Anybody know of any battery discharge protectors to go inline to an amp?

[Graham_A_M]

Hey guys. The amp I'm using is REALLY old, well before the days of the battery discharge protection. The amp will keep on draining the battery until its completely dead. Since I have my stock head unit, and this aftermarket amp I need to turn the amp on and off manually using a switch I have near the gear shift area in my drivers area.
Problem is I forgot to shut it off one day when heading into work, so I came back to a dead battery, which on my car is a quite a problem:nut:

So I was wondering: are there any "in line power cable" battery protectors that would shut off power to the amp if the voltage dropped too low, or one I can install to the remote at least to shut it off that way?

Or anybody know enough about electronic circuitry to design me one I can build myself and install?

Thanks a lot for reading this and offering any help you can.
-Cheers.

[mightymouseaveo]

personally when install amps with stock head units i use an accessory or ignition fed wire for the remote turn on, then there is no worries about leaving it on. what kind of vehicle do you drive i could find out what colour the wire is that you need to use to save your battery, would be alot easier

[revelations]

Just go to Canadian tire and get a 12v relay switch.

[Graham_A_M]

Originally posted by mightymouseaveo
personally when install amps with stock head units i use an accessory or ignition fed wire for the remote turn on, then there is no worries about leaving it on. what kind of vehicle do you drive i could find out what colour the wire is that you need to use to save your battery, would be alot easier

Its for my Z4. Yeah I tried doing just this, but I cannot find an "accessory-on" wire that I can do this with, and given the choice I'd rather not hack apart my stock wiring to any real degree. Sure if you have any suggestions that would be awesome, but I found none short of checking in the dash itself. Everything from behind the dash is a no-go.

Its a '04 z4, 3.0I with SMG tranny if that helps at all..

thanks a lot for the responses BTW.:thumbsup:

[mightymouseaveo]

im a certified installer and was always taught to go directly from the ignition switch. i have done this with all my installs and never once had a problem, use wiring coming from where the key is, you have 2 wires that you can choose from both will work exactly the same, one is green and one is purple. this will be the easiest way to do it, like i said, this is the way that i always install these. they will most likely be a little bit larger wire.

[5000Audi]

just run the remote into the fuse box, thats what ive done once, but if i run a switch make sure its one you can lite upso you can glance and see that its on

[jonny_q13]

accessory at the back of your stock head unit is purple white. the power antenna/ factory amp turn on wire is white. if u use a multi meter to test at the back of ur head unit that will be all u need. the other option is to use either green or purple at ur ignition harness as both are ignitions that cycle with the key and depending upon location and how easy panels or the radio are to remove u have more than one option.

[97'Scort]

Originally posted by mightymouseaveo
im a certified installer and was always taught to go directly from the ignition switch. i have done this with all my installs and never once had a problem, use wiring coming from where the key is, you have 2 wires that you can choose from both will work exactly the same, one is green and one is purple. this will be the easiest way to do it, like i said, this is the way that i always install these. they will most likely be a little bit larger wire.
The only time you screw with ignition wiring is for alarms. There are TONS of switched wires floating around before you should make a mad dash for the steering column.

Jonny boy there has it right, although I'm not 100% on the turn on wire for an '04. Ask over at Bimmerforums.com, then hook into that one.

[mightymouseaveo]

that is your opinion, mecp certification training states otherwise but obviously you are smarter than me.

[97'Scort]

I'm just curious why you would bother hooking straight to the ignition wiring when there's a perfectly good factory amp turn on wire right there for your pleasure? Seems like a complete waste of time and the customer's money, since it's going to take longer to get into the dash on top of everything else.

[mightymouseaveo]

because most newer vehicles have remote turn on via data line, its a general rule of practice, and also applying an electrical load on a larger gauge wire like an ignition wire is less likely to cause problems than hooking onto a smaller wire elsewhere. and you dont have to take the whole dash apart to get to ignition wires, most radios require removing as much if not more than that.

[97'Scort]

While I do agree with a lot of that, BMWs have a relatively large gauge wire for their amp wire, and it's conveniently located under the side panel in the trunk. Amp turn on circuits are under virtually zero load and therefore do not need to be able to handle current over 1A anyways. All he has to do is tie a relay into that turn on wire and away you go.

In this case, it's an opportunity to use a much cleaner and simpler install. Part of doing audio installs is to know the proper way to do things, which is what you are doing, and expanding on that knowledge on a per-case basis for the customer.

If I did all my engineering work exactly by the book rather than looking at the individual case carefully, I may not spot a new material or design flaw that needed fixing.

[Grogador]

I had to use a relay, since I go away for 1 or 2 weeks sometimes and my two 1F caps would drain the battery if the weather was cold (hot? varied? can't recall). I used the 'remote' wire off the deck, through the firewall and to a relay near the battery/fuse.

Footnote: yes I know there's probably a switched source under the hood, or even closer to the firewall in the dash I could've used, but I like the idea of cutting power to amps/caps when the deck is turned off, as opposed to the ignition. Easier than searching and splicing anyway :)


Originally posted by Graham_A_M
The amp I'm using is REALLY old,

Might be leaky and need one too...