FLAT BATTERY OR GOING FLAT?
08 January 2016, 12:41 PM
#1
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FLAT BATTERY OR GOING FLAT?
Went to start my Hawkeye Sti this morning and car wouldn't start. It wasn't turning over and alarm kept going off when I tried. Car has been stood idle for a while as I have been on hols for around a week or so. Any ideas as I'm gunna have to get it sorted after work. Thanks in advance.
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09 January 2016, 04:37 PM
#12
Originally Posted by alcazar
Are you certain your alternator is OK? And/or a "smart" one? If it's smart, run for a while with inside fans on fast, or hrw on.
What do you mean by and or a smart one?
09 January 2016, 09:13 PM
#13
Some newage cars are fitted with a so-called "smart alternator" which only produces a charging current when there is a load across it, ie: when something is switched on, hrw, internal fans, headlights etc etc.
The problem was that, with short journeys in summer, none of those, so the battery ended up flat.
You can check with a multimeter: mine shows 13V or so across battery, 14.4 when alternator is charging.
A smart alternator wouldn't show any more voltage, until you switched on the lights etc. Then it would.
The problem was that, with short journeys in summer, none of those, so the battery ended up flat.
You can check with a multimeter: mine shows 13V or so across battery, 14.4 when alternator is charging.
A smart alternator wouldn't show any more voltage, until you switched on the lights etc. Then it would.
10 January 2016, 06:27 PM
#15
I also have a blob STi (JDM) and I don't believe it has a smart alternator.
Battery on mine used to die after a week and I traced it to the tracker - the backup batteries in these start to take an excessive current after a few years. 0.3A in my case which is enough to kill the battery. Removed tracker and all was good...
...until a year ago when battery would go flat after just a couple of days. New battery didn't fix it so I again spent time trying to track down any current drain. I was seeing just 80mA, and half this was my Toucan: but leaving the Toucan disconnected made no difference.
I have still not tracked it down - 40-80mA should not drain a battery after a few days so I think something randomly starts to draw excessive current after a while. Or it's something I missed.
For example, I do still have a Toad alarm installed, but disconnecting the siren (with it's back up battery) made no difference so it could be the Toad control unit itself, or the separate anti-hijack system. Or the sound system. These are all wired on their own in-line fuses (so bypass the usual fusebox, which is where I went through fuses one by one to try and track down excessive current drain).
I just haven't had the time to investigate further.
Too busy wiring up other people's cars lol.
10 January 2016, 08:38 PM
#16
No - not overnight: that will flatten the battery! If it's a smart alternator you switch something on while the engine's running to get it to charge.
I also have a blob STi (JDM) and I don't believe it has a smart alternator.
Battery on mine used to die after a week and I traced it to the tracker - the backup batteries in these start to take an excessive current after a few years. 0.3A in my case which is enough to kill the battery. Removed tracker and all was good...
...until a year ago when battery would go flat after just a couple of days. New battery didn't fix it so I again spent time trying to track down any current drain. I was seeing just 80mA, and half this was my Toucan: but leaving the Toucan disconnected made no difference.
I have still not tracked it down - 40-80mA should not drain a battery after a few days so I think something randomly starts to draw excessive current after a while. Or it's something I missed.
For example, I do still have a Toad alarm installed, but disconnecting the siren (with it's back up battery) made no difference so it could be the Toad control unit itself, or the separate anti-hijack system. Or the sound system. These are all wired on their own in-line fuses (so bypass the usual fusebox, which is where I went through fuses one by one to try and track down excessive current drain).
I just haven't had the time to investigate further.
Too busy wiring up other people's cars lol.
I also have a blob STi (JDM) and I don't believe it has a smart alternator.
Battery on mine used to die after a week and I traced it to the tracker - the backup batteries in these start to take an excessive current after a few years. 0.3A in my case which is enough to kill the battery. Removed tracker and all was good...
...until a year ago when battery would go flat after just a couple of days. New battery didn't fix it so I again spent time trying to track down any current drain. I was seeing just 80mA, and half this was my Toucan: but leaving the Toucan disconnected made no difference.
I have still not tracked it down - 40-80mA should not drain a battery after a few days so I think something randomly starts to draw excessive current after a while. Or it's something I missed.
For example, I do still have a Toad alarm installed, but disconnecting the siren (with it's back up battery) made no difference so it could be the Toad control unit itself, or the separate anti-hijack system. Or the sound system. These are all wired on their own in-line fuses (so bypass the usual fusebox, which is where I went through fuses one by one to try and track down excessive current drain).
I just haven't had the time to investigate further.
Too busy wiring up other people's cars lol.
Where are you located buddy I need some wiring done?
10 January 2016, 08:52 PM
#17
The thing about "smart" alternators is that they only charge the battery when they "think" it needs it: when there's a current being drawn. If the engine is not running the alternator is not charging, period: regardless of whether it is a smart alternator or not.
Portland, Dorset.
10 January 2016, 08:52 PM
#18
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Leaving the lights on overnight will drain the battery regardless of the alternator!
The engine has to be running, with the sidelights etc on for the "smart charging" system to work.
10 January 2016, 09:08 PM
#19
Yes I get the leaving them on overnight would drain the battery etc. But what im asking is with the ignition off and the lights or heater being switched to the on position means they are not actually on but the power is still draining minimally yes?
10 January 2016, 09:14 PM
#21
Ok thats what I thought! So I think you guys misunderstood me or I didnt quite explain it properly! 
So therefore I need to check the output then with a multimeter to see why Im having a sluggish start on cold mornings.
So therefore I need to check the output then with a multimeter to see why Im having a sluggish start on cold mornings.
Last edited by jonnyboy82; 10 January 2016 at 09:15 PM.
10 January 2016, 09:42 PM
#25
You get what you pay for - cheap ones tend to have leads that break, or a case that's brittle but will, nevertheless, do the job.
Maplin have a reasonable range and are, at least, easy to order/buy. I'm not recommended this as I haven't seen it but, superficially, it looks OK:
http://www.maplin.co.uk/p/precision-...ltimeter-gw18u
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