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the big 3

Posted: Tue Nov 25, 2008 12:28 pm
by meek.tv
ive been advised on the talkaudio forum to upgrade what they call the BIG THREE which consists of upgrading the wiring (to 4awg or 0awg) on:

1.The alternator to battery main power cable
2.The alternator to chassis earth cable
3.The battery to chassis earth cable

now i think 2 and 3 should be easy enough but im a bit more worried about hte alternator to battery connection due to the distance from one to the other. i havent had a proper look under the seat but does anyone forsee any problems?
thanks

Re: the big 3

Posted: Tue Nov 25, 2008 12:35 pm
by g8dhe
I haven't checked mine in detail but I would have guessed that the Alternator to Battery cable is easily 5mm in diameter as fitted if not thicker and AWG4 is 5.2mm. What size do you have currently ?

Edit - Ah ok let me just fit my ear defenders on my head .. THAT'S BETTER, IF YOUR GOING TO BE DRAWING THAT SORT OF POWER LEVEL YOU WOULD BE BETTER OFF WITH A SECOND BATTERY, THEN YOU CAN USE awg 0000 AT LEAST. SERIOUSLY YOU NEED TO KNOW WHAT THE ACTUAL CURRENT PEAKS WILL BE TO MAKE A SENSIBLE CHOICE OF CABLE, THE POWER RATINGS OF THOSE AMP'S HAVE LITTLE TO DO WITH REALITY - THERE MARKETING WORDS ONLY !

Re: the big 3

Posted: Tue Nov 25, 2008 1:07 pm
by meek.tv
i havent upgraded any of it yet, so its as standard. will try an have a peak when i get a chance.
at the moment i have 4gauge power going to the amps but i think when the new ones arrive i will have to upgrade to 0gauge and i think i need to do the "big three" to match

Re: the big 3

Posted: Tue Nov 25, 2008 7:42 pm
by dandywarhol
Why are you wanting to do this? :?

Re: the big 3

Posted: Tue Nov 25, 2008 9:59 pm
by g8dhe
dandywarhol wrote:Why are you wanting to do this? :?
Take a look for the talkaudio forum, and search for his posts there, then you will understand my edit in my first reply :P

Re: the big 3

Posted: Tue Nov 25, 2008 10:05 pm
by meek.tv
my new amps (when they arrive) will be pulling about 900wrms so "the big three" upgrade is meant to help minimise voltage drop with somethign similar to this
http://www.caraudiodirect.co.uk/dynamic ... 064bt4mec0
im no expert on the matter ive just been reading up on it a bit on the talkaudio forum and it seems to be a tried and tested aid to help the charging side of things
searched here for tb3 and theres a lot of posts but generally it says its worth doing http://www.talkaudio.co.uk/vbb/search.p ... id=4675467 seems to help with lights dimming under load etc

oops didnt read the EDIT and your last post g8dhe

ive been advised to use 0awg for the power and the "big three" so i guess ill give it a go and see how it goes :S

Re: the big 3

Posted: Tue Nov 25, 2008 10:23 pm
by madmile
Did you tell them it was for a 2.5 TD engine, not a 1.0l corsa or saxo :lol: .
Only joking - I know nothing about car audio and cant fathom the amounts people spend on it - but each to thier own.

Re: the big 3

Posted: Tue Nov 25, 2008 11:03 pm
by dandywarhol
g8dhe wrote:
dandywarhol wrote:Why are you wanting to do this? :?
Take a look for the talkaudio forum, and search for his posts there, then you will understand my edit in my first reply :P
Gocha :D What do you use to gather up the blood from your eardrums?

Re: the big 3

Posted: Tue Nov 25, 2008 11:23 pm
by crazy uncle gray g
:shock: I think I`ll go back to the campsites thread, I didn`t realise you all spoke Japanese on the Techie one #-o

Re: the big 3

Posted: Wed Nov 26, 2008 12:54 am
by g8dhe
meek.tv wrote:my new amps (when they arrive) will be pulling about 900wrms so
Humm, well lets loose the RMS from the Watts as it doesn't mean much to start with,
then lets make a wild assumption for ease of the numbers that your amplifiers are 90% efficient so your amplifier will be drawing 1000Watts that's 1Kw from your supply
or 83.3Amps (and that's a conservative figure!).
Lets turn that into Horsepower as generally that's how you would measure engine power 746Watts=1HP so that's about 1.3HP,
how much power does a 2.5L V6 engine develop about 200HP I think (Mazda MVP is rated at that)
so you might actually feel the music affecting the pull of your vehicle :mrgreen: [-o< [-o< [-o<

