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[x25xe]

Hi all,

I subscribe to Car Mechanics and find it to be an excellent read.

This month they featured an article about battery chargers.  They recommend the CTEK 36 charger and state that this can be used with the battery still connected to the car.

As I have two cars, I would like to use the charger in this manner to keep the battery topped up in the car that is standing.  I always thought that the battery had to be disconnected before charging to save damage to the alternator diodes.  So, my questions are:

1.    Can this unit be safely used with the battery connected to the car?
2.    Has anyone got one of these chargers and are they as good as is claimed?

Thanks for any feedback

[JamesV6CDX]

must be honest, I don't like the idea of charging the battery while it's still on the car....

[Cornish Crow]

hi people, we charge all our batteries at the garage whilst they are on the vehicle, but if the battery has a green light indicator on the top, we have to use a special type of trickle charger or it damages the cells or something like that, i would say check what battery you got then decide.
from the crow

[Taxi_Driver]

must be honest, I don't like the idea of charging the battery while it's still on the car....

Must agree i dont charge my battery if its fitted to the car.....but depends on the charger....1/2 amp trickle charger is prob ok on the car tho i still take mine off if needed and then still charge it at 1/2 amp trickle charge.....dont like charging it at 4/5 amps.....but it prob gets at lot more abuse from the alternator when fitted on the car  :-/

[Markjay]

Hi all,

I subscribe to Car Mechanics and find it to be an excellent read....

Indeed - as some of you may know I am a regular reader and it is a great magazine. Highly recommended!

[JamesV6CDX]

Think about it, for the time it takes to get a 13mm and whip off one of the terminals, what's the point in risking loom damage?

[Marks DTM Calib]

10mm spanner for the terminals.....13mmm for the bracket......

Battery chargers are generally crude items....(switches in to Electronic/electrical Eng mode....)

Often they are little more than a transformer, rectifier and thermal trip......in this style they are not good for car electronics....and I am yet to find a cheap charger with any form of smooting or current control inside!

The rectified supply needs to be greater than 14-15V in order to put charge into the battery for the full period of charging......as a result, the un-smoothed supply peeks at 20V+.....and in order to charge at a higher current....the charger simply ups the supply!

As for sealed batteries.....these have a vent which releases excess pressure from the build up of gases inside.....if you charge them at a high charge rate they get warm, the gases build up and vent off.....your battery will now have less fluid in it meaning you have just shortened its life....

[TheBoy]

10mm spanner for the terminals.....13mmm for the bracket......

Battery chargers are generally crude items....(switches in to Electronic/electrical Eng mode....)

Often they are little more than a transformer, rectifier and thermal trip......in this style they are not good for car electronics....and I am yet to find a cheap charger with any form of smooting or current control inside!

The rectified supply needs to be greater than 14-15V in order to put charge into the battery for the full period of charging......as a result, the un-smoothed supply peeks at 20V+.....and in order to charge at a higher current....the charger simply ups the supply!

As for sealed batteries.....these have a vent which releases excess pressure from the build up of gases inside.....if you charge them at a high charge rate they get warm, the gases build up and vent off.....your battery will now have less fluid in it meaning you have just shortened its life....

Agree, most are quite crap.  Still, they are an improvement on the old plate rectifier type...

[Markjay]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

[TheBoy]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Shortish journeys, esp in winter....

[Ghosts in my machine]

I've got a Draper Battery Master to keep the battery on my Landy topped up. only cost about £15. Keeps the battery fully charged and the alarm going. You don't have to disconnect the terminals on this unit according to the instructions and I never have.

It's been running for 7 years on and off and never had a problem.

[TheBoy]

I've got a Draper Battery Master to keep the battery on my Landy topped up. only cost about £15. Keeps the battery fully charged and the alarm going. You don't have to disconnect the terminals on this unit according to the instructions and I never have.

It's been running for 7 years on and off and never had a problem.

TBH, 9 times out of 10 you will get away with it on trickle chargers.  Fast charging can screw up the diode pack and regulators...

[Marks DTM Calib]

..........and its not like there is anything to complex on a Land Rover!

[TheBoy]

..........and its not like there is anything to complex on a Land Rover!

Hey, leave LR alone - they do the job they were built for, and do it better than anything else

[TheBoy]

..........and its not like there is anything to complex on a Land Rover!

Hey, leave LR alone - they do the job they were built for, and do it better than anything else

Except maybe Massey Tractors

[Markjay]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Shortish journeys, esp in winter....

