Another new battery drained within 3 weeks

If your truck had a good parasitic drain,, it would be dead.. Not trying to be a wise ass,, just saying

 

Dude it sat for 3 weeks. The battery still drains slowly if it hasn't been turned on. That's any vehicle

 

Same here since January of 16, first winter was in Cleveland the next two were in NH and have been in PA since. Still going strong.

 

Yes sir you are correct, but should be OK for 3 weeks to start !!! The modules wake up and go to sleep over and over. Any car that sits over 5 weeks I would suggest putting a battery tender on it for sure...

 

My truck can sit for weeks with no problems starting, must be that aftermarket alarm causing the problem.

 

100 ma draw for three weeks will lower the voltage, add that to freezing temps. I could see any battery getting weak. If your not going to drive it for over a week, put it on a good charger.

 

If I remember correctly GM sued them for battery warranty claims a few years back...

 

Any thing that did not come with the truck is always suspect.

 

There are only 3 flooded acid battery manufactures in the US but a lot of rebranded batteries.

 

Any thing that did not come with the truck is always suspect.

 

The chances of the drain being OE is very, very low. Here is what you do. Get yourself a VOM meter. Set it to amps and put it in series with your battery to measure the drain with key off. Anything above say 30mA is questionable with everything else off. Then go to the fuse that powers your add on alarm and pull it. Look to see if the amps drop. Bets are it is related to what you added to the truck.

 

In my experience...3 weeks in winter is pushing it. Doesn't surprise me at all that it was drained. I haven't personally tested it on my Tacoma, it has never sat for more than a week but I've had plenty of batteries go during the winter on other cars left sitting. My OEM Toyota battery has been surprisingly good. It's over 4 years old and going strong even with additional load from aftermarket stuff.

 

Replaced my MIL's RAV4 OEM battery today with an Interstate. The OEM was dead if it sat for more than 3-4 days. Dealership couldn't find anything wrong but still replaced it last spring. RAV is all stock. If it continues she is trading it for a Subaru.

 

I installed a knife disconnect on my truck and an AGM battery. A disconnected AGM battery can sit for many months with little discharge. I too had my OEM battery fail after about 18 months. Got it replaced under warranty. Didn’t trust it so i got the AGM. I am gone for two or three months at a time. If i can’t get a tender on it, I disconnect the battery and it starts right up when I get home.

 

I kept killing batteries when I had a 2 mile commute. Not enough time charging will cause sulfation and over time will cause it to not take full charge no matter what.

What is the commute like on the taco time wise and how often is it driven? Mine's on a maintainer because I drive it on the weekends due to (edit) wfh. Plus the temps are going down which is another factor. You might have a parasitic drain but if you're also undercharging your battery, it's exacerbating the issue.

 

Ok good plan, so I charged the battery, bypassed hood ajar button and turned everything off. I start out with ~200ma of draw which after a couple minutes seems to settle around 78ma with a couple ma fluctuation. I pulled all radio fuses and #1 did drop the draw to ~61ma. What is normal for this truck? What is normal for a head unit?

Thanks again for all the help. Let me know if you have any more insight.

 

I also live in Ohio and if I left a vehicle sit for 3 weeks in 30 degree weather the battery has about a 25% shot at starting the vehicle, if that.

 

Not saying this is your predicament, but...Twice, I've purchased old batteries that have set on the shelf (poor stock rotation prolly) for too long. One time I had to eat the cost, the second time, I caught it in time. Now, I verify their age before I buy. Annoying lesson for me to learn.

 

I have not seen any mention of checking the water levels. I just had to top mine off the other day. Did you check?

 

I'll probably try to figure out which circuit the Viper remote start is on. It maybe on the radio one and in that case I'd have aftermarket headunit and remote start drawing that extra 18ma. Then I can research what the draw from those should be. I will report back. As an additional note my BMW just sat for 4 weeks and just now gave me a battery low warning. It did start, but that car has a big ass battery in it comparted to the little taco one. Will these larger AGM batteries take longer to drain? I assume so based on your comments above it looks like it'd be 76ah.