Parasitic Battery Drain

[Jerzfj40]

I am having problems with a parasitic battery drain on my SBC fj40 cruiser. I am running dual batteries (Optima) which i have already replaced twice because of early battery death. Im no electronic whiz, so somebody help me out here. The batteries will go completely dead after sitting for 2 weeks with no driving. The only accessories that are hooked up "hot" are the Auto-meter quartz dash clock and the radio. I am getting a 58.0 milliamp draw from my starter battery when truck is parked and everything off. When i disconnect the radio from the fusebox, it drops to 15.66 milliamp draw. Does a 42.34 milliamp draw seem reasonable for a radio's memory?
Also as i pulled each fuse to find any further drop in milliamps, when i got to the brake light fuse, the draw went down to 03.76 milliamps( radio still unplugged) I still have not gotten to the quartz clock yet to unplug it, but i cant imagine it would be the cause of the remaining 3.76 milliamps being drawn.
Anybody have a clue as to what i should do next?

 

[fieldsken1]

use a battery tender thats what i do

 

[Jerzfj40]

Actually, i use the dual battery tender, but id rather find the problem causing the drain so i dont have to constantly hook up the batteries every time it sits for a few days

 

[3jvj]

Mine is retaradiculous. There's a switch that has "1","2","ALT", and "off". If I plan on it being parked for more than two I kill it. You could go with an rv/ snow plow isolator. It will leave your run battery safe when the other goes down.

 

[3jvj]

Have you load tested your batteries? I've heard if you run two on the same curcuit they need to be the same or they'll kill each other. Just what I've heard.

 

[fieldsken1]

ok heres goes. seperate them with an isolator and put all the assc on one and use the other for starting. like the other guy said if you are running them in paralarel they must be the same or they will feed off of each other and kill themselves. i am running 6 off road lights and stereo and cb and wench on one and the main stuff on the other and it works fine. i dont use a dual battery tender whoever i do have a battery tender wired into both batterys. i have a wire setup running from one to the other battery that i plug together to charge and unplug when no charging to seoerate them. as far as a drain it does not take much with the optimas maybe an odessey might be better

 

[Jerzfj40]

I have a " Painless" dual battery isolator set up so that is not the problem. My second battery is only wired to my winch and that side is showing no draw on the battery. Im thinking that there is something going on with the "brake" fuse drawing almost 12 milliamps when sitting.

 

[Pin_Head]

50 ma doesn't seem like it would be enough to discharge two red tops in two weeks. They are something like 600 amp hour batteries, so it would take a couple of years to discharge them by half.

Maybe the batteries aren't as good as you think.

 

[Jerzfj40]

These batteries were just purchased this week and i made suer they were fully charged before i tested them today

 

[Jerzfj40]

Also, this time i got a deep cycle yellow top for my accessory battery feeding the winch, and the starter battery is the red top.

 

[fieldsken1]

just because they are new does not mean they are good. i replaced 1 of mine after 1 week. anyway check to see what volts it is when a full charge is done if its about 12.5 or so its no good. the one i replaced wsould not charge over 12.5 or so not enough. sorry about the spelling i am driving across iowa

 

[Jerzfj40]

My yellow top was 13.55 fully charged and the red top was 13.08. But i think im on to something here. I disconnected the plug from the alternator and then checked the draw on the red top and it dropped down to ZERO! So , i lost the last 3.76 mA of draw showing up.
Now my questions are :
1. Should the alternator have ANY draw on the battery when key is off?
2. Is 15.66 mA normal for a radio memory?
3. With the Brake light fuse back in, i have 11.85 mA being drawn from the battery. Would a bad brake light switch on the brake cylinder/ resevoir cause this?

 

[fieldsken1]

number 1 NO numder 2 thats not enough to worry about number 3 yes it could

 

[fieldsken1]

first of all if you are using the painless kit the batteries should be the same not nessercy but it would be better

 

[Pin_Head]

How are you making the current measurements? You need to disconnect the battery cable and put the amp meter in series between the cable and the post. 3 mA is a tiny current for an auto battery and the alternator could normally sink this amount of current, but I don't know for sure.

 

[Brian in Oregon]

I have the same problem, only mine goes dead after a week. I installed a $5 kill switch on the battery terminal.