In my experience - with a good battery, properly charging alternator, and no current-drawing faulty devices, you will not need a battery charger even with short winter journeys... I suspect that most cases where a trickle charger is needed it is actually covering-up a problem - usually an ageing battery.

[TheBoy]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Shortish journeys, esp in winter....

In my experience - with a good battery, properly charging alternator, and no current-drawing faulty devices, you will not need a battery charger even with short winter journeys... I suspect that most cases where a trickle charger is needed it is actually covering-up a problem - usually an ageing battery.

The old addage that you need a 20min run to put back in a 5s start?  Couple that with HRW on, possibly seat heaters, wipers, lights etc etc...

[Markjay]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Shortish journeys, esp in winter....

In my experience - with a good battery, properly charging alternator, and no current-drawing faulty devices, you will not need a battery charger even with short winter journeys... I suspect that most cases where a trickle charger is needed it is actually covering-up a problem - usually an ageing battery.

The old addage that you need a 20min run to put back in a 5s start?  Couple that with HRW on, possibly seat heaters, wipers, lights etc etc...

OK, I suppsoe that if you take into account LB's sound system (or so I heard) then yes, you could flatten the battery in one short journey...  

[TheBoy]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Shortish journeys, esp in winter....

In my experience - with a good battery, properly charging alternator, and no current-drawing faulty devices, you will not need a battery charger even with short winter journeys... I suspect that most cases where a trickle charger is needed it is actually covering-up a problem - usually an ageing battery.

The old addage that you need a 20min run to put back in a 5s start?  Couple that with HRW on, possibly seat heaters, wipers, lights etc etc...

OK, I suppsoe that if you take into account LB's sound system (or so I heard) then yes, you could flatten the battery in one short journey...  

A weeks worth of short winter journeys will make a significant dent in the battery capacity...

[x25xe]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

Fully agree with your list of why the battery is going flat.  However, I am looking for a charger as the car is left standing for anything up to 2 months.  With the alarm and immobiliser on all the time, the battery is somewhat drained.  I was hoping to be able to connect a trickle charger to avoid this.  According to the web site of the manufacturer, this is safe to do, but there are doubts in the back of my mind to be honest.

http://www.ctek.com/EN/MXS3600/features_benefits.asp

Apparently, there is virtually zero ripple and the output is finely controlled.  It is based on a switch mode PSU rather than a transformer and bridge rectifier etc.

[Markjay]

Fully agree with your list of why the battery is going flat.  However, I am looking for a charger as the car is left standing for anything up to 2 months.  With the alarm and immobiliser on all the time, the battery is somewhat drained.  I was hoping to be able to connect a trickle charger to avoid this.  According to the web site of the manufacturer, this is safe to do, but there are doubts in the back of my mind to be honest.

http://www.ctek.com/EN/MXS3600/features_benefits.asp

Apparently, there is virtually zero ripple and the output is finely controlled.  It is based on a switch mode PSU rather than a transformer and bridge rectifier etc.

This is what I have on the wife's MPV:



http://www.demontweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=LMA789C

Admitadly, it will also cut-off any alarm you have (the MPV has none), you will need to re-code the radio (the MPV does not have a code on the radio), and the engine and gear ECU will forget everything (the MPV does not learn anything in the first place). So maybe not such a bright idea to use on the 'meega  

 

[TheBoy]

The PSU type won't make huge amounts of difference, though admittedly the smps will be at much higher frequency so arguably easier to smooth.  But a well designed linear psu will be every bit as good (though probably heavier!)

[Taxi_Driver]

I only have a battery charger for just in case.....i have taxi kit fitted and it does drain the battery a bit....sometimes i forget to switch it off in the evening so its on all night...its powering a colour lcd screen....and a tx that i think transmits at about 4w.....and is always tx'ing......ok not much power but if the battery was low....and i do about 20-30 starts a day also hammering the battery.....sometimes turn off during these gloomy days and forget to turn off headlights....plus i use the auto button quite a bit at the mo when turned off.....also draining the battery.....so as i said MJ its only for just in case....as i dont like jump starting if a flat battery.....once fubared a veccy ecu by doing that!

[Auto Addict]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

[Taxi_Driver]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

Now you mention that AA......so do I  

[Markjay]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

Now you mention that AA......so do I  

 

[Del Boy]

must be honest, I don't like the idea of charging the battery while it's still on the car....

