connecting regulated 12v DC to an e30

[argon]

Hi just wondering if it's a good idea to connect a regulated 12v DC supply in parallel to my batteries when using car accessories while engine is off?

reason im asking is i listen a lot music from my car when im working in my garage. i have 6 speakers installed and 2 subwoofers so battery will just last for about an hour if i continuously blast music with the engine off. im thinking if i can somehow tap power from my AC home supply then i dont have to worry about my battery draining.

to all electronic gurus here i want to get your input on this. will this work or idea is just plain stupid? thanks

[Das Delfin]

You can get a Shumacher combination battery maintainer/charger which has a nice 3 amp maintain setting and use that to keep your battery charged.. it's a little more complicated than just a power supply

[nando]

you can get a battery tender from Costco for like $30 as well. would be enough to power the stereo I'm sure.

I just saw you're from Auckland. Assuming that's in NZ, well, Costco won't help - but you can find stuff like that online. :)

[george graves]

IIRC you can put about 14v onto a lead acid with out it complaining too much. Much more and you start to muck up the acid. Battery "tenders" are usually really low amperage devices that won't keep up with the current draw at all.

No real easy solution of what you want to do that I know of. Other then using something like a 10A battery charger, and even that won't keep up with sub-woofers. Plus, car audio sounds like poop outside of the car.

I picked up some decent speakers and an amp that is my garage audio fix. Will be adding a small sub that I'll retire from home audio duty, and put in the shop. Works wonderfully when combined with an old android phone or table to listen to music. No contract needed, just wi-fi your favorite app.

Music in the "shop" is a must have - it makes working on stuff so much more pleasurable, and the time flys by.