Results 1 to 11 of 11

Thread: Inline battery backup setup for head unit?

  1. #1
    Bannered takai's Avatar
    Join Date
    Dec 2002
    Location
    Melbourne
    Posts
    11,273

    Inline battery backup setup for head unit?

    Currently I drive the MX5 rarely enough that i end up sometimes flattening the battery between drives. Usually though it just drops the battery voltage on cranking and needs to be jump started. However, this drop of battery voltage is enough to clear the settings on the head unit, and resetting it all is a pain as it requires repairing with bluetooth etc.

    Has anyone come across a simple setup that would keep the headunit from resetting if the battery fully drains? Thinking perhaps like a small inline battery or something.
    Chris
    ------
    The new nugget
    I never saw a wild thing sorry for itself. A small bird will drop frozen dead from a bough without ever having felt sorry for itself. - D.H.Lawrence

  2. #2
    Opens
    Join Date
    Jan 2002
    Location
    Brisbane, QLD
    Posts
    9,618
    lol fuck dude, find something else to worry about.

  3. #3
    Registered User GreatWallGT500's Avatar
    Join Date
    Dec 2012
    Location
    melbourne
    Posts
    901
    Trickle charger

    Sent from my SM-G610Y using Tapatalk

  4. #4
    Bannered takai's Avatar
    Join Date
    Dec 2002
    Location
    Melbourne
    Posts
    11,273
    Quote Originally Posted by tim510 View Post
    lol fuck dude, find something else to worry about.
    Lol, its pretty minor. But damned if the Kenwood in the car isnt the worst to re-setup every time. Mainly hoping that there is something off the shelf i can wire in to the power feed. I would think that various camper and other requirements might be good for it, but evidently not. Plus google just turns up pages of "audiophile" stuff on using eleventy billion stage UPSs for their spike mounted hand wound transformer amplifiers.

    Quote Originally Posted by GreatWallGT500 View Post
    Trickle charger

    Sent from my SM-G610Y using Tapatalk
    Yeah, its normally on trickle charger... until i unplug it to do something else and forget. But the Ctek basically lives in the boot.
    Last edited by takai; 15-04-19 at 02:18 PM.
    Chris
    ------
    The new nugget
    I never saw a wild thing sorry for itself. A small bird will drop frozen dead from a bough without ever having felt sorry for itself. - D.H.Lawrence

  5. #5
    Registered User
    Join Date
    Nov 2017
    Location
    Brisbane
    Posts
    142
    Something similar exists... I can recall maybe 15 years ago now, a Battery World bloke clipping a small device to the battery leads during a battery swapover in a car, so the radio/clock/etc didn't require resetting. I don't know how much capacity it'd have as it was pretty small, but then again the power requirement would also be small. Might be worth a phone call to them, anyway?

  6. #6
    No I'm Not Shonky Shonky's Avatar
    Join Date
    Nov 2001
    Location
    Brisbane
    Posts
    5,438
    The clip on things during a battery change over might be OK, but the general problem there is that it will discharge into the main battery particularly as it goes flat.

    Some sort of small 12V SLA battery with a diode in line in the memory/always on supply line to stop it feeding back to the main battery might do what you want. Battery then charges off the car when running too. Diode needs to be rated high enough to power the head unit as the always on line is usually where they draw their power.

    I think it could definitely could be as simple as a 12V rechargeable battery and a single diode.

    Wouldn't it just be better to not run the main battery flat though like with your Ctek? Plus you don't kill your battery as easily?

  7. #7
    Bannered takai's Avatar
    Join Date
    Dec 2002
    Location
    Melbourne
    Posts
    11,273
    Quote Originally Posted by Shonky View Post
    Wouldn't it just be better to not run the main battery flat though like with your Ctek? Plus you don't kill your battery as easily?
    Lol, it would be better... if i could remember it more often.

    Apparently marine stereos have a battery backup system in them, so perhaps that is an option.

    I dont understand why they dont just chuck a CR2032 or something button cell into the unit for the basic memory that these units have. Cant see it taking much more power draw than a bios battery.
    Last edited by takai; 15-04-19 at 04:40 PM.
    Chris
    ------
    The new nugget
    I never saw a wild thing sorry for itself. A small bird will drop frozen dead from a bough without ever having felt sorry for itself. - D.H.Lawrence

  8. #8
    BLING BLING PLAYA's Avatar
    Join Date
    Mar 2002
    Location
    adelaide
    Posts
    6,395
    Just stop the battery discharging so you don't fuck something of value.
    3D scanning
    3D modelling
    Structural certification
    3 and 5 axis milling

  9. #9
    Bannered takai's Avatar
    Join Date
    Dec 2002
    Location
    Melbourne
    Posts
    11,273
    Quote Originally Posted by PLAYA View Post
    Just stop the battery discharging so you don't fuck something of value.
    The only thing i can figure out discharging the battery is the car alarm, which i kind of dont want to disable...
    Chris
    ------
    The new nugget
    I never saw a wild thing sorry for itself. A small bird will drop frozen dead from a bough without ever having felt sorry for itself. - D.H.Lawrence

  10. #10
    *Italian Stallion* milo's Avatar
    Join Date
    Feb 2003
    Location
    Stuck in a Lift....... In Wollongong!
    Posts
    1,442
    What about something like THIS?

    I know my Auto Electrician Cousin uses something similar when working on Customers Cars, so they don't lose Radio Presets..
    1969 Datsun 1000 Sedan
    1989 1.6l Daihatsu Charade

    Life For me Has it's UP'S and DOWN'S........ I fix ELEVATORS

  11. #11
    No I'm Not Shonky Shonky's Avatar
    Join Date
    Nov 2001
    Location
    Brisbane
    Posts
    5,438
    They are good for when the main battery is disconnected. When the main battery remains connected but runs down below the voltage of the backup battery, it will run the backup battery flat quickly.

    Also those things frequently don't work on modern cars as they're a bit more complicated than relays and switches.
    Last edited by Shonky; 16-04-19 at 07:22 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •