spunky
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 posted on 6/7/04 at 09:21 PM |
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How much current do rad fans draw.
Hi all, been out to Lincoln VRO toay for final inspection and registration.
It's been damn hot here resulting in both my cooling fans running most of the time.
When I pull in for juice (which is very often) the car is reluctant to start and a couple of times I've had to produce jump leads and beg a euro
box driver for assistance (NOT  !)
Is it possible that both fans are pulling more power than the alternator is supplying? No rating on the motors, one is from a Blade the other from a
Blackbird.
On a similar theme, there was an interesting discussion on batteries, which I can't find now. I only have a bike battery and not easy to fit a
car battery. What are my options. IIRC there were 'super' batteries available, unfortunately can't recall who posted the info.
Thanks
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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Hellfire
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| posted on 6/7/04 at 09:29 PM |
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I think Demon Tw**ks sell high power batteries IIRC
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mangogrooveworkshop
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| posted on 6/7/04 at 10:03 PM |
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Subject: Battery and altenator
www.odysseybatteries.co.uk small high power batts telephone 01832 275808 enersys ltd
www.racemettleltd.co.uk alt and starters
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Hasse
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| posted on 7/7/04 at 06:42 AM |
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In my opinion, the two fan motors are not likely to use all the alternator current.
When you have problem starting, are you able to crank for some time, (a total of > 1 minute or so), or do you run out of charge very quickly?
Maybe you should test how much current your alternator supplies with a "clip on" amp meter?
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Peteff
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| posted on 7/7/04 at 08:57 AM |
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Carry one of these about.
http://www.machinemart.co.uk/product.asp?p=010310400
It will help till you get the problem sorted and will come in useful for other stuff after. Keep it charged and it lasts ages. I've had one for
6 years and it powers soldering irons and is used as a camping battery. They do one with a tyre inflator for more money as well. Various places do
them at a lower price but this was easiest to find.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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spunky
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| posted on 7/7/04 at 09:01 AM |
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I'll get the meter out today and do some testing.
My other thought (thats two in a week ) was could it be temp. related. they bay gets very hot including the battery!
Mango- thanks for the links. The spec on the Odyssey batteries seems very good, bit pricey though. any experience of using them?
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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Jimbo
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| posted on 7/7/04 at 05:50 PM |
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Check here I have my fan wired up as this shows, and is fine.
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spunky
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| posted on 7/7/04 at 10:33 PM |
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Ok. did a bit of poking about with my meter today.
With both fans running the current draw is 8.5A (car stationary) so thats around 100W. shouldn't be a problem for the alt.
Battery shows 12.8V not running and 14.2 at idle, dropping to 13.6 with fans running, so ok there.
So I tried my other theory and insulated the battery and when for a blast  and so far so good.
My knowledge of batteries is old and hazy but the science may be something like.....
Impedence of cell determines the amount of charge that the cell can release in a high load pulse. Impedence increases with temp, thus hot battery
can't give the starter the uuumph required to crank the engine. Of course I could be talking bollox
Pete, I have a power pack with all the bells and whistles but don't have the luxury of a boot like you se7en drivers. My boot's full of
engine
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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NS Dev
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| posted on 7/7/04 at 11:22 PM |
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that theory might hold water? just as an aside though, different fans do draw very different currents, I was somwhat shocked when the Vauxhall Senator
electric fan I used in my old 16v Manta kept blowing 25amp fuses.......until I found it draws 26amps and Vauxhall use a 30amp fuse for it!!....doh!
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spunky
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| posted on 8/7/04 at 12:28 AM |
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quote:
Originally posted by NS Dev
that theory might hold water? just as an aside though, different fans do draw very different currents, I was somwhat shocked when the Vauxhall Senator
electric fan I used in my old 16v Manta kept blowing 25amp fuses.......until I found it draws 26amps and Vauxhall use a 30amp fuse for it!!....doh!
Must admit I was surprised the loading on the fans was only 8A, but they are 'flat motor' bike units and on a bike are only required when
the bike is stationary.
Also my installation is hardly ideal and would expect the current drain to increase with the heat and turbulance.
Fingers crossed, the battery insulation will do the trick
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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spunky
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| posted on 13/7/04 at 09:19 AM |
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Just as a follow up on this thread.
Insulating the battery appears to have been successful, haven't had a 'failure to start' since.
Now looking to improve the cooling system.
Who has used the Red Line water wetter and was there a noticeable improvement in cooling efficiency?
Any other thoughts on cooling, apparently the SP1's were designed to run at 106 degs.
John
The reckless man may not live as long......
But the cautious man does not live at all.....
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