fuel guage causing power drain

[bruceb58]

Re: fuel guage causing power drain

Now you're cooking...! That's the most direct way to look for a current draw. Resistance checks can help to break down a circuit once that circuit has been determined to be faulty, but it's seldom the best initial move in checking a boat (or automotive circuit).

If you're sure of the .002 amp draw with everything shut off, that is something you should pursue. That represents a 600 ohm load, and will reduce your starting capacity over a period of weeks. 600 ohms could be something like an accumulation of grease or moisture across a pair of terminals (+ to -) somewhere under the motor cover. It could decrease on its own over time, but could also increase with time. No emergency, but if it were mine I would go over everything that could be so exposed with a good light, a non-conductive grease/moisture remover and a small brush.

First of all, I think you meant 6000 ohms not 600 if you are simply using Ohms law and 0.002A as your current, and second, you can't really determine current draw with a simple resistance measurement because if its a circuit with active components that cause that draw, you would never be able to measure it with a resistance measurement.

I would also like to know where 0.002A was mentioned! I also doubt a $20 meter can actually measure a current as low as 2 mA.

If he really did have only a 2 mA drain, his battery is self discharging faster than what that current load is causing. 2 mA is going to take years to discharge a battery.

 

[glenn property of pam]

Re: fuel guage causing power drain

getting a little arguementative over 20 ma which is 0.020A like any one realy cares it not like we are calibrating a pressure sensor on loop power in a nuclear plant. the meter is either out of calabration or you do have a tiny draw which is proberly dirt or moisture on the terminals. either way its good preventive care to go ahead and clean the terminals even if its a false read. realy glad you found the problem and in the process you have learnt that modern electronics are vampires which is why a dual switch or battery disconnect is worth thinking about. on a bad note check the battery if it went real low as they have a bad habit of failing when they have been fully discharged.

 

[generator12]

Re: fuel guage causing power drain

First of all, I think you meant 6000 ohms not 600 if you are simply using Ohms law and 0.002A as your current, and second, you can't really determine current draw with a simple resistance measurement because if its a circuit with active components that cause that draw, you would never be able to measure it with a resistance measurement.

I would also like to know where 0.002A was mentioned! I also doubt a $20 meter can actually measure a current as low as 2 mA.

If he really did have only a 2 mA drain, his battery is self discharging faster than what that current load is causing. 2 mA is going to take years to discharge a battery.

Easy Bruce. I mis-typed - should have been .02A to represent the 20 mils the OP mentioned. Beyond that I stand by everything else in the post.

 

[mbfish]

Re: fuel guage causing power drain

I'm planning on a battery switch as I now have two batteries because, long story short, I thought the first battery was done. I'm just working out the details. Do you guys recommend putting the second battery in the front? There is already a battery tray next to the first one, at the stern. However, I don't need any more weight back there.

 

[bruceb58]

Re: fuel guage causing power drain

Easy Bruce. I mis-typed - should have been .02A to represent the 20 mils the OP mentioned. Beyond that I stand by everything else in the post.

You still can't just measure resistance to find where 20mA is coming from.

I would pull the fuse going to the stereo deck to see if the 20mA is coming from that. I have a separate switch going to mine to make sure it is completely off. The best way to isolate which circuit the current is coming from is to pull fuses and be measuring current.

As far as where the other battery is to go, I would never put a battery in the front of a boat. First of all, there is way too much pounding that would kill the battery and the length of cables that you would need would require a large increase in size so you wouldn't get a voltage drop.

 

[mbfish]

Re: fuel guage causing power drain

Alright. Thanks for the input.