Battery Kill Switch & Charger questions

[Guest galenmd]

I am driving my '49 Super convertible with original 6V system. First, I plan on an electrical overhaul with a new YNZ harness. I am saving up for the big $$$ and time associated with that.

I have installed a battery kill switch. Problem is, it only installs on the negative (ground) terminal).

A few days ago, my battery was completely dead and would not accept a charge. The kill switch was activated (disconnected). Fortunately, the battery was replaced for free.

I don't know why my battery died. I didn't see anything left on. Perhaps it was defective, but it held up great for 2 months with never a failed start. I am afraid this could happen again. I am wondering if there is a drain somewhere. Wouldn't the ground switch prevent that? Am I better off with a Positive terminal disconnect? I am having a hard time finding one.

Also, can someone recommend a good battery charger/starter for a 6V system? Seems that all the special features on most (automatic, starter, etc) are geared only for 12V.

Thanks for any help.

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: galenmd</div><div class="ubbcode-body">I have installed a battery kill switch. Problem is, it only installs on the negative (ground) terminal).

Am I better off with a Positive terminal disconnect?Also, can someone recommend a good battery charger/starter for a 6V system?</div></div> Your kill switch doesn't know which side you put it on. If you are installing close to the battery, install on the terminal that is NOT connected to the body. (My car is 6-volt, positive ground, so my disconnect is on NEG.)

Here are two chargers that work for all your cars:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=3418

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45005

A word of caution; charge your battery s-l-o-w-l-y (2-amps is very good). Charging too fast will dammage your battery.

[Guest galenmd]

Thank you, simplyconnected.

The kill switch only fits on the negative side. The terminals are different sizes with the negative being smaller. I tried to stretch the switch it to fit on the positive terminal, but cannot. Maybe if I try really hard with a vise...

I am 6-volt, negative ground. To change this, can I just switch terminals, or does that require other re-wiring?

[Guest simplyconnected]

There is nothing wrong with breaking the neg side. In fact, some owners prefer it. The most common practice is to break the positive side, but it really doesn't matter which battery post you disconnect. <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: galenmd</div><div class="ubbcode-body">I am 6-volt, negative ground. To change this, can I just switch terminals, or does that require other re-wiring?</div></div> I don't know what you intend to change. Negative ground is very much standard, even today. Stay with negative ground.

My car model was the very last year for positive ground AND six volts. The next year, all models were 12-volt, negative ground. That was a dramatic improvement that I wish my car had.

Not all cars followed today's 'norm.' My cousin's 1965 Amphicar has 12-volts, but positive ground. It's a pain to deal with. Try buying a radio or electric fuel pump (or bilge pump); nothing is made with positive ground, today.

[Guest galenmd]

Thanks again.

I am strongly considering converting to 12V. I can get easily jumped if needed, replace the battery without hunting around, install a real stereo, charge a cellphone and Bluetooth (handsfree required in California beginning July 1), have brighter lights, etc.

I don't know if this is something I can do myself. I have no idea how to install an alternator. Resistors and lightbulbs are easy. I will have to change my electronic fuel pump.

[JohnD1956]

The battery being dead after two days with the negative terminal being disconnected is most likely just an issue with that battery. There is no real advantage to disconnecting the positive terminal over the negative terminal. In either case on a 49 there should be only one connection ( battery cable) at each terminal, and if your kill switch is in between the battery and the cable, then you will not have a complete circuit and nothing will have the ability to drain the battery. Chances are the battery you had was defective.

[Guest galenmd]

Thanks, John. That makes me feel better.

[JohnD1956]

No argument from me about Daves post here, except two considerations. I find it hard to believe that the 6 volt system would be in discharge mode whenever you use the headlights and original radio or none of these cars would start the next day when they were new. Also, do the math on how much you'll have to drive to recoop the investment in time and money to make this conversion. Do you do a lot of night driving? If so in my opinion the money on an electrical conversion would be better spent on a new windshield so you can see the road clearer. But as the price of fuel continues to rise, chances are the car will spend a lot more time in the garage. So is this change truly necessary?

I definitely agree with Radial tires. But a properly operating 6 volt system really ought to be enough for your car, with the exception of a modern stereo. I wonder if a modern stereo can be powered off one of those power boosters they sell today for jumpstarting cars? If so you can always bring that inside and re charge it for the next day's drive conveniently enough.

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: galenmd</div><div class="ubbcode-body">I am strongly considering converting to 12V.

