MM3 Draining Batteries?

[redneck3203]

I have been having a problem with my batteries going dead when parked for more than one day for the past few months.

I checked it, and with the MM3 plugged in, my batteries draw over 138 MA.

When I unplug the MM3 from the OBD2 port it drops to s 16 MA draw. Has anyone else experienced this and if so what was the fix other than just unplugging it when it sits overnight or the weekend?

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[AK Bob]

Yes, I also have the 138ma draw on my batteries.

The MM3 does draw 125ma while plugged in with the screen off.

Depending on your battery's age, state of charge, and ambient temperature, this can eventually result in dead batteries.

I am fine leaving it overnight or over the weekend.

If I am going to leave the truck parked for more than a week or two, I plug in a battery tender.

During the winter months (below 20*F), I have the battery tender and block heater plugged in on a timer every night set for 4 hours before departure.

As you mentioned, the other option is to unplug the MM3. If your batteries are going dead over a day or two with the 138MA draw, I would replace them.

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[redneck3203]

I have trickle chargers on my winterization, but if I forget to plug them in or if I don't use them now that it's warmer, they will go dead.

My batteries should still be under warranty, so if they are the case, I will get them replaced.

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[bigboost]

I'd agree with AK Rob; get those batteries tested.

Some rough math determines that 125MA should take over a month to drain 2 batteries to the point they would be too weak to start the truck.

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[redneck3203]

I'd agree with AK Rob; get those batteries tested.

Some rough math determines that 125MA should take over a month to drain 2 batteries to the point they would be too weak to start the truck.

I got the batteries checked.

That is the problem.

It's a good thing they are under warranty, so I won't have to pay for new ones.

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