GPS and 6 volt cars

[Matt Harwood]

Has anyone used their portable GPS in their vintage 6-volt car? I know it will work on battery power, but with the big screen mine has the batteries don't last all that long. I can wire up a cigarette lighter outlet, but does anyone know if the GPS will charge using the 6 volt system? I believe the USB connection the GPS uses is rated at only 5 volts, so the step-down transformer in the charger should (theoretically) be able to charge it no matter what the source, yes?

Has anyone tried this? Disastrous or no effect?

[ply33]

Most portable automotive GPS units and newer cellphones can be charged over a USB port. USB ports are 5v DC power. So there is more than enough voltage in a 6v car to charge and run the units. Two issues: 6v is not 5v and you probably don't want to put too much voltage in. Convention for USB power is negative ground.

My solution is posted at Plymouth: First Decade - Cell Phone Charger

Used it for the last half of last summer and seems to work okay even though the voltage regulator I used likes a bit higher input voltage.

[rsb]

I bought a 6V to 12V step-up converter and wired it to a cigarette lighter jack. The thing is freakin' awesome. 6-8 amps at 13.6VDC depending on the polarity of your car. No-load current is less than 3mA so it can be left on full time or can be wired through its own relay to trigger with the car's ignition system. It will operate with as little as 4 volts. It's well filtered so there's no switching noise when powering radio receivers. Zero ripple. By far the best inverter I have tried yet and I have tried quite a few.

6 Volt to 12 Volt Converter

I have no affiliation with the above, just giving an opinion based on my experience.

Regards,

Ron

[Jay Wolf]

Has anyone used their portable GPS in their vintage 6-volt car? I know it will work on battery power, but with the big screen mine has the batteries don't last all that long. I can wire up a cigarette lighter outlet, but does anyone know if the GPS will charge using the 6 volt system? I believe the USB connection the GPS uses is rated at only 5 volts, so the step-down transformer in the charger should (theoretically) be able to charge it no matter what the source, yes?

Has anyone tried this? Disastrous or no effect?

I use one in my 55 Thunderbird often, the problem with using the 6 volt is the generator voltage reg doesn't keep a very good 6 volt. 4-8volts not good on modern electronics plus you have the ground issue. I used a 6 volt positive ground to 12 volt neg ground adapter and it works very well.

[Steve Braverman]

I use one of these. It also keeps the kids' DVD player running for a few hours and charges cell phones.

Amazon.com: Roadpro PORTABLE POWER SUPPLY 12V MPSL-600: Sports & Outdoors

[Rawja]

I believe the USB connection the GPS uses is rated at only 5 volts, so the step-down transformer in the charger should (theoretically) be able to charge it no matter what the source, yes?

No the transformer within doesn't modulate based on input, it's operating parameters are fixed.

Go the route suggested above to give the charger a proper 12V supply.

[Grimy]

An arrangement for transferring a GPS among multiple 6V cars:

Because I have multiple vintage cars, all 6V and all but two with positive ground (and three of which are 1920s cars without 6V lighter sockets), I use a sealed 12V gate-opening battery ($18 at Lowe's online, $35 at Radio Shack on the shelf) as a power supply for the GPS. I carry the battery in a small box or in a plastic Folger's coffee can on the front seat floor behind the gearshift lever. I used a lighter socket adapter from Radio Shack which had alligator clips for intended use with an underhood battery. These clips will work but are too large and awkward, so I eventually cut those alligator clips off and replaced them with smaller push-on spade terminals from Radio Shack.

I've used the GPS continually on up to 5-day, 500-mile tours for Teens and Twenties cars without having to recharge the battery on the road. After 5 days, the battery did get down to about 12.1 volts by the end of the trips, but the GPS (2007-vintage large-screen Garmin 800) still worked fine.

A cheap, easy solution for transferring GPS among several 6V cars...

[Guest De Soto Frank]

Matt - better be careful running GPS on 6-volts: you're liable to get pre-1955 directions !!!!

[Jim Bollman]

Because I have multiple vintage cars, all 6V and all but two with positive ground (and three of which are 1920s cars without 6V lighter sockets), I use a sealed 12V gate-opening battery ($18 at Lowe's online, $35 at Radio Shack on the shelf) as a power supply for the GPS. I carry the battery in a small box or in a plastic Folger's coffee can on the front seat floor behind the gearshift lever. I used a lighter socket adapter from Radio Shack which had alligator clips for intended use with an underhood battery. These clips will work but are too large and awkward, so I eventually cut those alligator clips off and replaced them with smaller push-on spade terminals from Radio Shack.

A cheap, easy solution for transferring GPS among several 6V cars...

Great idea. I have the bigger jumper power packs they sell to do the same thing but making your own allows it to be smaller and made to fit in the spot available.

