Discussion
I have a sick battery (only 2 yrs old and kept on mains conditioner) I will have to jump start to go to David Batty, I was looking at a battery start device at Argos for £46. Does anyone know whether these machines are big enough to fire up a 4.0 Chim? (Just seems easier than pushing it!)
Nessy said:
I have a sick battery (only 2 yrs old and kept on mains conditioner) I will have to jump start to go to David Batty, I was looking at a battery start device at Argos for £46. Does anyone know whether these machines are big enough to fire up a 4.0 Chim? (Just seems easier than pushing it!)
First, check your receipt - you may have a 3 year warranty. As for starting, the thing is cranking amps: I think 500-600 are required. But - if it starts your engine, you will then be b*uggered the first time you stop...
I bought one of those "Quick-Start" battery packs in the polyprop cover with handle and a built in light etc. It's made specifically for jumpstarting batteries and designed to sit on top of the battery (short leads). I balanced mine precariously on the r.h. rocker cover/inner wing and attached the *ve to the alternator "batt" and -ve to engine earth. With a stone-dead battery it cranked it over fine! I was very surprised - it cost me £30 from a Ford dealer.
the dodger said:
I bought one of those "Quick-Start" battery packs in the polyprop cover with handle and a built in light etc. It's made specifically for jumpstarting batteries and designed to sit on top of the battery (short leads). I balanced mine precariously on the r.h. rocker cover/inner wing and attached the *ve to the alternator "batt" and -ve to engine earth. With a stone-dead battery it cranked it over fine! I was very surprised - it cost me £30 from a Ford dealer.
Agreed used on my Chim last year a few times got mine from MACRO bargain at £14.99 plus the vodka and tonic
You need to be very careful when 'jump starting' flat batteries as an AA man (a very nice man as I seem to recollect) once told me. It's all to do with the ECU. When the good battery is attached to the bad battery and the car has been started, allow at least 10 minutes with both batteries connected before you remove the good one. If you don't, the alternator will 'see' (once the good battery has been disconnected) a very flat battery and will immediately ramp up the charging amps which has been known to blow ECUs. If you allow the 10 mins or so, it gives the flat battery chance to get some charge.
Having said all of that, you cannot charge a flat battery with an alternator, only with a dynamo. If your battery is flat, you'll need to get it on a proper charger and not just drive around the country side for an hour (though you could anyway as its FUN FUN FUN!!) Tech reason (oh wait - here come other opinions) being that the alternator senses voltage, dynamos sense current. A flat battery will be seen as a low voltage, alternator will increase the charging amps cos it can push lots in. The internal resistance of the battery times charging current (ohms law) gives a high terminal voltage. Alternator senses high voltage and reduced charging amps. Ah but!! you might say, doesn't it reach a happy medium and keep charging but at a slow rate? - apparantly not!! Best thing - as it's getting very close to winter - is change the battery. If you are in the AA, call them out as their batteries are cheaper than Halfwits and they come with a 5 year (YES 5 YEAR) garuntee, and they'll fit it for free (we they did mine!!)
Hope this helps.
Having said all of that, you cannot charge a flat battery with an alternator, only with a dynamo. If your battery is flat, you'll need to get it on a proper charger and not just drive around the country side for an hour (though you could anyway as its FUN FUN FUN!!) Tech reason (oh wait - here come other opinions) being that the alternator senses voltage, dynamos sense current. A flat battery will be seen as a low voltage, alternator will increase the charging amps cos it can push lots in. The internal resistance of the battery times charging current (ohms law) gives a high terminal voltage. Alternator senses high voltage and reduced charging amps. Ah but!! you might say, doesn't it reach a happy medium and keep charging but at a slow rate? - apparantly not!! Best thing - as it's getting very close to winter - is change the battery. If you are in the AA, call them out as their batteries are cheaper than Halfwits and they come with a 5 year (YES 5 YEAR) garuntee, and they'll fit it for free (we they did mine!!)
Hope this helps.
philip_cooke said:
If you are in the AA, call them out as their batteries are cheaper than Halfwits and they come with a 5 year (YES 5 YEAR) garuntee, and they'll fit it for free (we they did mine!!)
Hope this helps.
I was, and I did - except the chap didn't have the right size in his van and it was a Sunday so the place they use (Partco?) was shut. So after he'd jump started the car (Griff)I asked him if he'd mind awfully following me to Halfords so I could get a new one and could he change it over in the carpark...? He did, and it was well worth the £10 beer money.
Swapped e-mails with a friend of mine who's an electronics wizz. He said:
'...the job of the battery is to act as a store of enough energy to start the car. Once the engine is running, the Alternator/Generator provides the electrical power for the car systems. When the engine is running it just sits back and gets charged up again. That's what car batteries like best, deep discharge, followed by lots of charging. Alternators are more efficient than the older generators, able to provide a high output at low rpm, hence their use in modern cars. Any car battery will charge if energy is passing through it, whether it is coming from an alternator or generator. Given time the alternator will charge up the battery. I have done this. The interior light was left on in the Fiesta overnight and completely flattened the battery. One quick jump start and a few miles later, one charged battery.The other important job the battery does is to act as a very large capacitor, the effect is to regulate the alternator's output, ie smooth out voltage fluctuations. OK about the AA offering a 5yr guarantee, but are they twice the price? Even AA men must be on 'OTE' these days.
'...the job of the battery is to act as a store of enough energy to start the car. Once the engine is running, the Alternator/Generator provides the electrical power for the car systems. When the engine is running it just sits back and gets charged up again. That's what car batteries like best, deep discharge, followed by lots of charging. Alternators are more efficient than the older generators, able to provide a high output at low rpm, hence their use in modern cars. Any car battery will charge if energy is passing through it, whether it is coming from an alternator or generator. Given time the alternator will charge up the battery. I have done this. The interior light was left on in the Fiesta overnight and completely flattened the battery. One quick jump start and a few miles later, one charged battery.The other important job the battery does is to act as a very large capacitor, the effect is to regulate the alternator's output, ie smooth out voltage fluctuations. OK about the AA offering a 5yr guarantee, but are they twice the price? Even AA men must be on 'OTE' these days.
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