Parasitic drain on 2003 Taco?

[DaveM]

Battery on my 2003 Taco recently died so I replaced it with a new Sears AGM battery. When I check the old battery I noticed heavy corrosion on the negative terminal. I cleaned it off, put in new batt and then only two weeks later I see its’ again heavily corroded. Does this signify a parasitic drain or some other bad wiring in my system?

I did a check today with a multi meter, here are my results:

Battery hooked up, truck off: 12.77v
Batt unhooked: 12.79v
Batt neg hookedup, pos unhooked with multi meter connected between pos post and pos cable: .05 amps
Batt hooked up truck running: 14.12v

I have an aux fuse system installed but I don’t see any change when I disconnect the main fuse.

What do you think?

 

[cruiseroutfit]

.05 amps is extremely realistic as a normal drain, your dash clock, ECU, radio and possibly others will pull a small amount load. I can't picture the corrosion having anything to do with the drain, that is usually a sign of a venting battery and seems to be worse off on Toyotas do to their use of standard steel clamps versus lead based clamps.

 

[proper4wd]

Yes the corrosion is due to the battery venting.

I used to fix this on Land Rovers by cleaning the whole area (baking soda dissolved in water works great), and after the corrosion is gone spraying Waxoyl 120-4 on the terminals, being sure that everything is coated.

Here is a description of Waxoyl 120-4: http://www.roversnorth.com/waxoyl/waxoyl-corrosion-prevention.html

The stuff is great, I usually have a few cans on hand for random corrosion prevention tasks.

 

[DaveM]

Yes the corrosion is due to the battery venting.

Do Optima AGM type batteries vent? I thought they were sealed?

Anyway, as long as .05 amps doesn't seem like too much drain then it must have been a coincidence. It looks strange because its only on the neg terminal and it comes back fast.

 

[SEREvince]

You're not alone. Not that that's any help

I have the fast growing variety of corrosion as well. My ground terminal is generally much worse.

I plan on switching my terminals to something like this this.

 

[obscurotron]

Which Sears AGM battery did you buy? They told me there was no application for a 2003/2004 Tacoma.

Battery on my 2003 Taco recently died so I replaced it with a new Sears AGM battery. When I check the old battery I noticed heavy corrosion on the negative terminal. I cleaned it off, put in new batt and then only two weeks later I see its’ again heavily corroded. Does this signify a parasitic drain or some other bad wiring in my system?

I did a check today with a multi meter, here are my results:

Battery hooked up, truck off: 12.77v
Batt unhooked: 12.79v
Batt neg hookedup, pos unhooked with multi meter connected between pos post and pos cable: .05 amps
Batt hooked up truck running: 14.12v

I have an aux fuse system installed but I don’t see any change when I disconnect the main fuse.

What do you think?

 

[Tucson T4R]

FWIW, I had minor corrosion with the stock Toyota battery bust since I cleaned it up and installed the Odessey AGM battery I have not seen any new corrosion form in the last year.

 

[DaveM]

Which Sears AGM battery did you buy? They told me there was no application for a 2003/2004 Tacoma.

Die Hard Platinum. None of them are a stock fit but the P-5 (group35) is very close and is the only one with the terminals in the correct arrangement.

 

[obscurotron]

What mods (if any) did you make to the battery tie-down (or anything else) to make it fit snug and secure?

Die Hard Platinum. None of them are a stock fit but the P-5 (group35) is very close and is the only one with the terminals in the correct arrangement.

 

[DaveM]

What mods (if any) did you make to the battery tie-down (or anything else) to make it fit snug and secure?

None yet. I was going to look into aftermarket straps, or just cut some aluminum angle bar and slip it under one side of the bracket to fill the gap.