an expert to feel confident about it.

One thing I like about this is that it has often occurred to me that reconnecting the battery after charging seems to be the most dangerous part of the operation. Provided the charger is switched off, there is no risk of a spark when connecting or disconnecting the crocodile clips, but there is sometimes a spark when reconnecting the battery. I try to prevent this by making sure all the electrical equipment is switched off before charging, but leaving the battery connected would eliminate the risk of a spark altogether.

One other question: is it safe to close the bonnet while charging, or does this risk a build-up of gases inside the engine bay?

Not much gas given off and only dangerous if you are very close to the battery.--( ie. the battery terminals. )

The way you suggest is the best way to avoid any possible electrical spikes.