Battery's isolator - Saving radio settings

[Zcat7]

I use a battery isolator (on the earth terminal) to save my battery in the low use winter months and as an added level of security but it is a pain as I keep losing my radio settings. I read about "setting-saving" devices used by workshops to preserve radio lockouts, ECU fault codes etc during battery changes. They just plug a 12v source into the cigarette lighter and it's enough to preserve the low current demands of radio memory etc.

So here is where I need some advice from the more electrically knowledgeable among you. I was wondering how it would work if I fitted a pack of reachrgeable batteries across the radio's permanent live and earth with the intent being that it would charge up the pack when driving and discharge slowly when I've isolated the cranking battery. I know that it will ultimately provide current back to the permanent live circuit but so long as I don't try to draw any heavy current I would imagine the rechargeable would stand up OK?

Any faults in my plan?

1- Charge voltage/rate of the rechargeable batteries - would the alternator kill them?
2- would the courtesy light alone be enough to render them drained after a couple of minutes of opening the door?

 

[subheatadey]

Why not just use a trickle charge plugged in or use a solar panel charge plugged in then it keeps your battery at its optimum. :stonehim:

 

[Zcat7]

Because the battery will be disconnected...?

 

[Moseley]

You can buy a battery isolator with a low current fused bypass so it effectively keeps the electrics and any low current circuits live, but if someone tried to start it, the fuse would pop and everything becomes isolated.

Can’t help but think you’re making work for yourself by adding in a separate battery just for the radio settings, as this will need its own maintenance.


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[Zcat7]

That sounds like an option worth exploring. Any idea where I can get one? Thanks Moseley

 

[Moseley]

12 volt planet was where I got mine. Depending on the type of isolator you have, you may be able to retro fit an in-line fuse to yours as it is. It just needs some means of attaching a ring terminal either side of the main isolation switch.


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