halford checked my battery and passed it , printed off reciept as pass.
voltage was 12.2v which i told em was not good and couldn't start the car.
they said it's almost as new. the amps rated at 440 and they passed it at 439.
they said it just needed a good charge.
so to check a battery properly you check it for ampage?
A load test looks at how the voltage holds up under load. A battery tester is basically a thick bar that gets rather hot and a volt meter.
was the battery in the car and being charged by the engine? if so when it's running the battery should be around 13.5v, if it is as low as you state then I'd suspect it isn't being charged sufficiently and it's not your battery at fault but the alternator. Why did you get the test done in the first place??
12.2V is perfectly normal for a part discharged battery, particularly if there was any load on it. You should have a round 13.5 - 14.0 V when the
battery is being charged by the alternator.
Modern battery testers are a bit more sophisticated than the type SJ talks about & do various tests, but particularly look at how voltage decays
while a heavy discharge is applied by the tester.
It's rare for a knackered battery not to show up as such on a modern tester such as I would expect Halfords to use 
quote:
Modern battery testers are a bit more sophisticated than the type SJ talks about & do various tests, but particularly look at how voltage decays while a heavy discharge is applied by the tester.
It's rare for a knackered battery not to show up as such on a modern tester such as I would expect Halfords to use
quote:
Originally posted by SJ
quote:
Modern battery testers are a bit more sophisticated than the type SJ talks about & do various tests, but particularly look at how voltage decays while a heavy discharge is applied by the tester.
It's rare for a knackered battery not to show up as such on a modern tester such as I would expect Halfords to use
I don't do sophisticated!
as Halfrauds main mission is to sell you stuff you may or may not need, i imagine the battery is ok, try checking for dodgy conexions and give the
battery a nice long slow charge.
quote:
quote:
Originally posted by SJ
quote:
Modern battery testers are a bit more sophisticated than the type SJ talks about & do various tests, but particularly look at how voltage decays while a heavy discharge is applied by the tester.
It's rare for a knackered battery not to show up as such on a modern tester such as I would expect Halfords to use
I don't do sophisticated!
You drink wine from a mug?
The old fashioned home battery test used to be measure the battery voltage in the car (engine off) then put the full beam on and see what happens.
Knackered battery would see a big voltage drop.
But agreed the old fashioned "controlled short circuit" tester is reassuringly brutal and impossible to fool.
quote:
Originally posted by cliftyhanger
... reassuringly brutal
quote:
Originally posted by Angel Acevedo
quote:
Originally posted by cliftyhanger
... reassuringly brutal
I like that.
I wonder how many batteries have exploded using one.
Halford will have use a solid state impedance tester on the battery this estimates the life left in thr battery and CCA
Battery tests these days don't involve a very heavy load on the battery . AC impedance testers can be used on parially discharged batteries.
Althougn if the battery is suspect and passes an AC impedance test I would follow up wiith a high load volts drop test at 40% of the rated CCA of the
battery.
However 12.2v indicates the the battery needs charged ---- ie an alternator fault or electrical drain has flattened the battery. With no load on it a
good in service battery should show at least 12.4v in current UK weather conditions
Autool Battery Tester Amazon UK
[Edited on 26/2/19 by britishtrident]
First of all I feel happy, with the help of guys such as you on internet, I took my car out after two years of building it. I was nervous has heck
but went allright . Ran it for 5 minutes but the problem with the hot start was still there but won't let that ruin my day.
Okay so I can repeat this fault as follows;
The car is fully charged with trickle charge to 13.5V
Start cold engine: shows 14V on gauge to prove alternator is working
While driving around it is 13.7V, when fan kicks in, it's 13.6V.
Get engine to operating temperature, which happens pretty quick , so im assuming it's a "tight'" engine.
after 5 minutes drive (I know it's not enough but shouldn't be that drained from full to not start a car twice) stop car and try to
re-start. Struggling to turn crank, can't start.
Put trickle charger back, shows 12V on charger gauge. Charge it up to 13V on trickle charger.
Time to try to start HOT engine, and turns crank n starts.
The modifications that have taken place that can affect the start;
1.4L to 1.6L displacement.
Race/Road cam installed with new springs n lifters.
New bearings, pistons, rings etc
After getting the car boot have you tried leaving the car for 5 minutes before cranking? Then leave it for 30 minutes and try cranking.
I'm wondering if you have fuel vaporisation or something not related to the battery.
[Edited on 18/5/19 by MikeR]
quote:
Originally posted by MikeR
After getting the car boot have you tried leaving the car for 5 minutes before cranking? Then leave it for 30 minutes and try cranking.
I'm wondering if you have fuel vaporisation or something not related to the battery.
[Edited on 18/5/19 by MikeR]
Had same problem with mine - geared starter motor solved it. Can now start a stinking hot high compression V8 with a motorbike battery
got a stronger battery with more cca but same thing happened.
okay im not driving it along time. 6-10 minutes and i know new batteries need a good charge but im noticing the the voltage drops from 14.4-14.7v to
13.6V-13.1V after the engine temperature gets up to 90C. starts to drop. so dont think its enything to do with tight engine because as soon as i put
trickly charger on the battery, it fires up the engine instantly.
new alternator, new starter motor, new batteries. so now new cables?
Do you have the old battery?
I'm thinking put the old battery on charge, drive the car, come back and quickly swap batteries. Now try to start the car.
It will prove its a charging problem. I think it still won't start so the problem is elsewhere.
yeah ive got two new batteries now.
but the time it takes for to swap battery is about 3 minutes.
i used a mains trickle charger and in 3-5 minutes charged battery up to start engine.
problem was negative battery lead that goes to gearbox . was a cut in it , where the cut was only half of the wires there.