I don't know if this is something I can do myself. I have no idea how to install an alternator. Resistors and lightbulbs are easy. I will have to change my electronic fuel pump.</div></div> Ok, NOW you've done it. Most folks around here are purests. I am not. I believe you should 'upgrade' your car to suit your current situation (unleaded gas issues, radial tire issues, electric wipers, seat belts, etc.).

I think changing to 12-volts is very necessary, especially if you actually DRIVE your car. Let’s do some math:

Your 6v generator probably puts out 35amps. 6v X 35a = 210Watts of power. That’s TWO-100watt light bulbs, and only when your engine is running fast. Running headlights & radio, you are draining the battery while your generator is putting out all it can. Your 6v battery is around 800amp/hours and costs twice as much as a 12v.

12v system: 12volts X 55amp alternator = 660watts. SIX ½(not two)-100watt light bulbs. That's three times the power. I’m taking very conservative figures. Most alternators put out 95amps on standard cars. They charge at idle speeds, and deliver more than 1,100watts of power. 12v batteries are only 500amp/hour and deliver twice the power of a 6volt battery, at half the cost. You can easily see, there is plenty of spare capacity in a 12volt system.

Most alternators bolt right into the very same place your generator mounted. You may need a few shims because the alternator is smaller. And most conversions involve a GM one-wire alternator. It’s hard to find one under 55 amps, and the regulator is built-in. You can do this conversion in one Saturday afternoon, if you have all the parts. By the way, you need all the parts at once.

Throw your old regulator away. You will never ‘flash’ a field again. There are several things you need to supply with 6volts, like your dash gauges (fuel & temp). You can buy voltage reducers for them (or use a 7.2v zener diode for each gauge). Believe it or not, even modern cars still use 6volt dash gauges. You can get a Mustang dash voltage reducer at any junk yard or dealership.

Some parts need to be changed: Horns, Horn relay, Starter Relay, Light Bulbs (including headlights), Flasher unit, Heater Motor, Radio, and battery. Clocks do fine on 12v. If your starter is in good shape, it will work just fine on 12volts. In fact, it will start your car sooner, so it won’t be on as long. Add a coil resistor (ballast resistor), purchased in any auto parts store. (I think they’re about 4Ω and around 20watts.)

Many cars have been successfully converted to 12volt. EBay offers guides for ten bucks, but they also have a FREE guide:

http://reviews.ebay.com/6-to-12-Volt-Conversion-1955-Ford_W0QQugidZ10000000001571127

It pertains to a Ford, but that doesn’t matter, all the general rules still apply. If you have any questions, let me know. Hope this helps - Dave Dare

[serb]

Following up on Dave's link to Harbor Freight:

I have been looking for a charger/jumper for a 6 volt. I called the local HF store and the $35.00 charger/starter is on sale for $30.00. It needs to be plugged in for the jumper to work, so hopefully you are not way out in the woods or someplace you shouldn't be when you might need it.

stevo

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JohnD1956</div><div class="ubbcode-body">So is this change truly necessary?

...a properly operating 6 volt system really ought to be enough for your car, with the exception of a modern stereo.</div></div> I don't mean to hijack galenmd's thread, but he mentioned several things he would like to incorporate in his conversion. Converting to 12volts will give him the freedom to run whatever he wants.

None of this is necessary to you, John. But every owner has different needs and situations. For the past fifty years, ALL the manufacturers universally adopted the 12volt, neg. ground system as 'standard,' and none ever switched back. With all the fancy stuff cars power today, it is still a great system. So, did they make a mistake? No. The 6volt system was adaquate, but just barely. Come on, 210-watts aint enough for spit. A Harley delivers more than that.

Did you ever try to find a 6volt power inverter (to run 115vac)? Good luck; 6volt isn't 'standard.' I use my 12volt 300watt on long trips to run my laptop & GPS. Want a great trouble light? Just unhook the one in your garage and plug it into the inverter. Who ever heard of those things back in the day? There are scores of accessories (like those tire inflators that plug into the cigar lighter), that simply didn't exist back then. galenmd mentioned Blue Tooth, another fine example.

If your battery only had three caps, who would know it's a 12volt system? These old cars are meant for us to enjoy. Driving mine is always a pleasure, and I do that whenever I can. It doesn't just sit in a garage, and I don't spend all my time just waxing it. There are hundreds of classic cars within five miles of here, and our families get together in different places all summer long, every year. OMG! Sometimes it RAINS, too!

