It's not a jimny so I need help.

If you fit a C-Tek on permanent charge the battery will be charged as and when you need it. You will not need to drive it to charge the battery, the charger does it for you. as I said earlier, outflank the bugger.

Roger

And as I have said before, I am a realist, I don't batter my head against a wall, I look for a door. Fit the C-Tek permanently to the car with a simple extension lead to a suitable power point and put a note on the steering wheel telling the driver to disconnect it.

Roger

Lambert wrote:

What is wrong with wanting my car to be right? Why should I have to have my vehicle devalued, because I can't currently sell it in good faith knowing it has a fault?
 

But does it have a fault?

It has a draw on the battery which is within the manufacturers specification when not in use, it has been designed to be used in a certain way as agreed with the manufacturers algorithm. you are (potentially) wanting to use it outside of that algorithm, is that a fault?

Is there an option to fit a larger battery, is there a winter option for twin batteries, I thought some LC had them, our Surf did, but it was an import. 

With regards to the charger I get the impression that you think that it will be a hassle, having to open the bonnet, connect the leads etc. I'm not sure that is what is being suggested if it is then I am with you, but what I would expect to be provided is a discrete plug/socket in the grille, under the bumper etc. that you would simply connect the lead. As you are towing I presume you have an electric socket, depending on how it's been wired you could potentially introduce 12V at that point which would go all the way back to the battery.

I suspect that if you used the car on more regular basis then there would be no issue, which means you could should you wish sell the car with a clear conscience, however I would also suggest that whatever you replace it with is likely to have the same issue.

Every month I put the Audi on charge and it takes an hour to charge the battery. I then charge the Jimny and that takes 1.5 hours. In 10 years the Audi has done 33,000 miles. The Jimny has done 14,000 miles in 4 years. I changed the Audi battery 2 years ago - same size - and the Jimnies after 3 years - uprated. We don't have a problem with either. I don't consider that charging the batteries every month means that I have admitted that there is something wrong and I can't solve it. There may be a problem with modern day systems that to requires the electronics to act in a strange way to eek out every drop of fuel and I accept that because I cannot change it. I fight that which I can change and accept that which I can't.
Yes, my LC had a winter kit that included twin batteries and a heater built into the fuel filter and as long as I changed the batteries every 10 years the system never faulted. Didn't even have to charge them!

Roger

Lambert wrote:

What is wrong with wanting my car to be right? Why should I have to have my vehicle devalued, because I can't currently sell it in good faith knowing it has a fault?

Next question. If the battery is rated as 75Ah and I placed a draw on it of 1 amp it will maintain that for 75 hours?

In theory yes, but in practice no.  As the battery discharges the voltage drops and the load which took 1A now takes slightly less. Plus as a battery looses charge the internal resistance increases, this does a number of things:

it reduces the peak current, hence difficulty in starting; and
the terminal voltage drops further under load than the no load voltage, thereby reducing the current flow even more.

Then don’t forget that a battery is less able to give up its charge (or charge up) when it is cold.  Terminal voltage drops and internal resistance increases with cold temperatures to both limit the amount of power you can get out of your battery.

Robin

 

 About 18 years ago I had a similar problem with battery drain due to not using the car for long periods but in my case the battery was flat within a couple of weeks.  Under warranty the dealer replaced the battery a couple of times and did  electrical drain tests etc but never found the cause.  They eventually told me the car was designed to be used not sit in a garage. I gave up trying to sort the problem and kept the battery on charge while it was not in use for the 10 years I had the car.  Because my Defender has little use I use a Ctek charger which I like others would recommend in your situation. As someone has already mentioned Ctek  make a plug which goes into the towbar socket providing it is of the correct type or you could use the cigar lighter if you have one.
​​​​​​One thing the dealer didn't do was change the alternator because the output was within tolerance.  I have since learnt that alternators have a diode which if faulty will cause battery drain even when the vehicle is turned off and the alternator is not operating.