Battery Drain

[Knebel]

it happened to me twice now, that withing of 2 weeks, I wanted to start the fury and it would be completely dead. I dont drive it much at the moment (maybe once or twice in 2 weeks).... so I just recharged the battery and measured some parasitic draw.

I have installed: Fitech EFI, Radio, Avital 3300l security system.

I disconnected the efi and the security system and measure 0.02amp draw between negative post and terminal. When I plug in the efi, it goes up to 0.08amp. I would assume that the car alarm draws another 0.01 or 0.02amp.

Is that enough to discarge a battery down to no click no start in 2 weeks? It dosent seem a like a lot and i see that when i open the glovebix it has a 0.3amp draw. close it and its back to 0.08amp.

 

[Big_John]

How old is the battery?

 

[Mopars & Missiles]

You can figure it out mathematically. You know the current draw. You know how many hours are in two weeks. That equals A/Hrs. All you need to find out is what the A/Hr. rating is on YOUR battery.

 

[Knebel]

Its an interstate battery. bought in 2014, lost a cell or two in 2015 and got it exchanged for a new one. so its roughly a year old, but the last one gave me trouble after just a year too... what do i do? bite the bullet for an optima yellow top?

According to the math, it should last about 600hours or so....

 

[mr. fix it]

I believe that you have a parasitic draw .
You can quickly check this by having the ignition and headlights in the off position

Disconnect the negative battery cable then place a test light in series with the ground cable and the negative battery post

If it lights up then there is a draw pull fuses until the light goes out.
You then know what circuit to chase after.

 

[Knebel]

I have done the test measuring amps. 0.08amps

 

[Turboomni]

I had an interstate battery on my 97 LS 400 Lexus. The interstate was installed with a new alternator too. Told my mechanic starting was a bit slow ,and when it got cold rather slow starts. It was like it had no capacity and wouldn't take a full charge and store it. He replaced the interstate battery with another brand and said he has had a lot of quality problems with interstate batteries of late. My symptoms were not out of the norm. Replaced it and no problems.

 

[65sporty]

Have the battery load tested

 

[cantflip]

"I would assume that the car alarm draws another 0.01 or 0.02amp."

That has the potential to be the root of all evil here... I have trashed many aftermarket alarm systems over the years due to malfunctions including high parasitic draw...

Even at 80ma... you will eventually take too much from the battery... If you want to add so many consumers, do yourself the favor of making a starting/running ritual every week or get a nice automatic battery charger. I would normally recommend disconnecting, but that would defeat the purpose of your additions.

 

[Knebel]

Hmm okay. so at the moment i have the alarm disconnected. i have measured the battery voltage over the last 3 days, i see about 0.1volt drop over the last 3 days. so, fully charged at rest, i had 12.96v and 3 days later 12.86/87volt. it dosent look like it is draining rapidly. I plan on doing the test with the alarm connected too but that needs to wait after we moved, i need the car running in a couple days and not have a dead battery.

Cantflip, what would be a normal draw for a security system? mine is a two way with just a shock sensor, door sensors and hood pin. it also defeats the purpose having the car dead and alarm not working sitting there... well, i guess it sort of a safety feature too lol. I thought about getting one of those solar panel chargers to maintain what gets drawn.

 

[cantflip]

Not really a spec... unless the manufacturer gives you one. 50ma is a good place for lots of newer cars, but there are cars that draw way more... and go dead way faster. The solar chargers are something you would have to experiment with. I have 2 or 3 very old VW ones I tried to use to maintain some batteries in a travel trailer with mixed results. I would give them to you, but I doubt they are worth shipping. They have been sitting around for 15 years if I can find them.

Battery tender and many other brands out there for a trickle charger. the small ones can be permanently mounted in the vehicle and you have a detachable power cord you use when storing/charging... just make sure you fuse the B+ connection and use an outdoor cord and you should be ok. Not Ideal if you are street parking or far from an outlet... in which case, you should really just create a routine. It's better for the mechanicals to be run regularly anyhow... try to give 30 minutes driving or at least running whenever you can.