Actually if you pull any really significant current directly from the alternator to the amplifier your likely to here alternator "whine" (a nasty high pitched whistle) as well, your aim should be for the battery to supply something like 80%-90% of the load, the alternator will then recharge the battery between the drum beats :P :P

Re: the big 3

Posted: Wed Nov 26, 2008 11:31 am
by meek.tv
g8dhe wrote:
meek.tv wrote:my new amps (when they arrive) will be pulling about 900wrms so
Humm, well lets loose the RMS from the Watts as it doesn't mean much to start with,
then lets make a wild assumption for ease of the numbers that your amplifiers are 90% efficient so your amplifier will be drawing 1000Watts that's 1Kw from your supply
or 83.3Amps (and that's a conservative figure!).
Lets turn that into Horsepower as generally that's how you would measure engine power 746Watts=1HP so that's about 1.3HP,
how much power does a 2.5L V6 engine develop about 200HP I think (Mazda MVP is rated at that)
so you might actually feel the music affecting the pull of your vehicle :mrgreen: [-o< [-o< [-o<

Actually if you pull any really significant current directly from the alternator to the amplifier your likely to here alternator "whine" (a nasty high pitched whistle) as well, your aim should be for the battery to supply something like 80%-90% of the load, the alternator will then recharge the battery between the drum beats :P :P
the amps have 2x30A fuses in one and 2x25A fuses in the other so ami right in guessing that max draw would be 110A?
if i did go down the second battery route would it be better to simply wire them both in parrelel to each other or to use a split charge system like the ones wilton sells on ebay?


whats the cheapest place for second battery trays/batterys
why do these jobs always end up costing more than you first think?

Re: the big 3

Posted: Wed Nov 26, 2008 11:37 am
by meek.tv
http://www.dailymail.co.uk/news/worldne ... -hour.html

ill try not to get myself a barry sentence :lol:

Re: the big 3

Posted: Wed Nov 26, 2008 12:57 pm
by g8dhe
meek.tv wrote:ill try not to get myself a barry sentence :lol:
Love it ! (The idea at least :P ) I wouldn't actually appreciate the sentence either :cry:
meek.tv wrote:the amps have 2x30A fuses in one and 2x25A fuses in the other so am i right in guessing that max draw would be 110A?
Yup (well sort of, assuming each fuse does take half the current each, might not be the case in reality) the fuses will blow at 110A and that sort of rating would make sense for the total power level as well.

I wouldn't even consider using the starter battery myself (my radio gear is cabled direct back to the L/B and separately fused from the Zig unit) for that sort of load and device, if you ever get a chance to see the sort of voltage surges and spikes that occur on vehicle engine supplies you wouldn't want to either! Surges up to 60-80 Volts can be expected under some conditions and even higher for very short spikes. Unless the device is specifically designed to run from normal vehicle wiring then your asking for trouble. Having said all that, with careful planning and cabling directly back to the battery and its own fuses the worst of the problems can be avoided, and in many cases the worst won't be seen anyway - but if your going to couple several hundred quids worth of equipment in to the van then for the sake of a few extra pounds and possibly an hour or two adding the wiring (some times the more painful bit) it makes an awfull lot of sense :!:

If you do use a L/B (most sensible) then I would go for the Willington kit, they do the battery tray as well I think :?: if not then a search on the forum will identify a supplier :idea:
meek.tv wrote:why do these jobs always end up costing more than you first think?
Yup, always happens. Always amused when you see an estimate for a large project and people saying that it musn't/won't cost more / run longer than the estimate - what do they think an ESTIMATE is :!:

Re: the big 3

Posted: Wed Nov 26, 2008 2:59 pm
by meek.tv
g8dhe wrote:
If you do use a L/B (most sensible) then I would go for the Willington kit, they do the battery tray as well I think :?: if not then a search on the forum will identify a supplier :idea:

how do these work?
does the alternator connect to both batteries to recharge them?

its probably worth doing. its been on the wish list for some time
whats the biggest battery that wil fit under there? im assuming these also are not cheap :'(
might be worth trying a breakers to see if they have a bongo with a battery tray, maybe a second hand split charge set up would be a bit sketchy :S

Re: the big 3

Posted: Wed Nov 26, 2008 5:28 pm
by mikexgough
I got a Willinton kit with tray for £105 and a 110ah Leisure battery for £60, snug fit but it goes in.
The kit to fit is easy peasy with little diy experience but if you are fairly good it's no probs at all, very straight forward and is the dogs gonads IMHO.
Halfrauds want £139.99 for a 110ah LB in town here........I thought Dick Turpin was hanged way back......