Radio keep alive

[essexboy]

A little help please, I have a Kenwood car radio fitted to my boat , works well and has for a couple of years. The only niggle is that the only circuit alive when the master switches are off, is the bilge pump. So every time I go to the boat I have to reset the time and channels, it is getting to me.
Could I run the keep alive from a dry cell battery ?
How Long would it last ?
Would 9v be enough ?

Thanks in advance

 

[stelican]

What make of boat do you have,Could simply be a fuse disconnected.

 

[Plum]

A little help please, I have a Kenwood car radio fitted to my boat , works well and has for a couple of years. The only niggle is that the only circuit alive when the master switches are off, is the bilge pump. So every time I go to the boat I have to reset the time and channels, it is getting to me.
Could I run the keep alive from a dry cell battery ?
How Long would it last ?
Would 9v be enough ?

Thanks in advance

Check the installation wiring diagram for the radio. Most have a power supply wire plus a second power supply wire that's only purpose is to maintain power to the radio memory when the radio is turned off. If you can find this latter connection you could connect it to the bildge pump supply. This should then keep the radio memory alive yet ensure the radio is off when the master switch is off.

Www.solocoastalsailing.co.uk

 

[GrahamHR]

Yes, but use a 12v lead acid domestic alarm battery and a diode; wired so it is charged by the alternator when the engine is running.

 

[CharlieAlpha]

If you do have a 'memory power lead' for the radio [most do] that you in effect connect directly to the ships battery make sure it has an in-line fuse in the cable, the fuse rating will only need to be a few amps.

 

[essexboy]

Thanks for your replies, the alarm battery answer appeals to my wont cost a lot way of thinking !