Technical 6 V jump start

I have a car still with a 6v system. And I'd like to get a portable jump starter in case I break down and need a jump start (again). Last time I had to be towed since they can't jump start a 6v with a 12v unit.
I been looking for a 6v/12v jump starter (cause I also have an antique 12V Model A) and evidently they don't make a 6v. Anyone know who does?

If not as an alternate I thought i could just get a spare battery, keep it fully charged and take it whenever I take to the road. Got any thoughts? Any downside to that idea?

 

Sixty years ago I jumped many a 6V car with a 12V car. Guess it will still work although new cars have computers. If you just use a 12V battery you should be ok just don't grind the 6V the starter

 

and make sure the lights, radio, etc are turned off!

 

I Jumped my 6v cars many times with 12v. I only touched the 12v briefly, did not leave cable clamped on..I don't know if this good but it never hurt anything. The battery in my modern truck is 4 years old. I carry a new battery and cables.

 

or get someone to "bump" you with another car. Ever notice how the bumpers on unrestored old cars are all scraped up?

 

I had an o/t hatch back winter beater years ago I could bump start myself , door open quick push jump in and jam it in 3rd and away I would go .

$65 bucks for a starter ?!?!?!?! No way man

but yeah 12 volts to jump start won’t harm nothing .

 

A lot of early cars are 6 volt positive ground, so if you jump it with 12 volt negative ground relays etc go blewy

 

Always put the positive to positive and negative to negative no matter what the ground. 12 volts will not hurt the starter and the starter doesn’t care about polarity , but batteries do. I have converted many six volt tractors to 12 volt and kept the six volt starter, with no problem!





Bones

 

^^^^^^Same here with the tractors, Farmall H and M's also Ford Y blocks with Ford alternators and voltage regulators.

 

Thanks for all those great "tips" But I'm leery about jumping a 6 v with a 12v cause the gages and ignition coil could be damaged and the battery could be damaged, they say.
But here's the story I figured Idemail Schumacher (prob the leader in batery chargers & jumpers). So I sent an email ask about a 6 v jumper. They sent me model # SC 1400 which is NOT a jumper but only a charger. So i go back and say no I WANT A PORTABLE 6V jumper so they send me a link to a 85 pound shop model. I then find 3 dual volt 6/12 jump starter & charger. WHY DIDN'T SCHMAKER EVEN KNOW THEY MAKE THEM? btw you can find them on Amazon, EBAY and Home Depot.

 

Customer service side usually knows nothing about the technical side of a company/product.
I have an SC1307 model(85A) and it is a 6V/12V unit. Didn't realize this charger was 6V capable until I had it at home. Don't think it was mentioned on the outside of the box.

As for boost, most new digital boost boxes(carry or plug in) will ONLY provide power once it detects a draw from cranking and when you stop cranking it cuts out. So no worries of damage to your gauges and what not. Voltage drop is gonna be high when cranking anyway(and starting circuit usually divorces non essential components, that's why your radio/fan cut out when cranking) so no worries of over voltage issues.
Older chargers used to have the manual boost/jump switch and they usually had a warning of not to leave on for more than s seconds when not boost/jumping.

 

Don't let what "they say" keep you from enjoying your 6v ride. I am 77yrs. old and have been jumping .....everything....Model A's.....tractors.....lawn mowers.....Indians.....Willys Jeeps.....etc. etc. I have always judiciously used 12v batteries to jump. Right now I have a spare 12v that can be put in a battery box or tool bag. You might want to fabricate battery connections that can bolt to jumper battery and car without using jumper cables. These are available in all parts stores. Lastly......the secret to great 6v performance is good ground and positive cables of 0 or 00 gauge. Ideally ground cable end going directly to a bolt holding the starter onto the bellhousing. Give the amperage and voltage an easy, clear path. Have fun.

 

I'll be that dude....

It really simplifies things to convert it to 12V. You can keep the starter and all. As had been said, it's been done many times on tractors. I've converted a few Farmalls from 6V positive ground to 12V negative ground with just an alternator, light bulbs, and an ignition coil.

You'd need a 12 to 6 volt reducer for gauges, replace the coil with a 12V one and replace light bulbs. That's pretty much it, unless you have a radio.

 

Unless the 6 volt battery is dead, you can just jump start the starter, that way you won't hurt anything in the car.

 

Something else to consider.
It's true a 6v can be jumped by a 12v but can it still be safety done if more modern 6v bits have been added? Thinking 6v regulator/radio/ect. Many or these 6v bits have circuit boards that may or may not be friendly to 12v. It's something to consider because I don't know having always just switched to 12v.

 

That mysterious "they" sure gets a lot of play. Their advice seems to override real people.

Ben