LT2300

HELP!

I have a '69 driver and have received a great deal of advice / help via the forum, for which I am grateful. The car has undergone a radical transformation and I would post pictures if I could figure out how. I can't even seem to figure out how to change my main picture, though, and she is now graphite metallic, not white.

Anyway, I have a persistent battery drain problem that is driving me nuts.

New battery, new cables. Tuff Stuff 140A alternator that came with a VintageAir FrontRunner and has been checked out by Tuff Stuff and certified as A-OK.

Much non-stock stuff. Relating to electrical there's a VintageAir Mark IV AC, the FrontRunner, a Model One radio, an AudioVox cruise control, and a hard-wired Whistler.

I have a disconnect on the negative terminal of the battery, the outgrowth of a near-catastrophic electrical short maybe ten years ago caused by the tach cable abrading the harness it ran across (as done by the factory). I added the disconnect after I fixed that, to give me a quick way to kill all in the event of anything similar ever happening.

When I disconnect and put an ammeter (set to the 10A range) across the two sides of it, I will initially get 0.04A that will settle to 0.02A after no more than a few minutes.

The problem is, if the car sits (which it often does even in the good weather), in a matter of a week the battery will be drawn down to 12.4V or even lower. If longer, certainly lower.

Given a draw of 0.02A, I can't imagine what's happening. Given my limited knowledge of electricity I can't imagine how 0.02A going out can take a good, 850 A-H battery from 12.6+V to 12.4-V in a week and down to 12.0V or less after two-three weeks. Further confusing me, recharge seems to occur very rapidly, with only a 1.5A trickle charger -- even when it's fallen to sub-12.

The drain happens independent of weather, and the car is garaged. I do know that it's actually draining, too, since it has gone to the point of not turning over, more than once (previous batteries -- I don't let that happen any more).

Does anyone have any idea what might be going on, or where I should look? Everything I've done / added to the car is in the main circuit. Nothing else to / from the battery. I've been puzzling over this for quite a while and am at my wit's end ...

lvmyvt76

start disconnecting the new stuff and find out which one doesn't drain the battery when left for a couple weeks. OR, you might use a meter to check for draw on the battery as you disconnect each item, see when the draw disappears, BINGO!

MakoJoe

Slow Leak Electrical problems are very hard to trace down. In your case I would do as the other member says disconnect your new radio equipment or run a meter on the power leads to see if it is drawing power when the key is off. Start with the new stuff first.

I had 2 slow drains that would kill my battery in 3 days that were difficult to find. First one I fixed was the courtesy light switch under the hood which fairly easy find since the courtesy light would flicker all the time even with the switch depressed. The other I had was my horn switch which would draw power even though the horns were disconnected. After replacing these 2 switches my battery drain disappeared.

How old is the battery? Sometimes if they are more than 3 years old and sit for long periods of time they will become sulfating calcification in a lead-acid battery on the lead in the battery and to keep this from happening a Float Charger will keep the battery warm and just enough current to keep the battery fully charged all the time.

Lead Acid Batteries will also discharge by themselves and have a natural discharge rate when not used. The discharge rate is even higher in NiCad and NiMH batteries than as all batteries age the natural discharge increases. With the Exception of newer battery Tech like Lithium Ion and Lithium Polymer batteries these will hold their charge for a really long period of time.

The slow draw you see when you disconnect battery is probably caused by capacitors in the newer electronics you have installed in the car. A capacitor will hold energy in them and slowly discharge after the power is removed from these devices.

BB2B

I use my voltmeter connected between the battery neg terminal and the neg cable, disconnected from battery of course and read the voltage draw. then remove fuses from the fuse panel one by one and observe where the drops goes away. now you have narrowed your search to a circuit.

LT2300

Thanks all, for the replies. I should probably have provided more info, but I'd thought the original post was getting too long.

The battery was new early last summer. The (minimal) 0.02A drain goes away if I pull the fuse from the clock circuit. I found that by pulling fuses one at a time, as recommended. None had any effect except the clock. All of the minor accessories I mentioned -- as well as the clock (quartz conversion) -- predate the problem. Never had a problem until after the AC addition. Thinking about it, I think that I need to pull that fuse and go for a few weeks, to see what happens. I think I may have tapped that circuit for the constant 12V for the radio (to preserve settings), so I may have to suffer in silence during that test. That circuit is also the lighter, but I rarely use that for anything and always unplug when the car is off when I do.

