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**BIGEVIL** · 05-01-2009, 12:15 PM

2 words.

Battery tender!

**Morella** · 05-15-2009, 05:20 AM

I'm pretty good at knocking the sulfur out of the plates of a dead battery, but unfortunately, I would have to have the battery here, and I have a special computerized charger for doing it. I don't know the formula, although I have read it on the web. I do it more "by ear". Of course, I start by filling the water (distilled water, never acid), yes, even on the "maintenance free" batteries. They have caps that pry off just like any other battery, and they lose water like any other battery. I don't know why they call them "maintenance free". I'll have to ask my dad that sometime...I think he invented them when he was with Gould.

I have to watch both volts and amps and see what the battery is doing, but basically I hit it with 55 amps for a few minutes, then reduce it to 20 if and when it shows volts. The voltage will go down, which makes some people think that the battery is ruined, but not necessarily. If it eventually starts to come back up, I have succeeded in getting it unsulfated, and I charge it at 20 amps for a time calculated according to the battery capacity, or I stop if the voltage prematurely hits around 16, because that means that it has lost some of its capacity. Maybe the 100# sack of shit only holds 80 now, and I don't want to tear it. I finish it off with a 2-amp trickle charge. Honestly, though, I can't recommend that you "try this at home", because there are mistakes you can make that will make the battery explode. I have hit them with as much as 150 amps, but I don't recommend it, and please don't ever try to charge a frozen battery.

The solution that you really need has already been given to you. A lead-acid battery must be kept fully charged, or the sulfuric acid will soak into the plates, as your electrolyte turns into water. This is called "sulfating". They can actually freeze and break the case, like an engine block in a car that has a low concentration of antifreeze. Get an automatic battery minder, or a solar battery minder if you're not near an outlet. There's a caveat with the solar ones, though, besides needing sunlight. They're not water tight, and they'll probably tell you this in the instructions. If you're going to put it outside of the car instead of on the dash, or mount it on a boat, you have to seal the glass to the plastic frame. RTV black and some masking tape can easily do this.

I don't think I've ever answered a question in two words, but then again, I'm in pain and I can't sleep anyway. This stuff keeps my mind off of it, and if I can't work on my cars, I'll ramble on about them. That's why my posts are always a thousand words long.

-denise

**Morella** · 05-15-2009, 05:28 AM

One more thing...all batteries have an internal discharge rate, so disconnecting a cable may not save your battery. I like the little electric chargers that keep them at 13 volts, about $20 from Wal-mart or wherever.

-d

**travlinman** · 05-15-2009, 11:18 AM

If all else fails, and disconnecting the battery works for You, We use a master disconnect switch on the race cars. Just mount it where You can split the positive cable and its just a flip switch. It can even be remotely operated with a push-pull cable. Works good for the car shows where You can leave the doors open. Any type speed shop should have Them. This is 1 time stay away from NAPA, They are expensive there. Good luck.

**LMS** · 05-20-2009, 05:36 PM

You need to put a meter in-line with the battery and see how much current is flowing with the car off. Then start disconnecting things and fuses till it stops discharging. Something is shorted out bad to kill a battery that fast.

**Highbars** · 05-20-2009, 06:08 PM

Don't forget the charging system, test for proper output..no less than 13.0 and no more than 15..should be around 14.5. If you have a diode out in the rectifier bridge or stuck contacts in the mechanical Regulator..depending on type of alt. internal or external voltage regulator it could be back-feeding thru charging system with ignition off....

If it is overcharging it can also damage your battery and it won't hold it's charge

**TWHawk** · 05-20-2009, 07:26 PM

Helen has a kill switch that keeps her battery from draining like that. She also has a tendancy to shock the crap out of you if you touch her in the wrong spot while she's running, so I second the opinion that there could be a short somewhere.

**Morella** · 05-20-2009, 07:28 PM

It looks like you have a lot of good advice here.

What is the shortest time it has taken to drain? All I could see in your was a year, unless I missed something, which is quite possible. I've found that 1-2 months is the longest that they go with normal switch-off accessories like clock/radio memory and alarm, and after 6 months with the cable off, it may not start. Besides, a lead-acid battery should always be kept fully charged. We call them 12v batteries, but the cells, when static, usually measure more like 12.6-12.8. Temperature also affects everything in the electrical system, including the battery. They drop quickly to 12v when any load is applied, but if they read less than 12.5 with nothing connected, you should probably give them a trickle charge. The best thing really is a battery maintainer. My Mercury sat for three or four weeks without a charger, but with the alarm set, and it has taken 48 hours for a trickle charger to bring it up near normal.

Some 70's cars had a steady drain through the seat belt interlock system, and the best thing to do is yank that whole system out and bypass it.

An overcharging alternator is usually evidenced by a large battery acid stain across the top, from electrolyte boiling out. One time, I heard a noise like an animal breathing, and when I opened the hood, the battery was like a living thing, expanding and contracting in size and making breathing noises like a wounded animal. That was sort of freaky, and maybe the electrolyte was just low, but I was on the highway, so I just bought a new battery.

Sorry about rambling on so much. I like electrical stuff.

-denise

**Morella** · 05-20-2009, 07:29 PM

She also has a tendancy to shock the crap out of you if you touch her in the wrong spot

Sounds like a woman with a stun gun.

-denise

**EvilManor** · 05-21-2009, 10:27 AM

I don't know an actual time frame, but it will kill a battery over night and twice it's done it to brand new batteries.

I'm planning on using the meter and doing the pull/replace fuses this weekend.

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Killing batteries?!?

Killing batteries?!?

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