Monday, February 27, 2006 - 11:31 am, by: Paul Bernasconi(Pauli)
i've been thinking a bit about what i'm going 2 do as far as my ICE system goes. at the moment i have a system in mind that involves a double din unit aswell as a dvd stacker and 2 amps.
my though is its going 2 drain a lot of power and am curious if this will require another battery.
has anyone here had any problem with power drain and if so what was your resolution.
Monday, February 27, 2006 - 11:38 am, by: Avin Luther(Lex_luther)
Soarers have big batteries. the accessories wont drain much, it depends what speakers you are using. If you put in big subs that are tuned down low it will draw a bit, just add a capacitor to even out the supply to the amps for when the big bass hits.
Monday, February 27, 2006 - 05:12 pm, by: Jason Kingsmill(Jason_k)
If you're adding another abttery in the boot, then you must use a sealed type battery.
Avin, yeah mate, obviosuly more effort on the Alternators part.
You can get a switched battery system (the same as a lot of 4WD's use). They allow the primary battery to charge, then when the primary battery is at a predetermined charge level(normally 13.2V max), it will switch in the second battery to charge. Problem is, you need a decent battery isolator with a good noise filter with most EFI cars, as switching the large amount of current that they do, generates some pretty high voltage transients that could damage components/cause pops and so forth in audio.
I don't know how effective isolated batteries would be with an audio system though. It might be easier to just run the batteries in parallel.
Monday, February 27, 2006 - 06:03 pm, by: Mark Paddick(Sparks)
Less effort from the alternator, probably, overall. (think about it Jason ). If you have big enough power amps to require the addition of a capacitor or battery then the fact that a battery is up the back near the amplifiers will in fact REDUCE the current drawn by the amps. The overall alternator power requirement stays the same regardless off the number of batteries, except for a very small amount required to 'float' the second battery....negligeable in this context. It is the load current that determines the load on the alternator (obvious ). In a really large sound system setup the second battery will result in a reduction in alternator load because the resistive wiring losses from amps to battery are much smaller and instantaneous peaks in load current are now averaged out by the huge capacitance of the second battery, as are peaks in charge current.
A battery has much more capacitance than any capacitor yet built.
The second battery is taking load off the main battery, the alternator load doesn't change, except as menioned above it will actually be smaller, it is merely split between two batteries
Monday, February 27, 2006 - 06:34 pm, by: Mark Paddick(Sparks)
Yes, the natural assumption is that adding as second battery will increase the load on the alternator. This is not necessarily the case and if the second battery is sited in the right place a reduction of alternator load is more often the case. The only time when the alternator will be expected to supply a significantly incresed current is if BOTH batteries are heavily discharged. This can be overcome with simple preventative measures ranging from a couple of power diodes to intelligent charge regulating systems.
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