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Sept 12, 2011 15:03:44 GMT
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A mate owns a garage and sells batteries for £5 each. I bought one recently, and it was dead, battery on charge over night, and it lasted about two seconds trying to start the car.
I changed it for another one, and it was also dead - so I put it on charge, and the charger says it's charged. A quick bridge with a cable and no sparks, etc. Does anyone know why it's doing this - the battery is recent, and I'm thinking maybe the charger is at fault?
In the meantime, I think I'll buy a new battery.
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Sept 12, 2011 17:10:17 GMT
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Could be, need to test the battery with a meter.
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ChasR
RR Helper
motivation
Posts: 10,307
Club RR Member Number: 170
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Sept 12, 2011 18:05:47 GMT
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When I have had this happen it is generally down to the battery being on the verge of going/dying completely. I probably should not have done this, but taking the charger clip on an off seemed to make the charger 'think' it was fine.
However, secondhand batteries can be a lottery, depending on how the PO maintained his car (I have killed a Bosch Silvertop once in 8 months from when I bought it new... (That car did have the alternator die on it twice mind you)).
On the other hand, the 'B was fine on and 'old' battery (it was from a friend which I knew to be a good battery and recently new (he smashed his car up)).
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Last Edit: Sept 12, 2011 18:08:01 GMT by ChasR
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Sept 12, 2011 18:42:52 GMT
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You really need to hit a used battery with a heavy discharge tester to find out if its any good
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Sept 13, 2011 4:58:52 GMT
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I find that when a battery is properly, properly flat, there isn't enough charge in it to register with the charger that there's even a connection. An overnight spell connected to a good battery with some jump leads, gives it enough life to register on the charger and take a charge.
Also check the electrolyte level if it isn't a sealed batt.
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Sept 13, 2011 8:20:09 GMT
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I find that when a battery is properly, properly flat, there isn't enough charge in it to register with the charger that there's even a connection. An overnight spell connected to a good battery with some jump leads, gives it enough life to register on the charger and take a charge. Also check the electrolyte level if it isn't a sealed batt. You can just connect jump leads to the battery while its on charge, that sometimes gets them to take a charge, even if it is a sealed (not gel) battery you can sometimes lift the lids and check the water level, found that they were usually virtually empty on J imports straight off the docks, topping them back up saved some of them |
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Sept 13, 2011 8:36:46 GMT
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If an old battery has been standing for a while and won't hold a charge, you can kick it back to life by briefly putting 24v on it a couple of times. This will de-sulfate the plates making the battery hold a charge again. Mind you, this won't work everytime and it may not work for a long time, but if you need to use an old battery, and since it was dead anyway, it's worth a shot.
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Sept 13, 2011 16:02:40 GMT
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Where do you get 24v from though? I never thought about the charger not registering the battery on 0v!
I left it going overnight, it was still on red (not charged yet) at about 7am, but at 12 noon, it had the green light (it's ready!). It turned the engine, and it's not yet done that slowing down thing, so I suppose it had just lost it's charge from being in a scrap car.
Can you get distilled water from cooled down boiled water? I haven't check the level yet.
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Sept 13, 2011 22:43:13 GMT
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You can get distilled water from all the big supermarkets and motor factors. Cooled down boiled water still has the minerals in it that can damage the battery, but to top up an old battery i would use the free stuff out the tap
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I don't WANT TO DIE A GROWN UP!
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ChasR
RR Helper
motivation
Posts: 10,307
Club RR Member Number: 170
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Sept 14, 2011 13:40:41 GMT
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One thing to remember is that most batteries are maintenance free these days meaning that sometimes the battery may be completely sealed.
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Sept 14, 2011 21:49:33 GMT
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Batteries that have sat for any length of time when nearly or completely flat will have sulphated plates. They can show a reasonable voltage in this condition but won't manage any current as the sulphated plates make them act as a much smaller battery. They will also appear charged when placed on charge as they will also be unable to accept much current.
Adding EDTA sometimes helps. Discharging them very slowly (5w bulb) and trickle charging sometimes helps a bit. Basically, once they get like this they are knackered though.
Nick
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1967 Triumph Vitesse convertible (old friend)
1996 Audi A6 2.5 TDI Avant (still durability testing)
1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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Sept 18, 2011 10:04:02 GMT
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Hmmm- it sounds like your mate is selling scrap batteries for a premium price  |
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ChasR
RR Helper
motivation
Posts: 10,307
Club RR Member Number: 170
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Sept 18, 2011 12:01:15 GMT
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It is not the first time I have seen garages/scrappies doing this TBH.
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