Hi there, these might seem like dumb questions but I'm afraid I'd rather look stupid on here than start fiddling with things that might go bang on the bus. The first one's about my stereo. Is it possible for an amp/speaker setup to drain a standard battery faster than the dynamo can charge it? I'm wondering cos the 600W amp, two 100W speakers and 225W sub under the bed are disconnected from the power at the mo. The PO didn't mention why but I did some sums that suggest it'll draw most of the juice from the battery very quickly. Obviously, it wouldn't be working at full blast, but even still, could this be why it's sitting there just looking ugly or have I got totally the wrong end of the stick? Presuming I'm not completely wrong, would fitting a leisure battery and running the sound system off that solve the problem, or would it just transfer the problem from the main battery to the secondary one? And would fitting a big alternator help, or am I again missing the point entirely? I know there are a load of threads on leisure batteries but, to be honest, the more I read of them the more confused I get. Apologies if these are idiotic or nonsensical questions, the last time I studied physics was about 18 years ago so my understanding of electrics is a bit sketchy.
No such thing as a stupid question dude if you dont ask you dont learn A sound system like that will drain the main battery faster than a dynamo will charge it Im fitting a large amp into mine eventually and plan on running it of a leisure battery and fitting a larger output alternator and split charge relay
Cheers for the info, looks like an alternator conversion will be getting added to the shopping list. Not even driven the bus more than 20 miles and already I've spent thousands of imaginary pounds. Not that I need a whacking big stereo, just be nice for folks in the back to be able to hear the choons.
I don't really see how this will happen if the battery is good. Plenty of people have subs and amps in beetles and buses with a std dynamo
600 watts is a lot, isnt the standard alternator 55 amps? what size fuse does it have? I'd imagine that it wont be outputting 600 watts at normal volume levels without causing ear damage. best thing to do is to stick a multimeter on it and measure the draw at different volume levels. alternatively you could measure the battery voltage before starting the engine then go on a reasonable run with the stereo on then measure the battery voltage again a few minutes after turning the engine off and see if its higher or lower a full battery should be about 12.5 or 12.6 volts. You could do this with the lights on too to see if lights plus stereo is too much for your alternator/dynamo. you should also test for draining when everything is off
Thanks for the replies guys. As Scote says, the amp wouldn't be running at full chat but I was worried that should I have that plus lights/wipers/anything else on at the same time it might prove too much. I'll get the missus to "borrow" a multimeter from her work and do some testing. Ta for the tip. It's a stock 1600 dynamo as far as I'm aware and I've a horrible feeling that makes it 38A. One the bright side, the battery's less than a year old and looks in good nick Not sure of its specs though cos I'm at work and the bus isn't. Same goes for the fuse. From memory, it's in-line, red and it looked pretty "maxi" sized, so guessing from a quick online browse that it's a 50A.
put a lesiure battery in even if it dosent get fully recharged at least you wont kill the main battery. and you can always charge it from the mains or solar before a trip.
obviously running the amp from a leisure battery will be best as you can have the stereo on when the vans is parked, the amp will only draw alot of current when at higher levels ps the 600w rating is total bs made up to sell amps to chavs, saying that if your driving round with the lights and wipers on and the stereo on loud the dynamo will only just keep up so a alternator upgrage would help saying that a decent battery and just driving the van during the day in the summer a dynamo will probably be ok?
