12v battery hookup

[Soloratov]

Probably a simple question, but figure I should ask. I have a circuit that is running off 12v. The plan is to run it off a car battery. My question is this, the circuit is 12v, pulling roughly 120mA, whats the risk of frying the circuit? And, should I put a fuse inline?

 

[blueroomelectronics]

Your car is unregulated and can be as high as 15V, what are you connecting?

 

[Soloratov]

it's actually a golf cart. The circuit is a 12v on-off relay/motor setup.

 

[nsklavos]

A 1/4 amp inline fuse wouldn't hurt, just to be safe. If you are using the battery that is not installed in a vehicle, the voltage may be higher than 12v when fully charged.

 

[Soloratov]

Ok, I will add the fuse. Seemed to be a good idea. Not to worried if the voltage goes a bit over 12v, the parts I chose are rated for it...main reason I chose them. Was more worried about the amps behind the battery, but I think I understand that a circuit will only pull what it needs, and wont get "pushed" by them. Is that correct...not sure how to say it but I know what I mean.

 

[blueroomelectronics]

Yep, fuse is a good idea and your circuit will only draw what it needs.

 

[Reloadron]

Ok, I will add the fuse. Seemed to be a good idea. Not to worried if the voltage goes a bit over 12v, the parts I chose are rated for it...main reason I chose them. Was more worried about the amps behind the battery, but I think I understand that a circuit will only pull what it needs, and wont get "pushed" by them. Is that correct...not sure how to say it but I know what I mean.

Yes, the latter is correct. At the given voltage(s) the load was designed for it will only draw its rated current regardless of what the power source is capable of.

Ron