 

[Knebel]

I just measured again this morning and after sitting for another day the battery voltage went down to 12.62volt. I started the car (which it had no issues whatsoever starting) and took it for a 20 mile ride. My charging system is awesome now after the '70 dual field conversion and showed me between 14.5 and 14.8v the whole time. Back home, the battery was back up to 13.2v. I still have to find where my switched 12v looses almost 1volt. I just fixed a loose connector on the ign switch but that didnt do it.

 

[cantflip]

I just measured again this morning and after sitting for another day the battery voltage went down to 12.62volt. I started the car (which it had no issues whatsoever starting) and took it for a 20 mile ride. My charging system is awesome now after the '70 dual field conversion and showed me between 14.5 and 14.8v the whole time. Back home, the battery was back up to 13.2v. I still have to find where my switched 12v looses almost 1volt. I just fixed a loose connector on the ign switch but that didnt do it.

Just keep in mind that 12.68v is a fully charged battery... You shouldn't expect to stay above that level... this chart was really meant for solar panel batteries, but I liked the side notes regarding battery longevity

(I think the temperature correction is off)
The green zone in this chart should keep you from killing your battery too quickly. IMO the intermittent use and deeper charge cycles you are likely to have will shorten battery life, but batteries are going to fail unpredictably in the best circumstances too... you can go nuts trying to keep everything perfect.

My primary concern for you, with this problem, is the Fitech Keep Alive Memory (KAM)... I don't know much about them, but if you lose the KAM, you will have to restart the learning program from scratch every time that happens... defeats the idea of adaptive memory. I understand the EFI will be working from a base tune of some sort, but I have no idea how it gets the basic parameters to run... it's speed density so the controller needs some info for your engine to calculate airflow correctly.

After you have moved, I would be interested in how the alarm plays into your parasitic drain. At present, I see nothing to get too concerned about with your short term test... you know what your consumers are and how much they are drawing...

 

[Knebel]

Thank you for the reply cantflip. I am a little curios about the learning process of the efi too when the power is disconnected. There is a way to save a tune when its learned and then just "one button back it up" sort of thing, i just havent figured out how to do that yet. so far, the battery seems to be holding up...

 

[cantflip]

Thank you for the reply cantflip. I am a little curios about the learning process of the efi too when the power is disconnected. There is a way to save a tune when its learned and then just "one button back it up" sort of thing, i just havent figured out how to do that yet. so far, the battery seems to be holding up...

Keep us posted, please... you have become the "guinea pig" for several of us interested in knowing more about Fitech...

 

[Knebel]

Haha, thats fantastic. I dont really have any trouble with it tho. It dosent seem to learn quite 100% of what my engine asks for but thats okay, its mainly right after startup where i need to tweak. I actually saw the fuel cutoff on decel for the first time when i took it out recently. Nice to see no fuel consumption vs the holley sucking in even more... and its incredible responsive!

 

[Knebel]

Alright. Our move is done and i have plugged my alarm system back in. After a couple days (i want to say 3 or so) the battery was down to 12volts. I bought a small solar panel, plugged it into the cigarette lighter and the car sat for a week. Started right up today with no issues. Well, if thats what it takes, i dont mind leaving the solar charger plugged in...

 

[cantflip]

Alright. Our move is done and i have plugged my alarm system back in. After a couple days (i want to say 3 or so) the battery was down to 12volts. I bought a small solar panel, plugged it into the cigarette lighter and the car sat for a week. Started right up today with no issues. Well, if thats what it takes, i dont mind leaving the solar charger plugged in...

I am glad you have found a way to make it work for you. Aftermarket alarms have always been a bit of a PITA.

 

[Knebel]

Yeah, i would have never gotten it if i knew it was gonna drain the battery in a week. Hat defeats its purpose because the alarm wont work then either...

 

[Knebel]

"Resurrection". Interesting that now 2 years later, i am starting to have the same trouble with my battery. It is still the interstate and during summer and sunshine ihad no issues at all using the solar panel. My car would start no problem after sitting for a week or two. Now, i had the "click click" once alread after sitting a week, even with the solar charger plugged in. Today it would crank so slow i couldnt start it,so i jumped it. Sat for a week with the alarm system disconnected (at 30°F). I honestly think that the interstate battery is garbage. Has anyone experience with the optima batteries or any other better brand? I think i would benefit from a deep cycle one but oh my $250...