Battery Life Expectancy

unesential · 3rd October 2007, 14:00

Since joining I have read numerous threads on Battery not holding charge. I was just wondering if our beasts are also rough on batteries. I ususally expect 5 years of service from new however, I find myself in need after 3 years. Is the norm due to cycling from limited use or is it the nature of the beast. I don't let her sit on a maintainer as I tend to use about 2-3 days per week.

JED · 3rd October 2007, 16:08

Sounds about right. Mines two years old, and showing signs already. I do keep it plugged into a battery conditioner now though to help it out.

If left on its own, it would discharge within three weeks.

farrell · 3rd October 2007, 16:33

3-5 yrs is normal dependant on usage.
My own experience echoes Jeds in that the car if left unused will flat the
battery almost completely in 2.5-3 wks.
That why I fitted a 105 Amp / 1400 mA battery to mine & a couple of other cars I have worked on.

You have a better charge balance ratio & the greater capacity gives you a
fighting chance of cranking first time after that 2 wk holiday.

Cheers
Farrell

legacy260 · 3rd October 2007, 17:24

I keep mine plugged into a trickle charger and it works beautifully. However before I did this within three weeks it would be flat. A replacement did little to improve the drain. Charge it or use it...

unesential · 3rd October 2007, 18:13

the 2-3week drain down I understand and figure this what has caused the shortened life of the cells. Now if I only knew where I put the receipt for the last 72 month battery so I could get something off the knew one.

Alan Archer · 3rd October 2007, 18:30

Have had one battery in 8 years,
probably around 3 years ago.
Went for a genuine BMW unit correctly rated too.

Dont use the car much during the week and sometimes its dormant
for a couple of weeks so it sits hooked up to an Oxford optimiser.

This ensures it never looses charge, essential with an alarm & 2 immobilisers!

What I would mention is I specifically avoided a fancy trickle charger
that cycles & does desulphation pulse charging and the like...
as I didnt fancy the cars electronics being subjected to voltage spikes
no matter how low the current...

Regards,

Alan.

farrell · 3rd October 2007, 18:42

Good point m8.
I run a couple of optimsers...even so I use them, then disconnect & reconnect
once a week.

Cheers
Faz

Mmm-Five · 4th October 2007, 07:52

I've had 4 replacements in my 3.8.

replaced original BMW battery when it wouldn't hold a charge.
2nd BMW melted and dropped its lifeblood in the battery compartment when the alternator overcharged it.
3rd battery (from RAC) did the same as 2 on the way home from being 'fixed' by the RAC
Bosch battery with similar specs fitted.

Teamsreth · 4th October 2007, 10:28

I need to look into an optimiser, any ideas/recomendations?

What with the Alarm and Immobiliser, and the tracker, 2 weeks of inactivity will require a helping hand.

unesential · 4th October 2007, 14:03

So the question is does the optimiser extend the life to what the manufacturer gives in warranty or just buy a cheap battery and figure on relacing every couple of years?