Best way to leave car idle for long-ish period of time?

[removed]

I'll have to leave my car (A160 W168) for just over 10 weeks, and while I can arrange for someone to run the engine for 10min while stationary, say once or twice a week, no one will be driving it. Now the question is: what would be the best way to deal with the situation:

1. Have the engine run for 10-15min every week for 10 weeks, or
2. Disconnect the battery

The battery was replaced about a month ago, with a brand new Bosch S5.

Car will be parked in a monitored multi-storey car park, so am a bit reluctant to disconnect the battery, as I'm not sure whether alarm will be off (and I suspect it will)?

 

[Deleted member 65149]

A difficult one. I think you're right that disconnecting the battery will prevent the alarm working. And even though you have a new battery, the security system would flatten it over a 10-week period if left unattended. My initial recommendation would be to get someone (trustworthy!) to start the car and sit in there with it running for 10-15 minutes about once a week.

However, I had a previous Merc broken into when parked in a monitored multi-story carpark and nobody took any notice (the only thing taken was the radio/CD ripped out of the dash). So something similar could happen to yours. Might be better to disconnect the battery so it keeps its charge and not rely on anyone else to visit regularly. But if it did get broken into, I wonder if your insurance company would say that the theft cover was invalidated by you disconnecting the power supply for the alarm system.

So in that case, I'd return to the starting up every few days option. That keeps the battery charged and provides an opportunity for someone to keep a regular check on your car.

 

[DSM10000]

Alarm systems have thier own battery.

I would also be inclined to not apply the parking brake in case it seizzes on but that may cause you other problems unless you can park it on a level area and possibly chock the wheels?

 

[bedwards1966]

Leave off the handbrake, it's fine in either bottom gear or park.
I would disconnect the battery, I'd expect it to go flat otherwise. Make sure you have (or can get) any radio codes needed afterwards.
I wouldn't bother starting it every now and then, 10 weeks isn't exactly a long time.

 

[removed]

Thanks knighterrant, DSM10000 and bedwards1966.

It'll be parked on a level area, so no problem leaving the handbrake off. I'll just leave it in park.

Still not sure about disconnecting the main battery, is there any way to check if alarm system own battery (if present that is) is okay and will survive 10 weeks?

The head unit is a double-DIN DVD I put in myself, so no worries about radio codes etc.

What about fuel - full tank or empty tank? Obviously, if going for a weekly engine start, I'll leave full tank, but what about disconnect the battery option?

 

[DSM10000]

All alarms require a separate battery independent from the main car battery to achieve the Thatcham insurance rating, these are usually sealed for life, do not recharge from the car and last for around 10 years so there is no issue with it draining.

As for fuel, it really does not matter.If you wish the engine to be run then clearly the battery needs to be left connected, if it is being 2 or 3 times for 15 minutes or so then it should keep the battery charge up.

 

[w124nut]

In addition to the advice above, I would inflate the tyres to 5-10 psi above normal to reduce the possibility of flat spotting.

 

[DSM10000]

+1

 

[jaymanek]

10 weeks is not a long time... cars sit in dealerships and used car yards for months and months at a time!

Wouldnt worry too much about the alarm, it will only annoy the neighbours when it goes off, doesnt really provide any protection. The immobiliser, which is part of the key is the security.
I would ensure firstly that your manual locks work, if there is no battery your remote locks wont work.

- Grease up the locks with spray grease - pref special lock grease
- Disconnect the battery
- leave in park
- ensure all doors are locked including boot
- do not leave anything half valuable in sight
- enjoy wherever you are going

 

[removed]

In addition to the advice above, I would inflate the tyres to 5-10 psi above normal to reduce the possibility of flat spotting.

Thanks, was thinking about it too, even though I put on all four new Michelin tyres only 7 weeks ago and done about 1,700 miles so far...

 

[The _Don]

Drop off at mine with full tank wife will use daily to ensure it is all tip top collect upon your return

 

[removed]

Drop off at mine with full tank wife will use daily to ensure it is all tip top collect upon your return

LOL ... tempting, but seeing as I won't even let my wife drive it, not the most logical solution

 

[martyz]

Just park it up as normal,10 weeks is nothing(it's not cold weather) on your return just jump in and drive off,if you are worried your battery might be flat put a jump pack in your boot.