In Waitrose car park. Engine wouldn't turnover. The battery had been playing up recently but I hadn't expected a total collapse. Thankfully, had jump leads in boot. Who to ask for help? I am not sexist, but stopping elderly ladies as they drive in didn't seem the right way to go. Man One - battery is in the back but don't know where. Man Two - was prepared to help but his car was new and we couldn't find the battery under the bonnet. Man Three knew his stuff-"battery is in the back but there are terminals under the bonnet." - and we then had car started in 30 seconds.
Replaced battery and car starts and drives like new. It is an auto i10 and had been running a little rough at low speed but I hadn't suspected the battery as causing the problem. I guess at low revs the alternator voltage is not enough - or the faulty battery was demanding all the available current.
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always ask a bloke.
i'am also running a i 10 auto 59 plate 60k still on original battery
next door neighbour done some electronic damage to his fiesta doing a jump start badly
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>> next door neighbour done some electronic damage to his fiesta doing a jump start
>> badly
>>
Indeed, and not even badly. My own car is an older C Class and they're notorious for frying the front SAM (signal acquisition box, a sort of junction/control box for everything in the front of the car) while either being jump started or using the car to jump another.
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>>next door neighbour done some electronic damage to his fiesta doing a jump start badly
>>
To state the obvious RTFM.
You may be surprised at what to do and what not to do, I was.
I am referring to 10/15 year old Fords not some exotic machine.
All about not causing damage.
I guess one other example from the past - connect the negative cable to the block.
IIRC some cars have two batteries, one dedicated to starting the engine.
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What processes do the team use to "jump start" a car?
In the old days I was taught to connect the cars batteries (+ to +. - to - assuming same earth) and start faulty car.
This was updated, at least 20 years ago, to connect as above then
start good car , rev like worst for 3-4 minutes to put some juice into faulty battery, switch off good car, disconnect leads, start faulty car
updates?
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>>updates?
Seriously, best RTFM.
IIRC Ford was something like switch on the HRW NOT the lights before disconnecting.
Not the sort of thing to guess :-)
I think connecting neg to the block was all about eliminating any loss between battery and spark plugs.
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p.s.
Battery talk has reminded me to attend to the recommended three monthly top up my pocket sized lithium battery powered jump starter.
RTFM reminds me to disconnect it within 30 seconds of starting the car.
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>>I think connecting neg to the block was all about eliminating any loss between battery and spark plugs.
I thought it was more to do with avoiding sparks caused by connecting/disconnecting igniting any hydrogen gas being vented from the battery.
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>> Man 3 had a BMW !
I so hope he was called Harry...
;-)
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Man one did too I think but was clueless.
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Man 3 did indeed have a BMW.
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Definitely connect negative to block, I heard it was to prevent the electronics being fried.
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The key to no damage is to leave donor car switched off, if it has a healthy battery if should start fine ...
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It says in my handbook in order to avoid excess voltage in the electrical system, before removing a jump lead, switch on an electrical consumer (e.g. lights, heated rear window) in the vehicle receiving the jump start.
As Henry quite rightly said, RTFM. Each vehicle will have a different recommended procedure. Better that than frying the ECU or one of the Canbus systems.
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>> Definitely connect negative to block, I heard it was to prevent the electronics being fried.
Nope, it's to avoid accidentally short circuiting the leads together, or creating a spark near any possible venting hydrogen gas from the battery.
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>> The battery had been playing up recently but
>> I hadn't expected a total collapse.
Yup thats the tale of modern car electrical systems. Battery will give you a couple of gentle warning signs then just completely give up the ghost.
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That has been my experience. Two warnings and then it is zapped.
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In my experience, older cars = adequate warning, newer cars = no warning.
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Diesels are worse than petrol in my experience.
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I once owned a 15-yr old Nissan Sunny with 138,000 miles which was on original battery - which I managed to drain by not closing the boot lid properly (no indication on dashboard) thus keeping the boot light on for days!
Bought the car for £300 and after 6 months sold for £350 (only expense was replacing the battery - which was my fault).
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Our 120i is 12 years old, on 104k and on its original battery. The BMW charging system is clever, varying the charge rate, only charging on the over-run etc.
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>> Diesels are worse than petrol in my experience.
>>
They have higher compression ratios so take more current to turn over.
Incidentally I've never understood the advice to have the donor car running. If the donor battery can start its own engine it can easily start the other one, so what's the point?
And how can the precious electronics in the other can "know" where the juice is coming from? If you replaced the flat battery with a new one it would cope, obviously.
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>> Incidentally I've never understood the advice to have the donor car running. If the donor
>> battery can start its own engine it can easily start the other one, so what's
>> the point?
There is higher voltage at the donor car battery with the engine running, which helps to overcome the resistance at the relatively poor jump lead connections.
The main problem is that most people have crap jump leads.
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>>
>> There is higher voltage at the donor car battery with the engine running, which helps
>> to overcome the resistance at the relatively poor jump lead connections.
>>
I don't think it's voltage that matters but the ability to deliver current. A modern alternator going flat out might possibly contribute 100 amps. But if the battery is any good it can easily manage the 400 amps needed to turn the engine - that's what it does every time it starts its own engine.
A big battery half flat may only measure 12 volts, but that doesn't mean it can't start an engine. Or to take an alternative extreme case, you could couple ten 1.5 volt torch batteries in series have a nominal 15 volts - but it wouldn't turn a starter motor.
I agree about the jump leads though - whatever source of power you have, the supply won't get through if the connection is poor.
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>>
>> >>
>> >> There is higher voltage at the donor car battery with the engine running, which
>> helps
>> >> to overcome the resistance at the relatively poor jump lead connections.
>> >>
>>
>> I don't think it's voltage that matters but the ability to deliver current.
A starter motor needs Watts, More voltage the less the current required. The less current the less the loss over poor connections,
As many volts as you can muster please. 13.8 over 12 much more preferable in times of stress.
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Flat battery - slowdown avenue
