For installing a starter in a pre-19 car that will have a battery located in the rear, what size cable should be run for 6 volt and what size for 12 volt?
6 or 12 volt? I understand 6 volt will power the starter fine when properly cabled and installed and I have no problems with 6 volt in general. My reasons for considering 12 volts are availability of batteries, the brake light is 12 volts, the ability to use a simple charger off the magneto like the one John Reagan sells, and I probably have adequate size welding cable already. I like the thought of 6 volt for not beating the starter. Since the starter is not correct for pre19 I don't see that as part of the discussion.
Orscheln, TSC, Fleet & Farm, whatever is in your part of the country, any farm supply will have six volt batteries.
He Steve. I can find them, just not quite as easy at a reasonable price because I'm pretty much limited to auto parts stores.... they're just not as common around here. The on board charging is really the biggest concern, not beating up the starter is the biggest plus. And of course the question on cable size.....
I would run a #1 cable for the 6v battery. That is what I use on my car.
The correct size cable for a 6V system is 1/0. Most part suppliers are selling 12V 2 gauge cable which is incorrect for the 6V system. Some sell the larger 1/0 cable at a premium as the "original" style cable. The only way to be sure of what you're getting is to measure it.
If you don't find 1/0 cable at your modern auto parts chain store, try a welding supply. You can buy the right lengths to fit, and the terminals, and solder them together yourself. The catalogue prices seem pretty high to me. I'd rather spend that money on something I can't easily do myself.
I've probably got the cable here, I used to have a bunch of welding cable scraps up to 2/0.
What about charging? I really don't want to hang something off the side of the engine......it looks way to modern even to a casual observer. The thought would be to use this as an occasional starter (I killed it during a parade or in an intersection).. I'm going through my '15 engine so I put a ring gear in it, and I've got a couple of starters and hogs heads. I think the Fun Projects charger would work for 12v, but I don't know if there is an equivalent for 6 volts. Right now I figure if I use 6volt I have to pull it and charge it. Any idea how often, as in how many starts, approximately? For this purpose how does 12v compare?
Talk to John Regan before you give up on the Fun Projects idea.
If you're going to run 12 V, I would suggest having the starter converted to 12 V.
There's no reason you can't charge a 6V battery offn the magneto with a suitable charger.
If you use a 12V battery, you need to use smaller size cable. The smaller cable has more internal resistance to current flow. The result is a voltage drop and the starter does not slam in as it would with a very large gauge wire.
I`ve been there, and done that! It`s all in amps, when you use a 12v battery use 12v starter,or it`s hard on the bendex and starter ring. If you have to use a 6v starter use 12v standard cables. Those cables are smaller than 6v cables, 12v cables are smaller and will slow the amps down and will slow the starter speed down, and be easy on the starter ring, and bendex. Hope this heips!
Gary, a battery will maintain sufficient charge for "occasional starts" for a surprisingly long time, even without on-board charging. And, you certainly don't have to pull the battery for charging — lift the floorboards or seat cushion and hook up the charger directly, or connect the charger under the hood to the terminal strip and an engine ground. If neither of these is practical given your location and wiring setup, run a pigtailed modular connector from the battery to a convenient point and go from there.
No. 1 cable is the right size, but 1/0 will add a little kick to the starter, especially when you put the battery way back there under the rear seat.
Get 1/0 (pronounced, "one ought", from a welding supply but order the terminals from an auto parts store. Ask for 3/8" terminals, that's the bolt hole size. You will need to trim a little off the sides around the cable as welding cable is slightly larger than automotive cable. But welding cable has more/smaller strands and is very flexable.
Put the terminals between two pieces of wood in your vice and heat the terminals with a torch and flow solder into it and warm the cable end at the same time and quickly jam the cable into the solder while it is still liquid.
Have some water handy to pour on the area.
I always buy my battery cable from my local welding supply store. I use #1 cable and purchase copper lugs and solder them to the cable. You can also buy a solder on battery terminal and again solder it on.
The welding cable is a fine stand cable with minimal resistance that will deliver the maximum current to the starter, which is the reason to use the best cable and connections.
Most parts store cables today are made in china and are not the quality that US made welding cable, therefore more resistance and less starting power.
Do it right the 1st time and you will not be unhappy with the results.
I'm pretty sure I have 3/8" Thomas and Betts connectors and the correct crimping tool, we used these for battery installations in radio sites.
Something that's new to me is the mention of converting the starter to 12 volts. What is involved with that, who does it, what does it cost, and how do I tell if the starters I have were converted? At least one of my starts was run by my dad at 12volts,vbut he's been gone 13 years now so there's nobody to ask. But I'm sure if there is a conversion process it should be discernible.
Most 12 volt systems use the original 6 volt starters. 12 volt starters are available for model t Fords. That larger welding cable described above is OK for the 12 Volt starters or the 6 volt systems. An original 6 volt starter on a "12 Volt battery" needs the smaller cable so it will not damage the ring gear and bendix.
DO IT RIGHT THE FIRST TIME AND YOU WILL NOT BE UNHAPPY WITH THE RESULTS.
