Battery info - Can you kill a battery so quickly?

[les5709]

Hi Guys,

As some of you might remember i have had issues with my noble charging the battery.

The car has been off the road for around 2 months, lying about with no charge going to the battery. It was a wiring issue, wires melted together round turbos and a few other areas. This has now been totally rewired and the battery light in the dash is now out

Now the car is charging around 14.6v, But... If i was to say start the car, or leave the ignition on for a short time, and run the CD player or even run the blowers (with the car started, idle but no revs) the car would stall and just power down and not start again without a bump start.

Is it possible that wiith 2 months of the battery not charging, that it could have damaged the battery to the extent that it doesnt hold enough charge, and hence why the odd time the car will stop on me if i dont get in it and rev it right away.

I dont know if this is related but the alarm is also now not making the bleep when u try to unlock, i was wondering was this also a sign of low battery??

Thanks
STeve

[Gadgeroonie]

sounds like you my have a leak to earth, causing the battery to discharge

how long do you leave the car before you start it ?

[les5709]

Gadgeroonie said:

sounds like you my have a leak to earth, causing the battery to discharge

how long do you leave the car before you start it ?

The other night i was sitting in it for around 20mins just with ignition turned... I turned all lights off, and turned cd player to off mode. I just left ignition on to stop the alarm going off as i was sitting in the car. It just clicked on attempting to start

Last night I drove the car say 20mins down to my sports training, left it for say 2 hours. After training I started it leaving it just ticking over for 5mins with the blower to clear the window as it was steamed up.

As i went to pull off it just died on me and waved the white flag. Had to bump it with a struggle.

Edited by les5709 on Friday 8th October 09:34

[Adrian W]

If you leave most car batteries flat for more than a few days it is unlikely that they will recover, you can buy deep discharge one's, but in reality they're not much better.
AS an aside I used to do a lot of water skiing, we seemed to buy more batteries than anything else.

[les5709]

Adrian W said:

If you leave most car batteries flat for more than a few days it is unlikely that they will recover, you can buy deep discharge one's, but in reality they're not much better.
AS an aside I used to do a lot of water skiing, we seemed to buy more batteries than anything else.

Yeah i mean normally I would be out driving the car or at least start it every day as i know the nobles use battery when they just sitting there doing nothing. I also forgot to say the battery is just new when i first had the charging issues, but with these issues it has been lying there since first week in august with no charge.

[AMG Merc]

It must be something with me and batteries but they last years - one Merc ran for 9.5 years on original (although a bloke in the shop said that was impossible!) and Noble still on original from 04 :-)

[Gadgeroonie]

sounds like you have a bad earth / live

i suggest you get an Auto Electrician to fix the problem

[jdearden]

I finally killed mine a few weeks back at it was on the original from 2002

[jdearden]

I finally killed mine a few weeks back at it was on the original from 2002

[joust]

Have you let the battery totally discharge (i.e. so it won't unlock the doors)?

If so, due to the battery used as standard, you'll almost certainly need a new one. The standard 075 really doesn't like being discharged, and it's rather underspec'd IMHO for the car in the first place. As such, if you keep it fully charged it'll probably last 4+ years, but if you let it discharge you'll really struggle to keep it alive.

If you can, replace it with a HSB075 from Bosch (Halfords do them - search for a "BMW 5 SERIES 1980/1981 (W) 518; 1766CC SOHC 8V CARB" on their online site and you'll find it).

It's a step up in cranking and absolute values (61AH/600A) from the normal HB075 (60/520) as well as suffering less from a discharge issue.

J

[Blu3R]

joust said:

Have you let the battery totally discharge (i.e. so it won't unlock the doors)?

If so, due to the battery used as standard, you'll almost certainly need a new one. The standard 075 really doesn't like being discharged, and it's rather underspec'd IMHO for the car in the first place. As such, if you keep it fully charged it'll probably last 4+ years, but if you let it discharge you'll really struggle to keep it alive.

If you can, replace it with a HSB075 from Bosch (Halfords do them - search for a "BMW 5 SERIES 1980/1981 (W) 518; 1766CC SOHC 8V CARB" on their online site and you'll find it).

It's a step up in cranking and absolute values (61AH/600A) from the normal HB075 (60/520) as well as suffering less from a discharge issue.

J

Excellent info, thanks! Something for the wiki I feel!!

[andygtt]

once they go flat they tend to be ruined... if you use the car a lot and so charge is going in and out they can last years and years.

I have the same issue on my M3... had it years and done loads of miles in it (170k now) and never had a single battery issue... turned it into a track car and so used much less, Ive now done around 3k miles in last 2 years and its on its 3rd battery!

[Gadgeroonie]

Joust - what do you think of those battery reconditioners used by workshops

are they expensive ?

[joust]

Gadgeroonie said:

Joust - what do you think of those battery reconditioners used by workshops
are they expensive ?

If you think you can "reverse" the rather simple chemical equation that happens when you drop below ~10V, then you should also buy that stuff that restores your hair.

Battery 'rejunivators' (spelling) that say they can reverse sulphation by sticking a whopping 16V across it will 'get you going', but they will never fix a duff battery long time.

The issue with the Noble is it takes a solid 0.1A, and worse if you have a tracker. On a 60Ah batteru therefore you have ~600 hours (or around 25 days) before the batter is below it's recovery voltage.

However, the cycling trickle charges, ala the Accumate (http://www.accumate.co.uk/it010003.htm) do actually have some science between them. They don't just "maintain" the charge, but they allow the battery to go through a decent discharge/recharge cycle.

One of them put on whilst it's in the garage with a Bosch Silver as above and you should be fine for 5+ years.

J

[les5709]

Thanks everyone for their input! i will get the battery tested up and see about getting another new one put in.