I also have an Energizer XP8000 power pack that is compact enough to fit in my pocket and will extend the run time on most of my toys that normally charge off USB to get me through the day. I haven't tried it with my new GPS yet, but plan to. It could be tucked into the ash tray and should give me 6-8 hours or more of run time.

[mrspeedyt]

my older gps uses a 12 v cigar lighter plug to recharge. the built in battery pack of my gps is 4v. on my 6v cars I simply clip on a insulated cigar lighter socket with regard to polarity and it recharges fine.

[Rawja]

my older gps uses a 12 v cigar lighter plug to recharge. the built in battery pack of my gps is 4v. on my 6v cars I simply clip on a insulated cigar lighter socket with regard to polarity and it recharges fine.

Thought of that too, but don't know that I'd want to subject an expensive piece of gear to the vagaries of the car's electrics. Prolly worry too much..

[Guest dreld]

I just made a 6v to 12v converter that will run my GPS or charge my cell phone. Maximum draw is 1.25A or it will over heat. I put an in-line 1A fuse just to keep it well below the threshold.

(actually I put in a total of 4 fuses, one at every step of the way. I didn't want to risk anything harming my 1930 car.)

It cost me less than $25 total and works great.

If you have questions, call me and leave a message. I will get back to you, I promise!

2o3 862-8678

Evan Delman

Westchester Region, AACA

Edited April 27, 2013 by dreld (see edit history)

[Guest heftylefty]

It should be possible to find a "brick" type switchmode power supply with a 4 to 8 or so volt input range and 12 volts out.

[Friartuck]

Given the latest generation of GPS units and phones, that run off standard USB 5.0 volts, there is no longer a reason to step up from 6 to 12 volts. The 6 volts to USB 5.0 volts leaves a 1 volt head room which is just enough to use a standard IC regulator. The issue where is that it must include filtering circuitry on both the input side and the regulated output side of the regulator. The ignition noise and ripple noise from the generator that is conducted on the power input may cause the units to malfunction. This was documented by an Australian collector who bought a regulator from a source in Switzerland that did not contain filtering, just the regulator. That source used it on '50's vintage 6 volt cars which has some fltering suppression (which worked OK) as comapred to 1920-1940 vintage electrical system which does not. The Aussie collector tried it on a 1929 Packard and it malfunctioned when he ran the engine. The ideal configuration would be to package the filters, regulator and multiple USB connectors into a single small plastic hobby box. This would power the phone, GPS and any other thing that you might have in mind. The input would be a screw strip on the back. The benefit of this arrangement is that it is more efficient than stepping up to 12 volts (just to have it reduced to USB 5.0 volts). There was supposed to be a company in central NJ that was taking up this solution, but may have lost interest. If someone wanted to experiment, one could buy one of the cigarette lighter USB adapters (seem to be available at drug stores or Radio Shack), add the required filtering and package in a box. Mouser Electronics offers the necessary parts. Just throwing in my $.02 worth here.

Edited April 29, 2013 by Friartuck (see edit history)

[Guest dreld]

Friartuck -

What about those still running a generator? At idle the output will drop. That can harm GPS or Cell phones.

That is why my Step-Up will take between 3v and 10v and give a CLEAN output of 12v. Granted the maximum output is 1.25Amp, but I never run it higher than 1.0 Amp. It all fits in an old 35mm film container.

I can make one that will give over 3Amps out, but it will require Heat Sinks and take up more room.

[Mike Dube]

An arrangement for transferring a GPS among multiple 6V cars:

Because I have multiple vintage cars, all 6V and all but two with positive ground (and three of which are 1920s cars without 6V lighter sockets), I use a sealed 12V gate-opening battery ($18 at Lowe's online, $35 at Radio Shack on the shelf) as a power supply for the GPS. I carry the battery in a small box or in a plastic Folger's coffee can on the front seat floor behind the gearshift lever. I used a lighter socket adapter from Radio Shack which had alligator clips for intended use with an underhood battery. These clips will work but are too large and awkward, so I eventually cut those alligator clips off and replaced them with smaller push-on spade terminals from Radio Shack.

I've used the GPS continually on up to 5-day, 500-mile tours for Teens and Twenties cars without having to recharge the battery on the road. After 5 days, the battery did get down to about 12.1 volts by the end of the trips, but the GPS (2007-vintage large-screen Garmin 800) still worked fine.

A cheap, easy solution for transferring GPS among several 6V cars...

Matt, I do this also, I put the battery in a small plastic box in which I installed a lighter plug. Use it to plug in the cell phone from time to time too. I can bring it to the next meeting if you want a look. It sits behind the freewheeling lever in the Auburn, out of the way.

[Joe Block]

Mike

I am working on building rear compartment air conditioner a copy of Packard did in 39 to 42, I need more like 3 amps to drive the fans, and another unit for the clutch say 5-10 amps again, that say 13 amps at 12 volts, might be high actually, that 26 amp at 6 volts, my regulator is set for 35 amps, do think that enough .