Batteries for a simple horn circuit.

[Polywobblydriver]

My question is 'What battery do I use'? I am trying to to build a simple horn circuit for my wife's mobility scooter. My idea is to use a 6 or 12 volt motorbike horn, a battery and a switch in a simple circuit. I want something that is completely separate so it can be swapped between scooters. I do NOT want to mess with the existing wiring harness on the scooter. I don't understand all this 'Amps per Hour' stuff so I don't know what would be the smallest battery (in physical size) I could use. Could I get away with regular AA, C or D cell batteries?

 

[DPG]

My question is 'What battery do I use'? I am trying to to build a simple horn circuit for my wife's mobility scooter. My idea is to use a 6 or 12 volt motorbike horn, a battery and a switch in a simple circuit. I want something that is completely separate so it can be swapped between scooters. I do NOT want to mess with the existing wiring harness on the scooter. I don't understand all this 'Amps per Hour' stuff so I don't know what would be the smallest battery (in physical size) I could use. Could I get away with regular AA, C or D cell batteries?

Although bike/car horns take a fairly high current, they are only taking this for the few seconds the horn is operating. So you need a battery with a reasonably high short term current output (a PP3 would be no good), but you don't need a particularly high Amp-hour figure.

I'd suggest a small 12V SLA (sealed lead acid) battery would be ideal for this application.

Obviously it was need charging at some point, but you would be looking at months before this was necessary.

Remember to use a fuse immediately after the connection to battery positive.

 

[Polywobblydriver]

Although bike/car horns take a fairly high current, they are only taking this for the few seconds the horn is operating. So you need a battery with a reasonably high short term current output (a PP3 would be no good), but you don't need a particularly high Amp-hour figure.

I'd suggest a small 12V SLA (sealed lead acid) battery would be ideal for this application.

Obviously it was need charging at some point, but you would be looking at months before this was necessary.

Remember to use a fuse immediately after the connection to battery positive.

Thank you for your help. By SLA battery do you mean the small 'brick' batteries you get in cars and motorbikes? What sort of Ah rating does it need to have and what A rating would you suggest for the fuse? I'm trying to keep the whole thing as small as possible as it is to go onto a mobility scooter that dismantles to fit into the back of my car.

 

[brianmoooore]

Makes a big difference with the type of horn you intend to use. A 'normal' electromagnetic car type horn uses a much higher current (and inrush) than an electronic one.

 

[telectrix]

small electronic siren as you get for a burglar alarm or even with a cheap car alarm system. power with a 1.2AH SLA battery (also used with burgar alarms). pesrsonally, I'd use the scooter battery as a power source. a couple of piggy back terminals to connect.

then again could always go halfords and buy a bicycle bell. ??

 

[Polywobblydriver]

small electronic siren as you get for a burglar alarm or even with a cheap car alarm system. power with a 1.2AH SLA battery (also used with burgar alarms). pesrsonally, I'd use the scooter battery as a power source. a couple of piggy back terminals to connect.

then again could always go halfords and buy a bicycle bell. ??

I appreciate the suggestions ?? Sadly, I've tried the bicycle bell and bulb horn methods and mobility issues ruled them out. Alarm sirens are also no good as they are too high pitched for the job I need it to do.
Ideally it needs to be a push button setup using a deep note horn from a bike or a car. Piggybacking is no good either as the scooter needs to come apart to fit in the car hence the 'Stand Alone' system I'm trying to build.
So basically I need to figure out the Ah rating I need to power a motorcycle/car horn, (either 6 or 12 volt), and the amp rating for the fuse I'll need in the circuit.

 

[DPG]

I would say a 12V 3Ahr battery would be easily sufficient. Fuse rating approximately 10A.

Try it first before installing, but should be fine with that. Obviously you need a push button switch with a roughly 10 Amp rating also, and suitable wire.

 

[Polywobblydriver]

I would say a 12V 3Ahr battery would be easily sufficient. Fuse rating approximately 10A.

Try it first before installing, but should be fine with that. Obviously you need a push button switch with a roughly 10 Amp rating also, and suitable wire.

That's loads of help. Thank you! I'll have a look at some switches. Was thinking of trying to rig some sort of Foot button. Could you suggest anything?

 

[DPG]

That's loads of help. Thank you! I'll have a look at some switches. Was thinking of trying to rig some sort of Foot button. Could you suggest anything?

There are foot switches available, have a look on Ebay etc. May need to be weatherproof though, and make sure it has enough current carrying capacity.

 

[Polywobblydriver]

There are foot switches available, have a look on Ebay etc. May need to be weatherproof though, and make sure it has enough current carrying capacity.

Thanks again! 10 Amp switch rating. Would standard speaker wire be good enough or would i need to go up a size?

 

[DPG]

Thanks again! 10 Amp switch rating. Would standard speaker wire be good enough or would i need to go up a size?

Thicker. The sort of wire you would traditionally find on car electrics.

 

[Polywobblydriver]

Thicker. The sort of wire you would traditionally find on car electrics.

I'll go up two or three sizes above speaker thickness that should do it. Cheers for the help DPG!