[JohnD1956]

I guess I should have just shut my mouth, but Galen said he was considering this modification, so I thought he was looking for relative comments from both sides of the issue. Because I didn't (shut my mouth)I would like to qualify something: My posts always contain my own opinion.

And in my opinion a 12 volt conversion will impact the greatest value of a 49 Super convertible, which I believe would be it's adherence to it's original design. I think I did see a 12 volt battery with three caps one time, so if one exists, that would not give away this proposed change. But isn't that a custom battery? If so I would imagine it is not as in-expensive as an ordinary 12 volt battery, which sort of negates that advantage to this conversion plan. Meanwhile the one wire alternator certainly won't be difficult for anyone to see.

Meantime, based on my experience driving my 56 in the sun, rain, and darkness, to Michigan and Ohio several times over the years (plus a lot more within NY State too), I feel confident mentioning that an original 49 windshield will cause much more trouble seeing the road regardless of the increased illumination from 2 new 12 volt lights. In addition, based on further experience, I would mention that if this 12volt conversion was to occur before installation of the new wiring harness, I would consider not installing halogen headlight bulbs due to the extra draw on the wiring. NAPA still has conventional bulbs available.

But it's not my car. It's only my own opinion that the greatest value of this car is in originality. And just in case you think I am a die-hard purist, let it be known that my 56 Super does indeed have radial tires which I most definitely recommend. It also has hardened valve guide seats which cost me a measly $300 to have put in way back in 1988, just to later find out our old Buicks don't need them in the first place.

I now adhere to the old time adage "don't fix what ain't broke", and I still find a lot of stuff to be fixed. However,it's up to each other person to follow the plan that suits them, and I fully respect everyones choice in that. In other words, if Galen does do the conversion, it's his choice and it won't cause me to lie awake at night.

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JohnD1956</div><div class="ubbcode-body">I think I did see a 12 volt battery with three caps one time,...

In addition, based on further experience, I would mention that if this 12volt conversion was to occur before installation of the new wiring harness, I would consider not installing halogen headlight bulbs due to the extra draw on the wiring.</div></div> John, 12v batteries are smaller. You can put one inside a 'mock-up' 6v case by extending the posts. Restorers are good at this kind of stuff.

Regarding the lights, your experience should show that original 6volt wiring is TWICE as big as it needs to be for the 12v coversion. That's part of the beauty. All original wiring can be used safely, even if you add more load. Fuse sizes are designed to protect the wire. They can remain the same because the wire sizes remains the same.

[Guest galenmd]

Guys. This is great stuff. I really appreciate the lively debate.

As far as originality is concerned, I am mostly concerned about looks. I will likely never "show" this car, but want to drive it often if possible. <span style="font-style: italic">By the way, my windshield is sparkling clear.</span>

Besides, if I do the conversion and decide to sell the car, can't it be easily converted back by the next owner (especially if I save all the parts)?

Dave, on your link, you state that the horns need to be replaced. Why not a resistor for those too?

[Guest simplyconnected]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: galenmd</div><div class="ubbcode-body">Why not a resistor for those too?</div></div> I guess you could do a resistor, but it would be a BIG one. Horns work by make/break contacts that energize two coils. Would you try something for me? Put both 6volt horns in series, and see if they work, ok. Wait a minute, I have a set. I'll try it tomorrow. There's no way you can damage them when hooked in series, but the volume might be low because they make/break at different frequencies. Maybe they will resonate at multiples, like the third, fifth, or seventh note from low. We'll see.

Everyone I know bought old Mustang horns (the real big ones from the '60's). Some guys tried using 12-volts on their 6-volt horns and they worked, but the pitch was too high.

Converting back to 6 volts would be VERY easy. You will damage nothing at all in your conversion. Actually, you could do a dual voltage deal by putting a 6-volt battery in the trunk, and just run a few accessories off that battery, like the stock radio and any motors you have (power windows, seat, heater fan). They can share a common negative to chassis without any interferance, and the 12volt battery can trickle-charge the 6volt using those same 7.2v zeners (@ 2amps), we talked about earlier.

I don't mean to complicate this. It is an easy conversion, and resistors can do the job on many components. After all, isn't that how we get different heater blower speeds? GM screws that resistor right inside the heater duct with three stabs sticking out for a receptacle going to a switch.

