Sea Ray

If you have outdrives, the Mercathodes also pull power as they are directly wired.

Step 1: Fire that mechanic and never recommend him to anyone.

Step 2: you have a very heavy pull on your batteries, if it is less than 10 amps you should be able to put your digital Volt ohm meter (DVOM) in line of the positive or negative terminal and read you amperage draw. (you can find you ture videos on how to do this if you are not familiar)

Step 3: start pulling fuses until the large amperage draw falls off.

Step 4: Identify everything on that circuit and start unhooking those items one at a time, again looking for the amperage drop.

**Note: anything under 100mA is considered a normal draw.

***Additional note: all of the above tests need to be performed with the battery chargers turned off. I guess another possibility that needs to be worked out is to determine if the battery chargers are even charging properly. (I would confirm this prior to jumping into the above steps, other than step 1)

I apologize for the typos in my previous post, I am usually pretty good about going back and correcting my phones horrible text predictions.

In electric problems you start with the source. That would be the battery. Make sure all connections are clean. If acid flow make sure your batteries are not dry (lacking water). Caps under sticker. There are a couple of test with inexpensive equipment that can determine a battery state. A battery tester with all of the boat leads removed put under a load test (stress test) if the battery will draw and if it does not return to 12v battery has a problem. If you have more than one battery in series a bad plate will discharge even the good battery. Possibly you have one bad plate drawing the others down. A inexpensive Hydrometer will tell you if you have a bad cell. With batteries with full charge reconnect. Next step would be to look for bad ground. A bad ground will send energy out where it is attached. You can check this with a simple 12v test light by attaching one end to the ground and the other to some metal if you get a draw clean that point.
The other way is to have a volt meter on your battery and watch the draw and disconnect devices one at a time and watch voltage drop. When you find the high draw that is it. Problems like this drive mechanics nuts.. Good Luck!

I had a draw issue and found out that I had a short by trial and error. I have my stereo on for hours with the charger on and my batteries never lose power

One of my stereos has a two level off button. Click it once and it’s more like a mute button, the display stays on with the clock shown. Hold it for about 3 seconds and everything shuts off. I’m not positive but I think it’s a Clarion.

I've had couple boats with hard wired carbon monoxide detectors that drain the batteries. I put switches on them and turn them on when staying on boat.

I also have had my stereo on for hours and have never had a problem..

So I just helped a guy on my dock last night with an issue identical to this. His battery charger had been replaced about a year ago. It has a power button on it, and just simply needed to be pushed to be turned on. Problem resolved.

Had similar, it was my charger/inverter.