2007 Odyssey Battery drains

im2ez4u

Does anyone have a problem with the battery draining?
If I don't drive my 2007 Odyssey for several days the battery drains to fully dead.
I recently changed the battery (which was close to 5 yr old), but it still happens.
How do I check the electrical system to determine which circuit is draining the battery?
Also, Iv'e noticed that I'm getting a little water accumulating in rear cargo area, making carpet mildow.
Not sure if these are seprate issues, or related. Can anyone help?

thecardoc3

The answer is two fold, and you need a very accurate voltmeter to do this. The first step is to measure the current that is being drained from the battery. One way to do that is with a voltmeter that can measure amperage. Most good meters that can do this will carry up to ten amps of current. You have to connect the meter to the negative battery cable and the negative battery post so that any current flowing has to pass through the meter so it gets measured and displayed, and then pull the cable off of the battery leaving the meter connected. Use of a jumper wire to help change from the cable being connected to only the meter in between the cable and the battery will help.

Once you can see how much current is flowing and if it is greater than .030 amps (30 milliamps) then you take a second meter and start measuring for a voltage drop across each fuse. Every fuse is a resistor that basically heats up and melts if too much current is flowing across it. OHMs law teaches that when you have current flowing across a resistance, it will cause a drop in the voltage across that resistance. Now we are not talking about a very big number, in fact it will be in the .00XX or X.X millivolt range so accuracy of the meter down to .001milli-volt or 1mirco-volt is essential. Any fuses that show any when you voltage measure across the fuse has current flowing through it.

The old routine was to pull fuses to see if the draw once measured went away. With todays computerized cars that sometimes causes the drains to go away and stay away when the fuse is put back in until the next event, that's why we use the voltage drop method today.

If you find a shop/tech who knows the voltage drop method they will make easy work of locating the drain for you.