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| Thread ID: 104594 | 2009-11-02 02:33:00 | Diagnosing strange car problem - ideas? | forrest44 (754) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 826396 | 2009-11-02 03:49:00 | Try it, tell us what happens after :p | Speedy Gonzales (78) | ||
| 826397 | 2009-11-02 03:50:00 | Back in the bad old days when you thought yourself lucky if your Lucas battery made at the Foremans Road works lasted 2 years, and when the cells were connected by exposed thick lead mouldings on top, the battery shops had testers. These had two pointed cad. plated prongs joined by a thick shunt and connected to a meter with the scale going from red to green.....and a wooden handle to hold it. There were also acid density testers, made of glass, with a float and a rubber bulb to draw the acid in. Each cell was tested in turn discharging umpteen amps into the tester. When batteries went down and wouldn't hold charge, it was often found for some reason to be an end cell that had failed. Penniless motorbike riders would chip the pitch out of the top of their 6v battery, remove the plates, clean the sludge out from the bottom, replace the plates, and pour molten pitch back to seal it all up and add new acid. This would often give a bit more life. |
Terry Porritt (14) | ||
| 826398 | 2009-11-02 03:58:00 | Try it, tell us what happens after :p I think il stick to rum for now, when I run out I might head out and give it a shot. *remember to buy some straws* |
hueybot3000 (3646) | ||
| 826399 | 2009-11-02 04:10:00 | with a multimeter, and last time the problem happened it was not flat Might depend exactly where you test the battery, either at the posts or on the clamps/terminals. There should be minimal difference in volts. To load test a battery, you can check the voltage drop whilst the engine is started - should be less than about 9.6 V as explained here (www3.telus.net)... |
kahawai chaser (3545) | ||
| 826400 | 2009-11-02 04:16:00 | What you want to do it have someone hold a multimeter on the battery terminals while you are cranking the car over. Should be 11.5v - 12.5v when sitting, down a couple when cranking. If it's down to like 4v - 8v then the battery is flat/stuffed. Check each cell, see if the water level is too low or if any one of them is bubbling. If the voltage is fine the check leads/clamps. Maybe replace any dodgy looking ones. |
wratterus (105) | ||
| 826401 | 2009-11-02 04:33:00 | "it was often found for some reason to be an end cell that had failed" That is because these are the cells that experience the most temperature variation during their life, normally the end facing the engine or radiator fails first, also the end exposed to the weather most. |
zqwerty (97) | ||
| 826402 | 2009-11-02 04:44:00 | and use NO OILS, SALVES OR OINTMENTS on the battery posts at all Why SJ? I've always smeared Vaseline or similar over the terminals before reconnecting the leads to ward off corrosion. And I've been doing it for 20+ years, and no ill-effects. However, that's NOT to say it's a smart thing to do! :confused: Look forward to your explanation with interest. |
allblack (6574) | ||
| 826403 | 2009-11-02 05:09:00 | These had two pointed cad. plated prongs joined by a thick shunt and connected to a meter with the scale going from red to green.....and a wooden handle to hold it. :eek::eek::eek: Each cell was tested in turn discharging umpteen amps into the tester (usually 300-600amps from an average car battery, divided by 3 or 6). If you ever see one of these, throw it in the rubbish bin/trash, they are extremely dangerous, because as you are shorting out the cell (or whole battery (you could get 12 or 24v testers also)), the cell/battery will discharge large amounts of hydrogen gas which will explode violently if you produce a spark as you disconnect the tester usually blowing the battery into pieces and showering you with acid (which will go in your eyes, because you were looking at the tester), I've seen this happen; you stand a good chance of getting burnt by the red-hot shunt too. Also not a good idea to wear jewellery near a car battery either, for similar reasons. The modern testers with the shunt inside a box, with short leads and a button or switch to test, are much safer. |
feersumendjinn (64) | ||
| 826404 | 2009-11-02 06:01:00 | Why SJ? I've always smeared Vaseline or similar over the terminals before reconnecting the leads to ward off corrosion . And I've been doing it for 20+ years, and no ill-effects . However, that's NOT to say it's a smart thing to do! :confused: Look forward to your explanation with interest . Many of us got away with malformed ideas - but the "olden days" had pitch-topped cells as noted above and they had a bad tendency to bubble acid out of the cells through the cap/vents and then the vapors would attack the posts and render them corroded and not much good for electrical conductivity - quickly . The vapors of the liberated electrolyte were kept from making contact and condensing on the metallic parts on the top of the battery - and you'd use a grease to keep them sealed and isolated . That was all well and good - THEN . Today's batteries don't out-gas like that as they have a neat device on top of the cells where the water goes - that distill and return the vapors to the cell itself - rendering the newer batteries "service-free" or so since they required less attention and not so constant water refilling during the life of the battery . IF there's a lot of out-gassing - then something's wrong and (either) the voltage regulator is whacky or a cell has gone bad and is no longer working as it should and just boils the water/electrolyte out of that particular cell . As a sidebar: If the alternator is passing alternating current to the battery and not clean, flat, non-malformed electricity, then the cells can liberate a lot of hydrogen and that can cause a lot of corrosion . Any leakage and loss of electrolyte is reason for suspecting another dynamic is taking place . Using jells, salves or holy balms just masks the problem if one even exists, and may work it's way between the post and the lead connector, causing severe loss of current carrying capacity - making one think their battery is dying or weak . Putting those prophylactics BETWEEN THE POST AND THE CABLE END is not a good idea as that reduces the contact area of the aforementioned parts and can set up a lot of heat/resistance and loss of cranking power . The GM side post batteries have usually failed from over tightening the bolt that holds the connector and it pulls the post out of the battery, ruining the seal and watertight integrity . Really - the best service one can give a battery is to periodically check the electrolyte level - even in the "service-free" ones, and topping it up as needed and whilst the engine's idling, just run the garden hose gently over the top of the battery passing from the negative to the positive post and repeating that action until the battery is clean and sparkles . The alternator will produce current over the top of the battery this way and actually erode the corrosion - if any exists at all - from the top of the battery and the posts themselves . Electrolyte leaks are a sign of loss of watertight integrity, not necessarily of a problem with the charge rate/capacity - but it MAY also indicate some warnings to watch the battery for more and future untoward activity . BTW: Most modern "never-needs-service" and sealed units die at about three years anyway . Reality-wise - you just rent a battery for the duration and when it poops out, you rent another one . |
SurferJoe46 (51) | ||
| 826405 | 2009-11-02 06:24:00 | In NZ we put lanolin/ petroleum jelly or vaseline on the battery posts always have always will. | prefect (6291) | ||
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