Why does the old battery in my TB keep dying?

[l008com]

Ok, the title is a little loaded but hear me out. The symptoms are kind of weird and with batteries costing $200 a pop these days, I want to be sure I'm fixing the right problem.

So the battery is a few years old.

It will start the truck nice and easy most of the time. But then it starts to get weak. It still starts the truck but slowly over a period of days or even weeks, it gets weaker and weaker until suddenly one day, it's dead and won't start. So I jump it. Then I go home and a day or two later when I have to drive somewhere, it cranks right up like it's brand new.

I don't have a regular commute and the most common drive I do is between my current house and new house which is about a mile and a half.

Also I have aftermarket heated seats, but I'm usually driving alone. Low uses 1.5A and high uses 4.5A. Thats a lot of power but not enough that you would expect that to be the difference between charging or draining.

So I'm trying to figure out, is it just the battery? Or maybe is my alternator not creating enough power like it should? Or is something not turning off when it should, when I turn the truck off. So something is trickling down my power? But only sometimes.

The closest thing to a pattern I have noticed is that MAYBE it happens more when I'm using the heated seat on high more, when its 20° out.

I did have a 12v USB port charger for my phone I left plugged in, and I knwo those plugs are always on, so I stopped using that. It seemed to help for a while but lately not so much.

What do you think, any thoughts?

Maybe it's just a combination of the heated seats, the weak battery, and my short driving trips?

 

[Machoman]

To rule out a bad battery, Have it load tested at an auto parts store.

 

[Blckshdw]

It will start the truck nice and easy most of the time. But then it starts to get weak. It still starts the truck but slowly over a period of days or even weeks, it gets weaker and weaker until suddenly one day, it's dead and won't start. So I jump it. Then I go home and a day or two later when I have to drive somewhere, it cranks right up like it's brand new.

So as long as you drive the truck, it starts fine, but when it sits for long periods is when you notice the changes? If that's the case, then mine does this too. If I don't drive my EXT for 5 days to a week, it will crank noticeably slower than normal. Much more than a week, and sometimes it won't have enough juice to start.

Haven't dug very deep into mine looking for a parasitic draw, as it's pretty rare that I don't leave my house for more than a week anymore. From seeing another member's post, I bought one of those BT battery monitors, so sometimes I'll check it with my phone, and if it gets low before I need to go out, I'll stick the trickle charger on it.

 

[l008com]

So as long as you drive the truck, it starts fine, but when it sits for long periods is when you notice the changes?

No no not really, in fact kind of the opposite. I can drive it every day and it will get weaker and weaker. Then I can do one long drive and let it sit for days and it's totally fine. I drove to my uncles house Sunday, 2 miles away. I had driven to my grandmothers house on Friday, 2 miles away. It started sunday just fine but when I left maybe 6 hours later, it wasn't totally dead, but was too dead to start.

So I jumped it, went the long way home. Then Tuesday or Wednesday I started it for the first time after it sitting since sunday night and it started right up nice and strong.

During those short drives, I may have had my heated seat on high. If not, I surely had it on low.

 

[Blckshdw]

That's a head scratcher for sure. Having a near dead battery after 6 hours when it ran fine before...

This is the battery monitor I got, the contacts go under the terminal screws for a somewhat permanent install, but they have some that clamp onto the terminals for a more portable application. It could be helpful to see what voltages are being seen at the battery in different scenarios, so you know what factors are causing any changes without needing to pop your hood and check with a meter. Not to mention you can view things on the fly

Amazon.com

 

[budwich]

the question maybe be.... how are your non-oem heated seats wired into the system?
it might be wise to check your voltage at the battery (or lighter socket) to see how it is doing during your "events". My guess is that you have a stuck relay that is resulting in drains at various times ... but not all the time.

Of course, the other question would be: what voltages are you seeing at idle, at speed, at key off, etc... ?

