Laptop DC to DC power brick ciggy plug melting

[landyacht318]

I've had this DC to DC 90 watt PWR+ power brick for 2.5 years powering my laptop.

The original ciggy plug quickly proved to be not upto the task, but I wired up a new one and it has been working flawlessly till yesterday, when I replaced that one with yet another.

I just disconnected this one just now as I smelled hot toxic plastic, and found the spring loaded (+) nipple extremely overheated, and the spring loaded 8 amp fuse was melting into the body same as the last one I replaced yesterday

The Ciggy plug receptacle itself quality and is showing no visible corrosion. It is wired to my house fuse panel over 4.5 feet of 10awg. Some other devices share this 10 awg feed, but they, maxed out, are usually no more than 1.5 amps, and during this meltdown were powering only .35 amps of fans, and .12 amps of LED lights

It is the spring loaded (+) nipple which is getting hot enough to burn my fingers passing just 5 to 7 amps.

The ciggy plug receptacle itself is warm, not blisteringly hot like the plug.

I guess I will just bypass the ciggy plug itself, but I am wondering why it now is becoming such an issue when it has been working fine for over 2 years.

Any Ideas?

[landyacht318]

I just put my clamp on meter over one wire just outside the ciggy plug. It bounced from 3.2 to 2.7 amps streaming a surf contest in Hawaii. but the battery is fully charged already.

This DC to DC converter is way more efficient than using my inverter to power the AC brick. Depending on the task being performed, upto 45% more so.

[MEXICOWANDERER]

I might have missed it here so if I play redundant chalk it up to Alzheimer's...

It would pay to measure the wattage. I've run into too many DC DC converters that consume way more power than they should. Like 4 amps needed at 19.5 volts and 11 amperes drawn out of a battery to do it.

[landyacht318]

My powerpoles arrived and I installed one on my schumacher 25 amp charger.

The 12 awg wire barely fits in the crimped portion.
I reutilized the wiring which came with the charger.

It is green under the insulation, so i basically wasted a set of powerpoles as i have no other wire handy to replace it. I did scrape it to shiny copper before crimping.

The connector is not heating up passing 25 amps, which is a huge difference compared to the SAE 12v connectors I employed in the past, and are shown in the following photo for comparison.

[westend]

Mex, I have children with laptops. I've replaced a few sockets on the laptop motherboards. IIRC, I used something like this Coaxial jack. With one laptop, it was necessary to remove a couple bits of plastic extrusion in the interior of the laptop case to accommodate the new jack.

I tried to idiot-proof the power connections by adding an angled male connector with 1/8" inline connectors adjacent (3") to the male jack. This seemed to have solved the connection problems.

[MEXICOWANDERER]

I have been disappointed in the cigarette lighter plugs I have found. STEEL CONTACTS do not belong in a device of this nature. The routing and connecting of wires to plug contacts are a freakin' joke. But making a good plug would be a challenge. Gold plated Beryllium spring copper would have to be encased in a nylon shell. Such a device would last many many years.

Writing of which, my laptop coax power plug is getting looser than a goose and I have nothing to test whether it is the plug or the socket. Which one wears out the most? Getting replacements is going to be a chore and a half. Should I be cautious about what I buy? Sorry to hijack the thread.

[landyacht318]

Sal,

I've made use of those connectors you show. They do heat up, far too much. They are made with 10awg leads too, but the physical connection is just not up to the task of what 10awg can pass.

I'm pretty sure they are called SAE 12v connectors. I'll likely be replacing them all with the powerpoles.

So far, the little teeth I ground onto the ground springs of the ciggy plug are grabbing the receptacle very tightly. The Nipple spring has no chance of backing it out.

I'll still be adding the Blueseas product to the same wall. I can use another 12v plug back there anyway. The ciggy plugs might be a poor connection, but they are convenient requiring one hand only, and not much aligning precision

[Salvo]

Anderson connectors are the way to go. I made a ciggy-to-Anderson converter plug, just in case I want to connect my electronics into a ciggy receptacle.

For years I used the trailer connector seen below. High currents caused that connector to heat up; especially when running the macerator.

Sal

landyacht318 wrote:
I have a certain amount of delegated tinker time for improvements to my interior ergonomics. There have been occasions where I needed the laptop converter, in someone else's vehicle. For that reason I stuck with the standard ciggy plug.

[wa8yxm]

I might add I use a lot of power poles here,, If you wish to go that route get yourelf a handfull of power polse and if you are parked near me I have the tool to crimp the contacts onto the wires for you.

I got mine from West Mountain Radio.. It bears their name, but is identical (otherwise) to units sold by other companies.. The first time I used it I noticed the crimp job it does is as good as or in some cases BETTER than some factory crimps.

