Conference terri::cars_uk

    Just to revive this topic. I replaced the battery in the Triumph
    Acclaim this week. Not much choice really, as it wouldn't start any
    more. I can't complain as we've had the car over 2 and a half years.
    Anyway, am I imagining things or does that car actually run smoother
    and better with a new battery. I can sort of figure it out. If the old
    battery was sucking up power off the alternator, then presumably the
    spark plugs weren't being supplied with as strong a jolt. Does this
    seem sensible? If so, then it would also explain why the stereo is now
    so much louder too.=:^>
    
    Tim

re: 607.6

My card half died on the ferry to England (auto box duff)
so I "limped" into the customs hall 15 mins after everyone else ...

... got the full drugs search treatment ... took 2 hours ... drug dog,
measuring full tank inside and out, x-rayed tyres, ripped out seats & panels,
fibre optic probed engine cyclinders and sump .... ho, humm.

So: make sure you car is 100% normal when going through customs ...

Richard

>>  <<< Note 607.12 by MUDIS3::VUSCLU::HATHWAY "Richard Hathway - Munich MFR" >>>
>>                         -< Duff car=customs search? >-

>>ripped out seats & panels,

    I've often wondered about this, did they put it all back PROFESSIONALLY
    afterwards?. 
    
    
    What was they're attitude to you whilst this was going on?
    
Richard
    

    Had an interesting problem with the battery on Management's car
    recently .. it behaved as if it had grown internal diodes.
    
    Every couple of weeks or so, there would be panic stations in the
    morning as she was leaving for work 'cos the car wouldn't start due to
    flat battery. It would bump-start OK and last out the day until arrival
    home in the evening, when an overnight charge seemed to put things
    right. I did notice - courtesy of the trusty old AVO Model 8 - that the
    charge current was only 1.5 amps. I put this down to the fact that I
    was using a constant voltage regulated supply set to about 13.6 volts
    (normally used for powering assorted bits of electronic and radio kit)
    rather than a battery-charger, which I don't have.
    
    Unfortunately, after about a fortnight, we had to go through the whole
    thing again. After the third such occasion, I had the battery tested
    with one of those big_prod_with_shorting_coil_and_meter thingummies and
    it was pronounced very healthy. We still had the trouble come back
    again, though.
    
    In an attempt to check alternator output ('cos that was beginning to
    look to be the culprit) the aforementioned trusty AVO meter registered
    a whole 2 amps going into the battery. It seemed pretty conclusive, but
    for some odd reason, if the alternator really WAS at fault, I couldn't
    explain why the interior light didn't dim, or the heater blower didn't
    slow down when I switched on the rear screen heater and headlamps (with
    the battery in its discharged state, of course!).
    
    So, before rushing off to buy a recon. alternator, I temporarily
    substituted the battery from my leasemobile and to my surprise,
    registered the charging current at about 4 amps at idle. Management's
    battery fitted temporarily to MY car charged nicely at 2 amps whatever
    the engine revs!
    
    Clearly, her battery had got itself into a state where it had a high
    resistance to charging current but would deliver hundreds of amps on
    demand to turn starter motors and cause shorting coils on tester
    thingies to glow red hot if left too long.
    
    Can lead acid accumulators really do that? It was on an 'H'-registered
    motor with 15K miles on the clock.
    
    A new battery has solved her problem but I am intrigued as to the cause
    of the fault.
    
    Any ideas?
    
    Is there anything I can to to rejuvenate the old battery, even for a
    less demanding application, perhaps?
    
    "Puzzled" of Welwyn.
    

    Sounds EXACTLY the same problem I had on my old (H reg) Astra GTE.. the
    car would be ok during the day but probably wouldnt start the next
    morning.. and definitely wouldnt start if left unused for a weekend.
    The garage blamed, my driving lamps, alarm, phone.....etc...etc and
    wouldnt replace it... Till one day I got so p****d off bump starting in
    the rain I drove straight to kwik-fit who promptly tested it with their
    gizmo and said "yer batteries knackered... y' need a new ane!!"
    
    End of problem... it worked fine for evermore......
    
    Dave.

    The battery on our 7 year old Corrola just gave up the ghost. I've a
    spare battery which had only been used for a couple of months in an 
    old car, it is "rated" 40Ah. Checking in the Haynes manual it mentioned
    60Ah for the Corrola! I've had to install the spare battery this
    morning so my wife can use the car.... 
    
    What could/may happen (to the car, electrics or battery) if you use
    such a battery which has a "lower" rating?

    re .18
    
    Should not be much of a problem.
    
    The battery will go flat quicker when the engine is not charging it,
    but that should not be significant if the car starts well normally and
    you dont have a problem with the charging circuit.
    
    The battery may have a lower current capacity, which would make the
    volts drop off too much when trying to start the engine. This may make
    cold weather starting difficult. Your starter motor is unlikely to use
    so much current that it would damage the battery in normal use. It may
    make it heat up a bit too much in really hot weather if you crank the
    engine for a long time. But if the car normally starts well then you
    shouldn't come across this.
    
    Its probably best to get the right size battery, but you could keep on
    using the spare until you get one.
    
    Andrew

    If the charging circuit is designed for 60Ah, you may end up
    "overcharging" a 40Ah - there's not much difference between the two
    tho, so it'll probably reduce the life of the battery rather than wreck
    it straight away.
    
    Andy
    

    Thanks for the 2 replies. The car starts quickly (normally) everytime
    so there shouldn't be any problems with it getting drained/hot etc.

The Battery charging system works against the Battery voltage and that will be 
the same relative to the state of charge whichever Battery is fitted.