 

[l008com]

the question maybe be.... how are your non-oem heated seats wired into the system?
it might be wise to check your voltage at the battery (or lighter socket) to see how it is doing during your "events". My guess is that you have a stuck relay that is resulting in drains at various times ... but not all the time.

Of course, the other question would be: what voltages are you seeing at idle, at speed, at key off, etc... ?

That was my first thought, but the seats have loud physical toggle switches and turning the seat on turns an indicator LED on, so almost any power drain at all through those switches should at least be enough to light up the indicator in the switch. I would think anyway.

I forget what I wired the relay to, It was probably ignition power or something. But the lights in the switches always turns off when expected so I don't think the seats are leaking power.

But are they draining more power than the alternator can restore in 15 minutes or less of driving? I dunno.

 

[Mooseman]

I'd still get the battery tested. It could have some sort of intermittent internal short. Also check the battery terminals and make sure they are tight. I've seen batteries that the bolts were tight but the terminals were loose against the posts. The nuts were loose inside the lead posts.

And most parts stores can test the alternator output in the vehicle as well as the battery.

@Blckshdw , that Bluetooth battery monitor is cool. Since I don't drive the TB a lot anymore, even though I usually keep a float charger on it when parked, I'm gonna get one of those. Could have saved my old battery.

 

[budwich]

That was my first thought, but the seats have loud physical toggle switches and turning the seat on turns an indicator LED on, so almost any power drain at all through those switches should at least be enough to light up the indicator in the switch. I would think anyway.

I forget what I wired the relay to, It was probably ignition power or something. But the lights in the switches always turns off when expected so I don't think the seats are leaking power.

But are they draining more power than the alternator can restore in 15 minutes or less of driving? I dunno.

the seat stuff was only one suggestion based on your information that you provided. The real info comes from the the voltage measurements and tracking thereof.

 

[azswiss]

Here is a post from @MRRSM on how to diagnose & find a parasitic draw.

How to Diagnose ANY Automotive Electrical System, INCLUDING How to find the Presence of a Parasitic Draw

 

[JerryIrons]

So the battery is a few years old.



What do you think, any thoughts?

Maybe it's just a combination of the heated seats, the weak battery, and my short driving trips?

When you say few years, how many would that be?

Have you put a meter on it to measure voltage? Also when the engine is running you can measure voltages, if you see 14 volts the alternator is charging the battery correctly.

Sounds like an old battery to me, or you may have a small parasitic draw from something. They can be a pain sometimes to figure out.

 

[l008com]

Well I bought the truck in 2016 and I did replace the battery once. I don't remember how far in. Lets ay maybe 4-5 years, possibly less.
I have not measured anything yet.

 

[l008com]

Today my truck wouldn't start. It cranked but not enough to start up. It was 25° today and I hadn't driven in a few days.
So maybe I simply have a poor battery. Maybe the fact that all my lights are LEDs has helped nurse the battery along to a point where the heated seat can kill it. I'll probably be picking up a replacement soon.

 

[l008com]

According to autozone, the battery is bad and the alternator is good. So I got a $160 autozone house brand battery and hopefully the diagnosis is correct and I'm good to go. It will be nice to be able to use heated seats constantly again

 

[l008com]

So far so good. Constant heated seat use, many short drives, nothing but powerful cranking.

 

[l008com]

Ok now things are getting too good. I've been getting a very steady 13ish MPG lately, unless I do a lot of highway driving, then it can get a little better. I got gas today and drove a few miles home and I was riding around 17 MPG. That's exceptionally good for this truck. Is this a thing? will a crap battery draw so much power from the alternator that it take a very significant amount of power from the engine? Or is this a calculation glitch in the computer that will work itself out with another day or two of driving?

 

[Mooseman]

I suppose it's possible that with everything electronically controlled that if it's not getting proper power, things won't work as well. And the alternator having to work harder might also affect it.

Enjoy!

 

[l008com]

Twas a glitch. Actually it was probably resetting the computer while the truck was fully warmed up and driving away that way instead of the usual ice cold start.