How to check a Parasitic Draw on battery

[shelly4278]

Does anyone know the cheapest way to check for a battery drain? My battery has slight draw. I do not know where it is coming. from. I have a 2005 S40. I replaced the Battery about 10 months ago. The battery has been checked and its a good battery. I am checking to see if lights have been left on and still cannot come up why my battery is draining.

[JDS60R]

Lots of post here on the topic. use the search above.

Basically
1. Remove positive battery cable
2.Place meter with amp draw setting between battery and removed cable.
3. Pull fuses one at a time until you find the one or two that effect the draw reading on the meter.
4. Inspect/unplug the devices on that circuit until you find the one with the draw.
5. Repair as needed

[shelly4278]

Thank you for your response. I just called a automotive repair shop. They said for $15.00 they could check for the draw. If it takes more than a hour then they will charge for Labor. I'm thinking its a fuse. The Alternator Test out fine.

[JDS60R]

A fuse does not draw any amperage. It only limits the total amount of flow. It will not be the cause of the draw.

[shelly4278]

Do you think it is a relay. What draws ampage?

[JDS60R]

Everything that takes electricity to run will draw amperage (lights,radio,sensors,gauges,fuel and air pumps,horn,airbag monitor system,engine computers etc)
They are switched on and off by the use of switches ,relays and computers.
Wires provide a path for the electricity and fuses protect the wire from burning up in case the device tries to draw more amperage than the wire can handle.

[shelly4278]

I took my car to my Mechanic today and he is going to run the proper tests on it. I will get back to you and let you know what caused the drain.