11 replies to this topic

[pdaykin]

I'm sure this has been covered before but I can't find it.

 

But how long should the battery last on a car that is stood ?

 

[nicklouse]

it depends.

 

why are you asking?

 

is it flat? was it still connected? did you check for any parasitic drain?

[Ethel]

Flat batteries suffer a premature death.

[pdaykin]

It is a new battery. New alternator - changed as the bearing died. Seems to be charging fine. If the battery is left in the garage after charging it can be put in the car weeks afterwards and away it goes - so no problem holding charge.

 

The car gets used very little. When I do come to use it, the battery is invariably dead.

 

Clearly, something is drawing power. Just curious as to what is considered a normal length of time for a stood car to drain the battery.

 

Due to a software issue, our "modern" did flatten the battery after a few days as there are lots of hidden drains on the battery.

 

Not sure there are quite that many in a mini. Always assumed it would basically be the clock and alarm.

 

So I'd have thought at least a month stood idle should be OK ? Or am I wrong.

[mini13]

mmm,

 

you should only see  about 200mA max current draw with nothing on (ie alarm and any ofline electronics), although the old smiths clocks can pull more than this I think. at that 200mA draw your probably looking at 2-3 weeks on an average battery before it becomes an issue.

 

one think that will kill batterys is a discharge, even on a new batery a discharge will reduce it capacity a lot.

 

can you stick a solar panel int he car to offset the drain of alarm etc.

[pdaykin]

It is probably about 3 weeks I'm getting out of it so maybe it isn't too far off the mark

[nicklouse]

Measured the parasitic drain?

And do you need to have it connected?

[pdaykin]

Not measured it yet. If I get an hour free I will do.

I always leave it connected to make sure the alarm is powered up.

Never have this problem with my mk1s - they have so few electrical bits I think a watch battery would power them

Edited by pdaykin, 21 April 2016 - 07:03 PM.

[Alpenflitzer]

Use a battery interuptor switch which has a by pass for the electronics.

[Shifty]

MPi's don't seem to last very long, mine can't do much more than a couple of weeks of no use before its flat.

[angelinasoul]

Mine daily used about 20 miles, last for 15 months.

[ukcooper]

mine last's 2weeks just standing there till the alarm led goes out from full charge ((charger) mpi).

wont start after a week.

Killed one battery off after 6 months of no use.