Am agreeing here

[Markjay]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

Now you mention that AA......so do I  

 

AA and TD, I’ll have you know that

1. This was an isolated incident

2. It happened next to my office, so even if I had a battery charger (at home) it would not have helped

3. I called Green Flag, but managed to get the car going before they arrived

4. Even if it did happen at home, I wouldn’t have been able to use a battery charger because I park in the street and don’t have a garage!  

So there….

[Auto Addict]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

Now you mention that AA......so do I  

 

AA and TD, I’ll have you know that

1. This was an isolated incident

2. It happened next to my office, so even if I had a battery charger (at home) it would not have helped

3. I called Green Flag, but managed to get the car going before they arrived

4. Even if it did happen at home, I wouldn’t have been able to use a battery charger because I park in the street and don’t have a garage!  

So there….

Excuses, excuses, excuses....

[Taxi_Driver]

I don't entirely understand why would you need a charger in the first place... unless the car is in storage for a long period of time, any need for charging suggests that there is a problem:

1. Something is drawing too much current with the ignition switched off
2. The battery is in need of replacing
3. The alternator does not charge properly due to a fault (damaged coil, faulty voltage regulator, etc)
4. The alternator does not charge properly due to auxilary belt problems (failed tensioner, slipage due to oil leak or glazing, etc)
etc, etc...

If this is the case, why not simply find and cure the source of the problem? If the battery needs replacing, for £30+ and a five minutes job, just get it done... it will be good for another 5 years or so. Why trickle charge a faulty battery?

As for storage, I found that I have no problems at all when the car is parked for up to 2-3 weeks (when on holiday etc). On my other car, I simply disconnect the battery - it's a very basic car with no alarm or radio code etc so the battery can just be connected and disconnected. In fact I even have a proper battery cut-off switch installed between the negative terminal and the car body, so no need for a spanner. You will be surprised how long can a car battery keep it's charge when it is disconnected - months is no problem.

And, in the unlikely event that the battery does go flat (e.g. when TB updated the firmware... lol), a quick jump-start and then a short blast on the motorway seem to cure the problem.

So, again, why do you guys need battery chargers in the first place?  

I seem to remember a certain somebody (who shall be nameless, of course) sat with his headlights on when he was speaking on his mobile.....and ended up with a flat battery....

Now you mention that AA......so do I  

 

AA and TD, I’ll have you know that

1. This was an isolated incident

2. It happened next to my office, so even if I had a battery charger (at home) it would not have helped

3. I called Green Flag, but managed to get the car going before they arrived

4. Even if it did happen at home, I wouldn’t have been able to use a battery charger because I park in the street and don’t have a garage!  

So there….

Excuses, excuses, excuses....

Im sure tho MJ, if you did have one you would carry it in the boot with everything else.....and im sure you have the correct tools to remove the battery and carry it inside to charge  

[Ghosts in my machine]

Have a look at:

http://www.draper.co.uk/Pages/Pagesource/p67.pdf    item 4.

This is what I was on about. Works for me and is a lot cheaper than the CTek unit (and about half the price).

You could always use it just for the radio memory etc. and disconnect the battery (Sticking it on trickle charge every now and again).

Always liked battery isolation switches with a big red key (especially the ones with removeable keys). Best immobiliser you can get, as I don't think that thieving scum even think to look for one, or know what it does!

Back to the much maligned (on this site) Landrover, its got the Isolation switch under the seat, sometimes its stopped me starting it . . . . when I've forgot that I had it fitted! [smiley=grin.gif]

[Auto Addict]

Have a look at:

http://www.draper.co.uk/Pages/Pagesource/p67.pdf    item 4.

This is what I was on about. Works for me and is a lot cheaper than the CTek unit (and about half the price).

You could always use it just for the radio memory etc. and disconnect the battery (Sticking it on trickle charge every now and again).

Always liked battery isolation switches with a big red key (especially the ones with removeable keys). Best immobiliser you can get, as I don't think that thieving scum even think to look for one, or know what it does!

Back to the much maligned (on this site) Landrover, its got the Isolation switch under the seat, sometimes its stopped me starting it . . . . when I've forgot that I had it fitted! [smiley=grin.gif]

This is the one I've got.

http://www.machinemart.co.uk/product.asp?p=010310012

[TheBoy]

Back to the much maligned (on this site) Landrover

Not by me. LR is the only proper 4 x 4

[Auto Addict]

Back to the much maligned (on this site) Landrover

Not by me. LR is the only proper 4 x 4

Well said that man

[hotel21]

Back to the much maligned (on this site) Landrover

Not by me. LR is the only proper 4 x 4

Well said that man

Not me either.....  Had a load of fun in Landies...