Electronics, Lighting, & Gadgets - Auto or motorcycle horn current draw

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KLW2
09-17-07, 10:22 AM
Does anyone know what the typical current draw of a car or motorcycle horn is? I'm building a DIY light system using a 12v SLA 7amp battery and wonder if a horn might not fit in my plans as well...:rolleyes:
Thanks

seeker333
09-17-07, 02:13 PM
I don't know, but they can't pull much and it's used very little, compared to light.

I expect its effect on battery life is insignificant.
Photosmith
09-17-07, 08:28 PM
Their website doesn't appear to permit direct linking, but Hella's Supertone horn, part number 003399051, is listed as 78 watts, which at 12v is only a 6.5 amp draw. That would squeeze in just under your 7amp battery's specified limits Of course, fact is, you can usually draw 2x of a battery's rated amperage in short bursts, but still, it is good to stay within it's rated range. That horn is a healthy 116db, which is probably plenty loud for scaring the crap out of iPod joggers on a MUP.

KLW2
09-18-07, 05:40 AM
Their website doesn't appear to permit direct linking, but Hella's Supertone horn, part number 003399051, is listed as 78 watts, which at 12v is only a 6.5 amp draw. That would squeeze in just under your 7amp battery's specified limits Of course, fact is, you can usually draw 2x of a battery's rated amperage in short bursts, but still, it is good to stay within it's rated range. That horn is a healthy 116db, which is probably plenty loud for scaring the crap out of iPod joggers on a MUP.

Thanks Photosmith!
Map tester
09-18-07, 09:52 AM
I have been using a standard car replacement horn from the auto store for years and had no problems. My battery now is a 3.6 Ah SLA (3 lbs), down from a 7 Ah (6.15 lbs), then to a 5.5 Ah SLA (4.33 lbs) (went all LED lights). The horn comes in very handy, especially when people are backing out and not looking carefully! I use a car replacement horn button inside a section of old inner tube for wet weather protection.
KLW2
09-18-07, 06:43 PM
I have been using a standard car replacement horn from the auto store for years and had no problems. My battery now is a 3.6 Ah SLA (3 lbs), down from a 7 Ah (6.15 lbs), then to a 5.5 Ah SLA (4.33 lbs) (went all LED lights). The horn comes in very handy, especially when people are backing out and not looking carefully! I use a car replacement horn button inside a section of old inner tube for wet weather protection.

Map tester,
Have you been using a Relay with the switch or just battery, switch, horn in series?
Keith