I added the AC and FrontRunner while the car's entire front end was off (having been trashed). The discharge didn't show itself until well after the car was back on the road. My first indication of anything was when it wouldn't crank. Happened a couple more times and I began monitoring (and replaced the battery). I left a multi-meter on it at all times (turned off) and would check regularly and put on the trickle charger when voltage began to drop off. I'd suspected a diode shorted to ground in the alternator, which is why I sent it back to Tuff Stuff, but they said it was good (very nice people, btw).

The AC and all related (electric fans, idle solenoid, etc.), are on separate circuits directly from the starter's hot through a power block and each is separately fused. I also ran a separate 8AWG wire parallel to the factory wire from the alternator out to the starter hot, because of all that had been added and the potential max output of the alternator (140A).

As noted before, all of that (AC etc.) is still part of the main circuitry of the car, and goes to the battery via the (new) 2AWG cables (starter to battery, battery to frame, block to frame).

The 0.02A drain is consistent with the quartz clock, I think. Again, what I don't know about electricity would fill volumes, but what I can't figure out is how 0.02A can take down a good, fully charged battery that quickly.

MakoJoe

Best thing to do is use a Float Charger when the car is parked in the garage.

The float charger will prevent the battery from the stuff I explained and keep it at a full charge since they only put about 0.6 amps into the battery while it sits. Enough to keep the battery from sulfating calcification on the lead in the battery and cause premature failure of the battery. Any drain that is caused by the clock in the car is also cured. Inexpensive Float Chargers can be bought at Harbour Frieght or even Walmart.


http://www.harborfreight.com/automat...ger-42292.html

http://www.walmart.com/ip/Grip-38020...arger/15041395

doorgunner

Brace yourself......my aftermarket radio which has a remote control....was turning itself on at different times. I kept the remote in the vehicle-not in my pocket), but the audio was silent. A couple times when I got in the car, the radio display was lit---I chalked it up to senility since the radio receives power from the cigarette lighter (I listen to it while working on the car & thought that I had left it on with the volume turned down ) It took two weeks for me to accidentally "catch it in the act"---the battery was dead/the radio housing was warm---exchanged the radio/problem solved.

Like the other members said....use a trickle charger if the car isn't driven in 7 days or more...just because you love your battery.

LT2300

Once again, the part of this issue that's driving me crazy is that I never had a problem, for a VERY long time (2nd owner, since 1974, a big reason for the additions I noted -- while it looks basically stock, it isn't by a long shot, as I've "improved" it over the years).

Anyway, before the front end was destroyed and the body shop owner suggested there would never be a better time to add AC and also allowed me to work on it in his shop while we were awaiting parts (how many shops will allow that?), this had never been an issue. All of the minor adds were done well before the incident that landed it in the shop. Again, that's why I ultimately focused on a grounded diode as the likely cause. When that turned out not to be it, I was tremendously disappointed and had no idea where to turn.

I understand all of the solutions and will likely wire in a trickle that I only have to plug in to begin charging (pretty much how I had the 1.5V I have, although it was always "temporary."

I do have some BE&E knowledge, but always tend to downplay it lest someone assume I REALLY understand electricity, which I don't. That's why I'm having such a hard time with this. I know what to do to deal with the problem, but there remain two questions that are causing me to lose sleep:

1) Why now, and not for the previous 30+ years I've had the car?

2) Can a 0.02A drain really take down a fully charged battery that dramatically? And even if so, see #1?

I spent a long time (25 years) in the Navy, so I'll quote a famous sailor: "Arrrgghh!"

btw, anybody care to give me some insight on how to change my main picture and add others? I promised "afters" several years ago when I solicited recommendations for a good body shop, but have never really figured out how to do it. I obviously attached the original picture, but have had no luck in even trying to change it, much less add more. I don't have any cloud accounts. The pictures I have are all resident on my computer, so please factor that into any instructions. Thanks again to any and all who have responded.