10 replies to this topic

[ianat43]

Hi

 

Is there a common fault with mpi's that can cause the batteries to fail as the ones on mini 40 do not last very long.(3months for the last)

Should point out the charge from the alternator is good the connections are good, battery acid level is good and car has only done 3300 miles .

Battery being used is a 038.

 

[phil hill]

I wouldn't say there is a common fault which particularly afflicts MPi's any more than other Mini's.  True enough the injection Mini's are less tolerant of low battery voltage as it causes the sensors to "tell lies" to the ECU, but that shouldn't be a problem once the alternator starts charging the battery back up again.  

 

Check the usual suspects: main battery earth in the boot, battery terminals on both positive and negative in the boot, engine to body earth strap in the engine bay.  Also on the injection models check the Brown coloured wires on the starter motor solenoid, they have a habit of getting green verdigris corrosion which can bridge out to the body of the starter, or cause the terminals to break up prematurely.  Also check the master fuses are clean and the voltage at these master fuses is as close to battery voltage as possible.  Sometimes the brown wires from the solenoid get micro-breaks in them which causes an increase in resistance, therefore loosing voltage and increasing demand on the battery and alternator.

 

Having said all of that, that would affect the car running rather than draining the battery.

 

The alarm and clock shouldn't draw a large quiescent current, nor should the radio, but you could check by disconnecting them and seeing if the battery holds up a while longer.

 

Finally if the battery has gone "dead flat" repeatedly then it's overall capacity will have diminished greatly and so it may be time to replace it.  Personally I would say the 038 battery is on the small side for an MPi.  There is a sticky thread on batterys in the main section here, many people recommend the battery from a Peugeot 306 diesel.  I have one from an Astra/Nova Diesel which was installed in 2000, is only used for 6 months of the year if that, and is still going strong (there that's buggered it now !!)

 

Phil. 

[phil hill]

Another thought, if you don't use the car often try using a battery maintainer/charger like an Oxford, Optimate or such, or if the car is left outside use one of the solar chargers from the likes of Maplin.  They come on "special offer" every once in a while, I have one which is about the size of an A4 sheet and it keeps the battery topped up when not in use.

 

Phil.

[ianat43]

Thanks Phil

 

I will check it over again in the morning.

You mention using the 306 diesel battery in the mpi's. Could you tell the model number for the battery?

Thanks Ian

[phil hill]

Hi Ian.

The ones recommended seem to be either 063, 075 or about the biggest which will fit is 096 but the last one is apparently a very tight fit. I would recommend getting to an independent motor factor or somewhere like Euro car parts rather than the place with the orange and black logo........... simply because of price. Varta and Bosch have excellent reputations for batteries but are a bit more money. Buy cheap buy twice as they say.

Have a look in the F.A.Q. section under electrical, there are a few post there about Injection Minis and batteries etc. Most of the posts are written by KernowCooper and he really knows his stuff. I just read the post about fuseable links as I'd forgotten about them and actually thought those brown wires on the solenoid were just wires. Anyway you can read them yourself, and the guide for checking batteries, alternators etc, how to check cables and grounds etc.

If you want a hand you could always take a ride down to Lincoln and I'll have a look with you.

Phil.
Edited because of phone typing darn it!

Edited by phil hill, 30 August 2015 - 10:00 PM.

[DFulton]

I have an MPi that only gets driven at weekends / infrequently.  On a brand new battery, it can usually survive being parked up 10 days before going flat.  No significant drain and alternator working fine, so I'd say your low mileage is the main problem.

 

Another thought, if you don't use the car often try using a battery maintainer/charger like an Oxford, Optimate or such, or if the car is left outside use one of the solar chargers from the likes of Maplin.  They come on "special offer" every once in a while, I have one which is about the size of an A4 sheet and it keeps the battery topped up when not in use.

 

Phil.

 

 

I've not tried the solar ones suggested above, so can't vouch for them, but I now hook up a Halfords maintainer / charger when it's going to be more than 48 hours before I take the car out again.  I've found this eliminates the problem.  I also have an old, not completely ruined, battery in the garage, that I charge up when the charger isn't connected to the car.  If I need a quick jump start, this is far easier than bringing another car into play.

[KernowCooper]

Hi Ian, just carrying on from Phils advice above, the biggest battery from all brands that will drop in is the 075 as mentioned, I have one in mine and is the 306 Diesel Battery, some have gone one bigger to the 096, and depending on make the 096 needs the retaining lips trimmed off, 075 will do everything you want and is drop in.

[FlyingScot]

Check the current drain in the battery when it's off.
The multi function unit (black relay box) stays on for a time delay on the MPi and sticking contacts can cause it to drain the battery.
Likewise a failed driver circuit in the ECU can cause the MFU to stay energised.
If you check the current drain then you will know if something is powered up and killing off your battery.

FS

Edited by FlyingScot, 31 August 2015 - 05:12 AM.

[Steve220]

The alarm has a terrible parasitic drain on the battery on the MPi. I just disconnect the battery now and keep it on a trickle charge as I'm fed up with trying to jump it every time I want to use it.

[ianat43]

Thanks to all the replies.

I'll be getting a 075 battery in the week and carrying out some tests when and if it stops raining.

[ianat43]

• Ok fitted a 027 battery yesterday and got to work and back without having to get jump started .Still manage to get the spare in the boot but only just. Cardboard battery cover left in garage
• Tried again to charge the original battery with charger and no good so looks like battery is just had it . Guess I just got a bad one. Fitted a bosch S4 005 model which was the spare for the wife's scenic and hopefully better quality.
• I shall wait and see and keep it topped up over the winter.
• Thanks all for your help.
• Ian