Weak charging system? Solved

Hi all.

My 2011 4 banger had a dead battery after sitting for 8 days.

So I put a full charge on it and had it tested. Battery tested good.
I checked for parasitic drain. .12 milliamps. Thats a little high?

Checked the output of the alternator. Got 13.2 volts at full load at idle. (lights and fan and everything else)
The alternator is suppose to be a high output alternator I got from Bamatoy1997.

Is 13.2 volts at idle normal?
seems a little low to me.

Thoughts?

Thanks.

 

https://www.tacomaworld.com/threads...rical-system-upgrade-is-now-available.318682/

 

8 days shouldn't phase the thing. I've left my truck much longer than that and not had an issue.

Is this the stock battery? If it is, 6 years of life out of a typical lead acid battery is getting close to its effective life and you might want to replace it if the battery is losing voltage excessively.

 

Its a 2 year old interstate. I believe that it is good.
I question the drain and the alternator output. From what I have googled, 120 milliamp is large, and the alternator should put out at least 13.5.

 

Your first post here says .12 mA now it's 120 mA? That seems high.

 

My confusion.

 

.12 milliamps is high, but I believe there can be issues trying to read amp draw on vehicles with all sorts electrics that are easily awakened by traditional amp draw testing. Not saying you did this, just saying. Consider this is you haven't done so. The test checks milliVolts vs. amp draw, but you are still testing for amp draw in effect:

https://www.youtube.com/watch?v=B__DqK90IIc

Are you seeing 13.2V with a cold or fully warmed up engine? I always see 14.xV cold and 13.4V fully warmed up, but my vehicles are stock with no electrical mods.

 

I see the same voltage as Lester with no electrical mods.
If it were me I would go to Advance Auto, Autozone or whatever place you have near you and have them check the battery and alternator to see if they are charging / working properly.

 

Sorry for the confusion guys. voltmeter said .120

The 13.2 was registered with the engine fully warm and the electrical system under full load at idle.
I have never seen 14 volts. Ever. I have checked in the past with the engine cold. I could do that cold test again just to be sure.

The system was "fully tested" by the guys at interstate battery. I could go to autozone and see if they have any other test they can do. But the guy at interstate basically did the same test I did using a voltmeter.
Except for the battery load test that requires a special tester that I dont have.

 

.120 is .12 - and that's a lot. Maybe you have the vehicle loaded up with add-ons...alarm/etc - add-on alarm systems are notorious for causing parasitic drain.

13.2 with a warmed up motor and elect system under full load may not be too bad.

I would be more concerned about your amp draw. See the video above - build the wiring with resistor and start pulling fuses. If pulling all fuses doesn't bring the culprit to the forefront, you likely have an add-on that's thirsty.

 

I do have a bunch of add ons. Usb, radio, amp, blah blah blah. But I have them on a separate circuit that I can kill. Even after I killed all my add ons it still had the same draw.
The only thing I have put on that is not on that circuit is my remote door locks. I suspect they may be drawing a lot.

I will test it with a resistor first tho.

Anyone know what a normal draw should be on a 2011 base model? I suspect a base model should be .03 or less.
What is the normal draw on your trucks? If anyone has tested it.

The guy in the video says .35 millivolts is normal. That seems way high in my opinion.

 

With today's memory-laden gadgets(stock stuff included) - I would not be surprised if .050 were not unusual. If you use that as a measuring stick, you are pulling 2.5X more than that. I've never seen a value published for the 2nd Gen Tacoma.

Just my 2 cents

 

Now in curious... I'm gonna put my AC/DC amp probe on tonight and see what I get...

 

Keep me updated.

 

<<<=== Electronics technician.

I assume you mean .35 milliamps not volts.

Just to clear things a bit:

0.35 milliamps is equal to 0.00035 amps. This is pretty low. not perfect but your clock and stereo could draw this much just to maintain time and memory.

So 0.12 milliamps in your original post is equal to 0.00012 amps. This is very miniscule and insignificant as long as you have the milliamp part right.

With that being said if you are actually reading Amps, then 0.12 is a lot and you do have a problem.

 

My bad...he did say .12 milliamps in opening post.

 

Actually lots of people get this wrong and get confused reading the meter depending on if they are using a clamp on DC meter or reading it inline and getting the scale set correct ...

I only wanted to clear it up.

 

A typical "capacity" is 40 amp-hours. That it, the battery will provide 1 amp continuous drain for 40 hours before the voltage drops to the 8-volt threshold or so. Your 120ma figure will drain that battery in 40/.120 hours = ~330 hours. which works out to about 2 weeks or so. Yes 120ma is high. I'd hit the fuse box and pull one at a time until the amp meter drops significantly. Then see what is on that circuit.

So first question is, did you mean .12 amps, or .12 milliamps which is .00012 amps? There is a huge difference. 120ma is certainly high. 0.12ma is not worth mentioning.

 

I did like the video. Put in a resistor and tested that way.

On my volt meter I set it to mA At that setting it read .120 So is that good or bad? Im getting confused with all the different terms.

So I did some fuse pulling. I found the circuit which goes to my newly installed always on usb ports was pulling a lot. (I think)

When I pulled the fuse. The volt meter, in mA went from .120 to .07 So they are pulling a significant amount.
But I am not sure if that is a very small amount or not??

The other part I question is the alternator output. I see other getting 14 volts, but mine is at 13.2?

Appreciate all the comments guys.

Edit.

Just did another test across the battery terminals. 13.3 volts at 2500 rpm under load.
I wrote Bamatoy quite a while back about that. He said thats normal, but I question that. He is the expert on the subject tho, so I guess its okay????

One more thing. My multi meter has A, mA and uA I used mA which is the correct on I think.

 

I wouldn't call it the big 3 upgrade. I got a alternator that puts out 130 amps according to him.
I just wanted to bump up my system since I tow a small rv and have a large stereo amp.
The stock wiring is fine. I doubt I ever pull near 130 amps.