Hi Gary, If I were making the conversion I would choose 6V because 6V starters are plentiful, and more period correct. But that is a choice you can make later. First I would wire it using 1/0 welding cable, then your 6V/12V options are open. Using A high resistance wire to reduce "starter shock" is in my mind foolish. High resistance Wire (smaller size) reduces current flow to the starter but dissipates that reduced current by turning it into heat. This will put a heavy load on all the connections, starter switch, etc. which should be avoided.
Charging off the Mag. is limited and would probably not provide enough recovery for repeated starter use, however daily external charging is a viable option here.
I use LEDs for my tail/stop light and 6v versions are available. For a long time on my armstrong '16, I ran my LED stop/tail lights off Mag voltage only, by adding a resistor in series with the lights, however the stop light became very dim at slower engine speeds (like when stopping), so I added a smaLL 12V Gel cell battery, charging it off the Mag. to solve that problem.
Either option you chose will work, hopefully these thoughts will help.
6 volt battery cables should be no smaller than 00 guage. Commonly referred to as 2/0 guage.
John, I am glad you understand why I said to use starter wire smaller than the standard 6 volt type. The size available for 12 volts systems is small enough. I did not say to use some tiny wire that will smoke the first time you hit the starter.
In the electrical world there is a formula for calculating current. "Current equals voltage divided by resistance" Wire has some internal resistance and the idea is to use slightly smaller wire which will have more resistance to the higher 12 volts. This "Slightly" limits the current but does on get hot as you implied.
I think the reason a lot of folks switch to 12 volts is to get a little faster starting, but they do not want to damage the bendix and other starter parts.
If you want to use that very large wire, put on a 12 volts starter that is built for 12 volts or get yours rewired as Royce showed.
(Message edited by Willie in Houston on September 29, 2014)
Willie and John... I am familiar with PIE, and The relationship with current and heat..... The power has gotta go somewhere! I'd much prefer to use the correct size cable to match the application and get the matching battery and starter. I will see how the starters I have are wired. One I am sure is 6volt, but the one my dad used when he could no longer crank could be either..... If it's 12 volt I'll use cable size for 6 regardless if I have it, but a 12volt battery. If I have to start from scratch I'll probably stay 6.
What is the thought on grounding size? I plan on running a ground cable to the rear corner bolt of the hogshead.
Here we go again with these cable sizes
1ga, (0) (00) (000) (0000) for 6v cables marine, welding, house wiring cables, why not use a solid copper rod???..
maybe they need to change this forum to a discussion index.These has been previous discussed on a monthly basis. cables, distributors, trailers, coils, mags,
Willie is correct. With 12 volt batteries in a Model T you should use the smallest diameter and longest length battery cables you can find at the local part store. The resistance is transformed into heat, but the heat is distributed over the length of the cable. You won't feel any perceptible heat change from operating the starter a few seconds.
Thank you for your constructive input Robert. It sounds like you read the initial post and all of the questions.
Royce. When we build battery plants for our equipment sites we build the source battery plant based on anticipated load, and cable is sized for minimum voltage drop. The only reason we step down cable size when we get closer to the equipment is to reduce the cost and still meet the design requirements ( those are really big cables). Proper sizing as I've been tought was based on determining the minimum size for the application, and there is no issue being a step over. I am trying to understand the smallest size and longest length suggestion because it does add resistance and therefore voltage drop and increased heat (I understand that short bumps of the starter are not going to melt my insulation if I run #1 vs 1/0). Is your suggestion strictly for an application using a 6v starter with a 12 v battery? Or all 12 v applications? I will build my cables, so I don't need to rely on the parts store for size or length. If you have a chance please explain your suggestion a bit more. I don't want to redo this.... Short cuts aren't worth it. I think I understand what you and Willie are saying and why, I want to be sure.
(Message edited by Modeltbarn on September 29, 2014)
For the guys attending Carlisle / Hershey car shows this week and next. RJ&L Automotive Fasteners & Vintage Wiring Supplies will be selling bulk cotton covered battery cables from 2ga-2/0 along with the tin coated brass battery terminals, spark plug wires, asphalt loom, 14ga, 12ga 10ga cotton covered braided primary wires in different colors with tracers.
Hershey CN 61-64
Yes, I use a long, small diameter pair of 12 volt cables as a resistor to intentionally limit current to the starter from the 12 volt battery. I think the ones I have found at the local Pep Boys were 10 feet long each, and 4 guage.
Here's something that would work:
I had a hard starting Model T I have been working on for a year. After reading many posts here, I cleaned EVERY contact from battery to starter and had a starter shop make a 1/0 cable for me starts fine on 6 volts !
Robert, unfortunately, the guy making all the 12 Volt 2 Gauge Model T cables for every parts supplier never reads this Forum.
One supplier advertises 2/0 Gauge cables and sell 2 Gauge cables. They must still be selling!
A solid copper conductor does not carry as much current as a stranded copper cable given equal diameter. Current travels on the surface of a conductor. More strands = more surface area = more current capacity.
Thanks Royce, I was just going to post that info. Now I am going to put this in the mix, some where I read and was told that battery cables should be crimped not soldered.
Royce, you are not correct.
DC current is distributed evenly throughout the cable. Once the current starts changing then the current gradually moves to the outer edge of the wire, the so-called "skin effect". It is only significant at radio frequencies and above. This was discovery by a German engineer (Meetz?) who then developed the multi-strand wire for radio coils.
This was my business for 30 years and I an certain of my facts...