MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - BATTERY CABLES

I want to replace the battery cables in my 1600 (single 12 volt battery). Is there any recommended gauge for the cable. The original ones would appear to be a 1 gauge from the thickness of the cable ??? Any suggestions ??
Michael Hosier

When I redid my 58 I used regular 12 volt cables from the local auto parts store. Never had any issues since. 6 volt cables are heavier than 12 volt but what the size the originals were I don't know. Good luck.
Bill Haglan

Hi Michael. I dont know what guage of wire you should use. I have heard of people using 2 stock cables, so I guess one cable that is twice as thick would work fine. This should effectively half the electrical resistance. I also hear that welding cable is excellent for replacement battery cables, although you have to find and solder on appropriate ends. This (I would think) should (somewhat) increase the cranking speed and efficiency of your starter motor. Please let me know what you end up using, because my cable needs to be replaced also. Cheers! Glenn
Glenn

Remember that current flow is affected by all cables in the circuit, from the battery to starter through the switch, between batteries (twin 6 Volt batteries), and the one usually forgotten across the front engine mounting.

Mick
Mick Anderson

Resistance varies inversly with the square of the diameter, so you don't need to go twice as thick to get half the resistance and half the voltage drop. Increasing the wire diameter by 1.41 times, will cut the voltage drop in half.

As for the required wire size, mine measures about 0.255 inches which is 2AWG. I don't know how many amps the starter requires, but this page has a calculator that you can plug in wire size, wire length, and amps, and it will tell you how many volts will be lost in the wire. Putting in 10 feet or wire, and 300 amps, it says that 2AWG will drop 1.1 volts, and 0AWG will drop 0.7 volts.

http://www.powerstream.com/Wire_Size.htm

Jeff
Jeff Schultz

I used 1 ga. that I got from my local NAPA store. The long one I made myself at work out of 1 ga.
NAPA only went up to about 80" long. You could also check with some of the semi truck repair shops, many make their own cables.
Jim.
Jim Jensen

Michael

Your local welding supply should be able to provide quality wire of the proper size and length. IF I remember correctly I used 0 gauge when I replaced the cable many years ago. Cost and size differences compared to 1 gauge are very small and give you a peace of mind.

To do it up "right" you should solder the fittings on each end to avoid potential corrosion problems that have been mentioned on at least one of the BBSs recently.

FWIW

Larry
Larry Hallanger

Hi Folks. As an addition to Larry's statements in the last posting: When soldering new connectors onto battery cables, be sure to use Rosin core solder only! Rosin core solder is specially formulated for electrical wiring work. If you use "regular" solder (usually used for plumbing and sheet metal) It could contain an acid flux that will eat, or corrode your newly soldered battery cables! Why is it that NOTHING is ever as simple as it first seems?
Cheers! Glenn
Glenn

And after you finish soldering as Glenn describes, seal the joint between the cable and the connector with something. Corrosion of the copper conductor that lies hidden under both the brass connector's shell and the vinyl/rubber cable insulation can cause destruction which will result in less actual current conducting strands of the wire itself to carry your electrical system's load, or to charge your battery.

I have used liquid electrical tape (comes in applicator brush capped cans ~ you can get it cheap at Harbor Freight) or the stretchy self-fusing silicone tape to seal the joint. Once the sealant is applied, you might also want to use a bit of heat shrink tubing to hold the sealants in place and provide some protection from abrasion and other forms of wear and tear. May sound like overkill, and perhaps it is, but 15 yrs later since doing this, cables done this way have remained good. Good luck!

Bob Muenchausen

Bob

Maybe a short "How to make a battery cable" article would be a useful addition to your web site?

Larry
Larry Hallanger

Or to Barney's. I should do that tho as it applies to all cars and all MGs. Thanks for the good idea, Larry! :-)
Bob Muenchausen

This thread was discussed between 23/01/2005 and 27/01/2005

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.