Something very important comes to mind. If you need to idle for long periods, you can now use an electric radiator fan, and say bye-bye to overheating. It will increase hp & save gas, too. - Dave

[Guest galenmd]

Well, I went to start my Buick this morning and guess what? The battery is completely dead again! This time, I forgot to disconnect the battery overnight.

I can't imagine I had 2 bad batteries.

I don't have a charger, but ordered one from the site recommended above. I will likely have by Tuesday. There are some frayed wires coming off the generator that I sealed with heat resistant fiberglass tape. Perhaps they are broken internally and not charging the battery?

I hope this time, the battery accepts a charge. Last time, it would not.

[Jim Cannon]

Galen-

This is a high end car so it should have an ammeter. You need to get into the habit of looking at it, to help you diagnose your charging system. Modern cars have dropped the ammeter because our alternator does a good job charging at any speed. But it was there on the old cars to help you, the driver, prevent a problem like a dead battery (or boiling your battery dry from a stuck voltage regulator putting out too much current all the time).

After starting the engine and when driving at any reasonable speed, the ammeter should start out showing a pretty good charge and then the amount of charge should slowly go down with time as the battery gets charged up. If your battery is low then it will stay on a good charge level for a while but then should come down toward zero. If it does not show some current flowing to the battery after starting, at RPM over about 1200, then you're not charging your battery. Suspect generator and/or voltage regulator. Both are easily diagnosed and fixed.

With a generator, at idle and with no load it should only show the slightest discharge. With headlights on at idle, it is normal for it to show a pretty good discharge. But as soon as you get the RPM up again, the charge should jump back up positive for a few minutes and then taper back toward zero.

Guys who grew up driving cars with generators did this all without thinking too much about it. It was normal, like watching the temperature gauge or oil pressure gauge.

If you keep having dead batteries overnight unless you disconnect the ground, I suspect a parasitic current draw somewhere in your harness. Again, pretty easy to find (harder to fix).

[serb]

I'd also be looking to make sure the trunk or glove box light(s) is/are not on constantly. Are you leaving the radio on all night. You had to shut them off in those days.

Stevo

[Guest galenmd]

The ammeter always seemed to perform normally, showing a positive charge while driving. I am assuming this charge is making it to the battery.

I can't tell if the radio is on because it is non-functional. I went to open up the grill and piles of dust fell out. Quite comical actually. There are no lights on.

There has got to be a draw somewhere. I should get an electrical guy around here (in L.A. if anyone knows one) if I can't figure it out myself. The wires are crumbling. I am resigned to ordering a new harness that the car needs anyway. Darn expensive though.

Does anybody have a preferance for YNZ or RIWire (or anybody else)?

[Guest simplyconnected]

Do you have just three wires, from your generator to your regulator? Doesn't your generator have posts that accept ring terminals? Seems to me, you can make your own harness for under ten bucks, using good flexible copper wires.

[Guest galenmd]

Yeah, I can fix this one area, but there are plenty of other spots that are withering away. All the wiring is stiff and crumbling. I was advised by several people to do an electrical overhaul to prevent a major fire. I think it is time to do it.

By the way, what gauge wire do you recommend?

Also, what is the deal with a 6 to 12 volt inverter? These don't make sense to me. If this is a feasible option, then I could use one of these to power my stereo and phone charger. Somehow, I can't believe this could work.

[Guest simplyconnected]

Take each harness, one at a time. With proper terminals, there is no reason you can't make them yourself (and save lots of money). Being a restorer, I enjoy taking my time and making this stuff. If you don't have time, buy it and have someone else install it (as do most enthusiasts).

A 6-volt generator outputs about 35-amps. #10 wire will safely carry that, in free air (not inside pipe). I would buy #12AWG (American Wire Gauge) and #10AWG in stranded copper. You can buy good automotive wire at any auto parts store. Home Depot has THHN (thermalplastic insulation) which is great wire, but is stiff and wants to go its own way like spaghetti. MTW (machine tool & automotive wire) insulation is softer and more compliant. Contractors like THHN because you can get more of it in a pipe (insulation is thinner, and rated for 600V).

Buy small rolls, but get different colors. From the generator to the regulator is only a few feet. If you think you will do more harnesses, get larger spools.

Start at the generator, crimp proper terminals on the ends, and tape the wire into a harness. Then route it in the exact way the original went. When you get to the regulator, terminate that last. So, #10AWG for the 'A'rmature and Ground wires, and #12AWG for the 'F'ield. The other wire, 'B' on the regulator, goes to battery (#10AWG).