The only problem would be in starting the engine, if the engine starts easily,
that problem will not be apparent.

				Malcolm.

    
    Beg to differ,
    car requires 60Ah battery, read... is capable of delivering 60 Amps per
    hour continuously and normally something like 350 Amps over short
    periods over different temperature ranges.
    
    Install 40Ah battery....charging remains the same, alternators only
    require a load to do their business (which is why you should never
    disconnnect the battery once the engine is started)
    
    The problem is the construction of the battery, they all (12v) have the
    same number of cells but quite different size and quality of
    conductors.
    So, install a SMALL battery... ie, one which is less capable of
    sustaining high current... at fire up time, and the conductors heat up,
    bend and eventually go open circuit. Result, one very dead battery.
    If you don't believe it I've got one at home which did exactly that.
    It was a very lively battery in the little Mazda but two months after
    being installed in a V6, with no problems in between, it suddenly went
    completely open circuit.
    
    Note that the batterys charge state is not relevant to its size but
    given the same load both batteries would drain at the same rate, except
    that the lower rated one when drained beyond it's capability, will
    deteriorate much quicker than it's big brother.

    RE: .23
    
    So would you say I could end up with a problem if I have a 40Ah battery
    in place of a 60Ah version with a car that starts quickly 95% of the
    time, and for the other 5% it's still only a matter of seconds...?

	I'm very sorry to notice your lack of electrical knowledge!

	The Ah rating of a battery means, which you obviously don't realise, 
that in the case of 60 Ah, the Battery will (if fully charged and in reasonable 
"nick") supply 60 Amperes for 1 hour, 1 Ampere for 60 hours, 5 Amperes for 12
hours etc. etc. before it needs to be recharged, during which time the on-load 
terminal voltage will drop from a nominal 2.2 volts per cell to a nominal 1.8 
volts per cell.  It is this voltage which the charging circuits sense in order 
to adjust the charging current to keep the battery fully charged during normal
operation of a car, this current/voltage is independent of the battery capacity!

	Hence, if the car is in reasonable "nick" and starts promptly, fitting 
a different capacity battery (within sensible limits, of course!) will not 
provide any problems, certainly NOT in the short term.

	Obviously, a 5 Ah Battery would not be within "sensible limits," but
40Ah is.

	End of discussion?

				Malcolm.

     I'm very sorry to notice your lack of the English language.
    
    Pompous twat!!
    
    In my reply, I made no attempt explain the charging requirement of
    continuous drain on the different batteries. The charge or discharge
    rate is of no consequence to the question, except that is, if the car
    was continually cranked to start it. Which would drain the smaller
    battery quicker. And, on the assumption that the alternator is the
    correct one for the car, I doubt that enough current can be drawn from
    the battery while the engine is running, to cause it to discharge.
    
    Are you with it this far Malcolm, good.
    
    The issue is not one of whether the battery requires recharge more
    often than say a 60Ah battery.
    
    Lets get basic, small car, small battery "40Ah", cold start requires
    lets say 250 amps. Large car, large engine, more cold oil, more pulleys
    perhaps, small battery "40Ah", requires say 350 amps to crank it.
    Note, the current drawn at startup time is a guess and may well be
    substantially less but it illustrates the point.
    
    Both batteries are obviously capable of turning and starting the car
    very efficiently but guess which one will (fact) breakdown first due to
    continual stress at start time?
    
    So, Dave, apologies for the side track, the small battery will work
    fine and providing you do not have to overcrank the engine may well be
    o.k. for a long time. Just don't leave things like heated screens on
    when you start the engine from cold.
    
    Bill
    

    RE: .26
    
    Bill,
    
    >>			Just don't leave things like heated screens on
    >>when you start the engine from cold.
    
    Oh you've met the wife! Blowers, screen heaters... you name it :-)
    
    Dave

    Some sanity perhaps
    
    Some years ago my Sunbeam Ti suffered from flat batteries, I changed
    everything I could think of, new heavy duty alternator (big Cibies),
    bigger battery, coil, several wires etc etc etc. Then somebody said to
    check the earth which ran round the body. By this time the Bumseam was
    getting tired and a little rust creeping in and yes the earth was very
    poor. A braided cable from the block direct to the battery cured
    everything thanks to my local motor factor.
    
    I believe Minis used to suffer from this too.

    
    > I believe Minis used to suffer from this too.
    
    Yes.  They'd also lose the earth connection to the engine.  The engine
    would instead get it's earth from the metal cable that operated the
    heater hot water valve.  This would weld itself together as it couldn't
    cope with the current flow.
    
    My Metro recently did a similar trick, the earth to the engine was OK
    but to chassis was very poor.  The car ended up earthing itself through
    the speedo cable, causing the dashboard lights to illuminate *very*
    brightly and everything else to go to a faint glimmer.
    
    Ian
    

I'm glad that you finally got around to agreeing with me in your last
paragraph, Bill.

	And thanks for the compliment, too.

				Malcolm.

If it was a VW I'd say replace the regulator.

The regulator is positioned on the back of the altenator, in the perfect 
position for oil to drip onto it when the head gasket blows.

Needless to say regulators don't like working with oil.   The symptoms are:


fine when cold
battery doesn't appear to hold a charge
testing on regulator shows nothing wrong (done when cold of course)
all batteries appear duff after about a month
car won't operate for long when using anything like wipers etc.

    No problem Malcolm, one complement deserves another!
    
    And no I didn't agree with you, because although your reply does say
    that it will be o.k. providing the car starts quickly you didn't say what
    would happen if it didn't, but then maybe you didn't know!
    
    

    
    No I don't believe that for a minute Malcolm.