[landyacht318]

I have a certain amount of delegated tinker time for improvements to my interior ergonomics. There have been occasions where I needed the laptop converter, in someone else's vehicle. For that reason I stuck with the standard ciggy plug.

I do have some Anderson powerpoles ordered.

http://www.amazon.com/Anderson-Powerpole-Connectors-Pair-Genuine/dp/B00AM4VF9O/ref=sr_1_fkmr0_1?ie=UTF8&qid=1385376325&sr=8-1-fkmr0&keywords=anderson+powerpole+75+amp

10 for 10 bucks rated at 30 amps. Mostly they are going to replace the SAE 12v connectors I found to also be inadequate for bigger loads, even with 10 awg leads.

[westend]

That is way more time than I would have spent on those connectors and I usually waste inordinate time on making something work that is doomed to fail. :B

IMO, using any connector that relies on a spring or spring steel contacts to make connection is a losing effort unless it is never disconnected. The springs or metal bars lose tension after a while and connections become tenuous. Your story kind of reinforces this.

The Anderson Powerpole is a great connector but spendy, relatively. For anything under 20 amps, the Neutrik connectors are my go-to connection. They are inexpensive and reliable, easy to connect to small gauges of wire, and are sold throughout the world.

Good to hear you're charging, though. Attaboy!

[landyacht318]

landyacht318 wrote:
as no doubt at some point this issue will return.

Well it returned.

The spring turned to mush. Turned from chrome colored steel to a fully compressed springless piece of coiled steel, which looked galvanized.

The 10 amp glass fuse has a couple drips of solder pushed out from between endcap and glass. It had no continuity. But the part designed to fail, looked perfect.

there was no damage to the plastic housing. I replaced the spring, I replaced the fuse. I use a small narrow diamond dremel bit to cut some teeth onto the ground springs so they grab the receptacle tightly.

But I also ordered a Blueseas locking plug and receptacle. It arrived today.

Kind of impressed with the design.

For your viewing pleasure:


The ground spring is one piece.
It has a rubber seal right at the edge of where the two meet.
The set screws are designed to crush the wire.


The receptacle has detents to help lock the plug in place. It can still be removed from the plug when in these detents, but it requires more force than elsewhere in the plug, and more force than any other plug I've ever used. Not sure I am buying the twist to unlock claim. That requires even more effort to remove the plug than pulling it straight out


The rubber seal is also very tight. I'd believe the splash proof claims. With this plug inserted fully, water is not going to get inside. Not really a factor in RV usage, but between the rubber seal and the locking feature, there is no way the nipple spring is going to push the plug out of the receptacle, even in a high vibration environment

[lane_hog]

For my laptop, I bought a smart "air-auto" brick from HP which managed the DC to DC as well as AC to DC. Quite similar to the iGo Juice adapters from a few years back, I've found that the adapters which say they're also good for airplane use usually have a more substantially built cig plug to accommodate a now-extinct plug used on airplanes about ten years ago. Those are getting harder to find as airlines install universal outlets onboard.

Last weekend, I ran a 110v line from our mid-coach inverter up to the cab. The only thing we now use 12v plugs for is our GPS... The solar panel allows us to be a bit greedier on our power use than we were with just batteries.

[landyacht318]

My dc to dc power brick is rated for 90 watts, just like the provided ac/dc power brick, and the current is being measured by my shunt for my battery monitor.

I could not get this new ciggy plug hot charging the depleted battery while watching a DVD which is likely close to the 90 watt limit.

I am going to conclude that the ground springs had weakened from always being compressed in the socket, and that the nipple spring was then making poor contact heating up and compromising its elasticity and ability to pass current and the problem compounded until I smelled melting plastic, and/or I saw my screen dim and the charging icon goto the battery icon.

The second ciggy plug I soldered on was poor quality and design and just not up to the task and I should not have used it and let it convince me there was a larger problem elsewhere.

The third ciggy plug that came with my new inverter is now just getting warm passing everything the laptop can demand through the DC to DC brick.

I have a mattress heating pad that came with a ciggy plug. It draws 6.2 amps max. While that plug gets warm too, it seems like a much heftier design which I might research and obtain as no doubt at some point this issue will return.

[BurbMan]

Most of the laptop bricks I have seen in recent years output 16v-19v DC to the laptop to charge the battery. If you have a special DC-to-DC brick that inverts 12v at the socket to 19v at the laptop, then depending on where you are measuring amp draw, you could be drawing more than you think at the actual socket connection. As was said I think those ciggy sockets are rated for 10a max.