Inverters: They are like computer power supplies. They need cooling, and you don't get something for nothing. I have not seen one which goes from 6-volts to 12-volts, but I'm sure they must exist. They will be very expensive, and like all power supplies, they are rated in watts. Add-up your demand (Ex: ~50watt stereo & ~15watt phone cord = 65-watts) Then, double it. A 150watt power supply will work just fine. The feed for this is--150w/5v = 25amps. #10AWG will carry 30a safely (fuse #10 wire at 30a). This is a close example. If your demand is much more, you need to resize the inverter and wire.

Harbor Freight has lots of stores in CA:

http://www.harborfreightusa.com/usa/storelocator/locationsByState.do?state=CA

While you're there, buy a decent multi-meter:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=37772

and a terminal kit:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45015

Sometimes the 'dollar store' has terminal crimpers. Hope this helps - Dave Dare

[Guest galenmd]

Thanks, Dave. The effort and time you put into your responses is phenomenal and appreciated. I will refer to your posts often.

[Guest galenmd]

Here is a 6 to 12 Volt converter with enough power. Quite pricey.

http://www.powerstream.com/dc6-12.htm

[Guest simplyconnected]

OMG! The $150 model (PST-SR700-6) requires positive ground and it only outputs 125-watts continuous.

The second one (PSTC-0624012) is $375.

Neither can be mounted under the hood, or in a hot trunk. That only leaves the dash/cowl/kick panel area. Neither one can run a motor, and they have a fan (which sounds like a computer).

Converting to 12-volts will be far cheaper, then you can run anything you want, (like every other 12-volt car).

I forgot to mention, if your radio isn't working, disconnect the fuse. It's probably an in-line, right next to the radio. That way the tubes can't suck your battery down when your car is off. Glad I can help. - Dave

[Guest galenmd]

I guess if my heater doesn't work, I can install this under the dash to keep me warm!

There are others out there, but with very low wattage. I agree that it would be better to convert to 12-volt.

I think I found the battery drain. There was a rear window switch disconnected while accessing the rear panels. They were not taped and all 3 wire contacts were crammed together.

I am waiting for my battery charger to arrive from Harbor Freight. It should be here today. The last battery that drained would not accept a charge. If the battery is completely drained, does it become damaged? Is there some prep or other special thing to do to recharge a dead battery? I am using the Interstate Workaholic 2E-VHD.

[Guest simplyconnected]

I have had 'limited' success reviving dead batteries. It helps to understand 'plate sponge' and the sulfation process:

http://www.canadus.com/pages/page.asp?s=3510

A new battery needs to develop 'lead sponge'. I've seen brand new batteries fail to start a new car, so they change batteries, put the 'bad' one off to the side, and slowly charge it. After a couple days that battery will properly form its sponge, and be new again. Strange but true.

Old batteries tend to cover their sponge with sulfation,if they are not fully charged or left discharged. Pieces of lead fall to the bottom of each cell, eventually shorting the plates. Vibration from running the car promotes this short.

You might get lucky if you gingerly, and s-l-o-w-l-y charge your dead battery. The longer it has been left discharged, the more time it needs to form its sponge, and break through the sulfation, again. Fast charging will certainly kill it for good.

[Guest galenmd]

Update:

I received my charger and could not get the battery to draw anything from it. I left it on a slow charge overnight without anything.

There is an Interstate battery dealer close to me. I took it over now and he had the same problem. He then ran the charger in series through a 12 volt battery and immediately got it to accept the charge. We won't know until tomorrow whether it works. If not, it is still under warranty, I just won't be able to drive my baby for awhile. It will give me time to work on other stuff.

[RocketDude]

There are companies that make 6V alternators that solve all of the problems without the down side. The put out a constant 7.5 volts. There is even one company that makes a 6V alternator that fits into your generatorcase, so it looks original. It's not cheap, but what have you found in this hobby that is?

[Guest galenmd]

RocketDude,

Thanks for the info. I think my generator is functioning properly, so I will only change it if I go to 12V. Do you have the name of this company? Do they make a 12V alternator that fits into the generator case? Now that would be interesting. It would be nice to keep everything looking original, but functioning at 12V.

[RocketDude]

http://www.powermastermotorsports.com/powergen.html

How is this for totally trick..?

Here is another 6V alternator, but this one looks like an alternator.... Ugh...!!http://www.alternatorparts.com/6_volt_alternators_&_kits.htm