dustin11

I installed a new AMS mini battery, started the car up and let it idle for a few minutes to make sure it worked properly, then a day later the battery was nearly 100% dead and I didn't even drive it anywhere. No lights or electronics were left on and the only after market part connected to the battery is a car alarm. I'm thinking that maybe a rodent got under the hood and chewed up some wires so exposed wiring is touching metal or something. That or something isn't being shut off properly like it should be when I turn the car off. any advice?

I<3Boost722

Do you have any type of sound system in the car?

dustin11

No, just the factory system. I've owned the car for a little over 3 years without battery problems and without installing any aftermarket parts. This last October my battery died so I replaced it with another Odyssey 680 mini battery. Then it turned out to be my alternator so I replaced that but my battery kept dieing. I then got my battery tested and it came up as "totally dead" so I went out and bought the AMS battery and am still having the problem.

NWM_Tech

"something isn't being shut off properly like it should be when I turn the car off"

possible, test for "parasitic draw" should be around/under 30 to 40 milli-amps, about 60 mille-amps max

"it turned out to be my alternator so I replaced that"

AM or OEM? Most AM alternators are one of the most problematic AM parts out there.

dustin11

OEM alternator. I know that its not anything to do with the alternator because the car wasn't driven after the battery was installed nor was it at idle for long enough to drain the whole battery. How do I do a parasitic draw test, and what tools would I need for that?

NWM_Tech

"parasitic draw test" Google search gets a bunch of hits, but THIS ONE (pdf) looks the best to me on the first page.

you might check the obvious before hand, like is the trunk light or dome light staying on. Sometimes the dome light switch is barely shutting off. With door closed wedge something that won't mar the paint and pry the door in the open direction at the bottom.

careful when you put your meter to the mille-amp range, don't open the door unless you've disabled the dome light switch, don't turn anything on at all. It will pop the fuse inside the meter (if it has one).

basically you're removing the neg battery cable and connecting the meter in series between cable and battery and measuring amps and mille-amps. Key off. If it's over 40 mille-amps you then narrow down by removing and re-installing one fuse at a time until the amps drop. Duct tape the dome light switch off, and close the door latch with the door open(there's usually a switch in the latch that controls the key chimer), so you can keep the door open to check under dash fuses. When you find the fuse circuit then disconnect, one at a time, the items on that circuit.

My favorite one is the Honda Odyssey where the coin holder is right below the CD changer slot on the dash, most Odyssey owners have little kids... Take out the CD player and it ching-chings like a piggy bank.