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| Thread ID: 110119 | 2010-06-04 02:33:00 | Car trouble! | george12 (7) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1106601 | 2010-06-07 00:35:00 | I read the document but did not try the start test, because I already know from the black indicator and low open-circuit voltage that the battery is low in charge. I did check the water levels and they appear OK, ie just below the bottom of the cap. Tomorrow I'll have a look around the house, chances are good that I'll have an old charger lying around somewhere. If so I'll charge it up then get it tested, if not I'll decide between buying a charger or just buying a new battery. However before I do anything I'll retest the alternator, as I never checked it with the engine revving above idle. If its normal it almost surely must be the battery, because it doesn't seem likely to me that a 40 minute drive at 14 volts (or even 13.8) is unable to replace the power used by a single second of cranking! your still mucking around with this ???? as far as alternators go. couple things to remember is that alternators only put out there "rated" output at high rpm's. at lower rpm's its a lot lower and that tends to be used by ignition system, stereo etc. so if your cruising around at low rpm battery gets bugger all charge back into it. eg from one of the manuals i have here. for a 60 amp alternator in a diesel (max rpm of 4000rpm) More than 17/1,300 More than 48/2,500 More than 57/5,000 petrol version 35amp alternator More than 27.5/2,500 petrol with 70amp alternator More than 14/1,300 More than 44/2,500 so if your cruising around at low speed and low rpm the output is only 14-20amp and the ignition system etc will take most if not all of that. if you sit at the lights/intersection your running off the battery. so you need to be doing 2500rpm constantly for a decent length of time to get any real charge back in. your vechile will be a bit different, it depends on what alt is fitted and how its geared. typically they are geared so max output is at max rpm so the alt isn't over revving at max engine speed. and thats for a good jap electrics, not a lucas ;) |
tweak'e (69) | ||
| 1106602 | 2010-06-07 03:33:00 | Only reason there's been any 'dithering around' is because some people have told me the battery is dead, replace it, others have told me its just flat, charge it. Thanks tweak'e, I did forget to check it with the engine revving above idle. However I don't think in my case it could be running off battery, cause if the battery nom voltage is 12.6, and the alternator is putting out 13.8 at idle, it may not be charging at max rate, but it's clearly not running off the battery. I don't like to spend >$100 on a car unless I am sure it will solve the problem. Anyway I'll go get the new battery today. |
george12 (7) | ||
| 1106603 | 2010-06-07 03:46:00 | Only reason there's been any 'dithering around' is because some people have told me the battery is dead, replace it, others have told me its just flat, charge it . Thanks tweak'e, I did forget to check it with the engine revving above idle . However I don't think in my case it could be running off battery, cause if the battery nom voltage is 12 . 6, and the alternator is putting out 13 . 8 at idle, it may not be charging at max rate, but it's clearly not running off the battery . I don't like to spend >$100 on a car unless I am sure it will solve the problem . Anyway I'll go get the new battery today . I think supercheap are doing $10 trade ins at the moment . |
plod (107) | ||
| 1106604 | 2010-06-07 03:51:00 | Cool, that's where I was going to go. | george12 (7) | ||
| 1106605 | 2010-06-07 03:54:00 | God about time. 99% of the time when the battery fails it is the battery nothing else. :) |
Trev (427) | ||
| 1106606 | 2010-06-07 06:11:00 | Only reason there's been any 'dithering around' is because some people have told me the battery is dead, replace it, others have told me its just flat, charge it . Thanks tweak'e, I did forget to check it with the engine revving above idle . However I don't think in my case it could be running off battery, cause if the battery nom voltage is 12 . 6, and the alternator is putting out 13 . 8 at idle, it may not be charging at max rate, but it's clearly not running off the battery . I don't like to spend >$100 on a car unless I am sure it will solve the problem . Anyway I'll go get the new battery today . so your going to buy a whole new battery because you can't be bothered charging up the old one :groan: your battery shows none of the typical signs of it being faulty . no corroded terminals, no loss of fluid . voltage is down but not low enough to suggest a dropped cell . a battery charger will last you far longer than any battery and you WILL use it more than once . it always pays to have a basic set of tools . the thing here is your going to be in this exact same situation every few years . its going to get expensive changing out all those perfectly good batteries . |
tweak'e (69) | ||
| 1106607 | 2010-06-07 06:22:00 | God about time. 99% of the time when the battery fails it is the battery nothing else. :) Not necessarily, especially if your car is fitted with a Lucas dynamo and regulator................:eek: Actually, I have had several alternator/rectifier diode problems over the years, and once bought a new battery because I didn't test things out properly. If the battery is low, revving the engine with lights on should brighten them, if not then the alternator or rectifier is likely at fault. |
Terry Porritt (14) | ||
| 1106608 | 2010-06-07 06:42:00 | so your going to buy a whole new battery because you can't be bothered charging up the old one :groan: your battery shows none of the typical signs of it being faulty. no corroded terminals, no loss of fluid. voltage is down but not low enough to suggest a dropped cell. a battery charger will last you far longer than any battery and you WILL use it more than once. it always pays to have a basic set of tools. the thing here is your going to be in this exact same situation every few years. its going to get expensive changing out all those perfectly good batteries. Well that's what I was thinking, but everyone else except you seemed to be laughing at my stupidity for not immediately replacing it.... Also the alternator was putting out a steady 14.5V at anything above 1000rpm which is a pretty good indication of a working charging system. Anyway as it turned out Supercheap did have a (very good) battery tester, which tests the battery, charging system, and for any current drains when the car is off. It said the battery is marginal and the charging system is fine, and there are no drains on the battery. The salesman suggested I just leave it for a while as it could be quite a lot longer till there are any issues starting the car - a good honest guy not just trying to make a sale! He suggested that a loose fuse may be at fault for the clock issue so I pulled out the fuse and gave it a bit of a scrape and put it back in. We will see what happens. And I do intend to charge the battery (he suggested this also to extend what life it has left). Anybody who is horrified by the fact that I didn't end up buying a new battery (yet) and thinks I'm an idiot or an 'old woman' is welcome to their opinion. However those people need to remember that I have NEVER had an issue starting the car, and the issues that prompted me to make this thread are far from classic bad-battery symptoms. |
george12 (7) | ||
| 1106609 | 2010-06-07 06:48:00 | Nothing wrong with reliability of Lucas generator and voltage regulator. Put out 22amps only thing that ever goes wrong with them is the brushes at about 150, 000 miles. At about the 500,000 miles a bush and bearing may be required. My mate owns a japper (never been a fan of them) its an Isuzu Bighorn the alternator crapped out when he was up north. It took a day to remove and refit the alternator and the alternator cost $450 for an exchange the mileage on the horn was 90,000 kilometres. I dont think the fault in Georges japper is the battery. Look for a bad connection on the main power wire. If a person who sells batteries tells you its marginal that really means its as good as new. |
prefect (6291) | ||
| 1106610 | 2010-06-07 07:42:00 | well thats good news :) least they didn't BS you into buying a new one because it might be faulty. the thing is you can get by with a poor battery for quite a long time. just charge it up every 6 months, you could get double the life out of the battery. thats saves you a fair bit of $$$. just think what its like for those with 4x4's, tractor, trucks etc where batteries cost a small fortune. i'm told those old dynamo's where good for batteries. the pulses they put out stop a lot of the sulphation. any truth to that ?? |
tweak'e (69) | ||
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