Laptop charging

[hoppy]

I have a MacBookPro and bought an aftermarket car charger for it. Every now and then it heats up the cig lighter plug and it actually melts. So now my 3rd plug has died.

I also have a basic pure sine wave inverter (no idea of the watts) that I can also use but it seems to draw way more amps than the car charger and for some reason it really does not like being used when the engine is not running. It starts squealing and I assume it's because of the voltage drop. It also runs from the cig lighter outlets.

I am guessing that the cig lighter plugs I've been using just can't handle the amps. In one of them, the positive connected to the fuse via a tiny spring and I assume that is what was causing the heat. It was probably glowing red.

I'm pretty much resigned to no longer trying to use the cig plug for the car charger. I'm thinking I should find another type of plug/outlet that is rated for at least 10A and use that instead. I'd possibly bypass the 12v switch and connect it directly to the 12v supply with the appropriate wire and fuse.

Any thoughts?

What do others use?, do you use an inverter or a "car" charger for your laptop?

I suspect I need to invest in a decent inverter.

[Pete7]

Hoppy, it could be that the female part of the ciggy plug is at fault. Swop them both out for a decent quality plugs.

I run out old Dell laptop via a 12>19 volt charger and its fine. I also have a sterling 150w coke can charger which runs everything else including the 100w soldering iron, 240v electric sander, dewalt drill charger etc.

Also worth checking the wiring from the battery switches to the back of the socket, are they up to it or just thin bell wire?

Pete

[hoppy]

Originally Posted by Pete7

Hoppy, it could be that the female part of the ciggy plug is at fault. Swop them both out for a decent quality plugs.

I run out old Dell laptop via a 12>19 volt charger and its fine. I also have a sterling 150w coke can charger which runs everything else including the 100w soldering iron, 240v electric sander, dewalt drill charger etc.

Also worth checking the wiring from the battery switches to the back of the socket, are they up to it or just thin bell wire?

Pete

Ok, I'll take a look at the female and the wiring. One of them I put in, but both cause me grief. I'll will be in civilisation for a few days next week, so I think I'll go to a specialist electronics store I know and see what quality plugs they have.

[roverhi]

Suspected it's your power receptical. Did you buy a marine specific model or just an automotive one. Got a boat double hole model from West marine that's worked fine going on ten years. Came with caps to protect the innards when not in use. Charge things using a small cheap inverter plugged into it. Probably not very efficient but solar panels give me energy to burn.

[Jon Eisberg]

Originally Posted by hoppy

I have a MacBookPro and bought an aftermarket car charger for it. Every now and then it heats up the cig lighter plug and it actually melts. So now my 3rd plug has died.

Yikes, THAT is scary...

Originally Posted by hoppy

I am guessing that the cig lighter plugs I've been using just can't handle the amps. In one of them, the positive connected to the fuse via a tiny spring and I assume that is what was causing the heat. It was probably glowing red.

Are you sure everything is OK with your charger? I'm using a 12-19V charger from MikeGyver for my Mac Book, and the plug never becomes dangerously hot, that I've noticed...

For a more robust connection, you might consider a Trolling Motor plug/connection... I use one to hook up my wind and hydro generator, it makes a very secure connection, and handles the loads with ease...

MARINCO ConnectPro Trolling Motor Plug & Receptacle | West Marine

[hoppy]

Originally Posted by Jon Eisberg

Yikes, THAT is scary...

Are you sure everything is OK with your charger? I'm using a 12-19V charger from MikeGyver for my Mac Book, and the plug never becomes dangerously hot, that I've noticed...

I really don't know. I might look for another one as my charger has the old style power connector for mac and I'm sure I'll lose the adaptor one day.

With the charger I've had problems with it getting hot if I let it lay on it's side.

[GrahamHO]

I tried a square wave inverter and it caused harm to my MacBook battery which later self corrected when charged on mains. Then I bought a pure sine wave inverter of more than adequate wattage. It had a cigarette lighter plug and wouldn't charge the MacBook just as you describe. I took it back and after several tests the supplier part exchanged it for a higher wattage pure sine wave inverter. This one had terminals for hard wiring the 12 v supply. I took fairly heavy cables in keeping with the terminal size back to the switchboard including an in line spade fuse. That works perfectly. This inverter is much larger capacity than the MacBook theoretically requires and was the smallest pure sine wave that could have the 12v input hard wired.

The problem seemed to be not the rated wattage output of the inverter but the restriction caused by the cig lighter plug and its attached lead. Now with a domestic multi output box plunged in it has no problem charging MacBook, iPads, and phones at once.

By the way I use an Elgato TV tuner on the MacBook and with a marine Omni directional UHF antenna on a short mast above the transom I get hi def UHF TV when anchored in the right places.

[skipmac]

First thing I would check would be the wiring to the plug. Lots of cigarette lighter plugs are wired with small wires and designed only for a small load.

If the battery in the laptop is way down the car charger can pull a lot of power and exceed the capacity of the plug and wires. You will need a good quality plug with good sized wire running to a large breaker or fuse on your DC panel.

[hoppy]

I guess to be sure, I need wire for 10A. I just found an online calculator that says I need 4mm cable for a run of only 1m

Looking at it again it's for calculating for solar with an acceptable loss. Probably a good size anyway


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[laika]

Someone mentioned mikegyver. They have a lot of good info on 12V mac charging and offers some nice albeit expensive gear. They sell a very nice $500 52AH lithium battery (that also comes with a standalone 12V charger and "L" shaped mac connection). Also some less expensive options.

Make sure the output voltage of the charger youre using is what the mac wants. My macbook pro 2012 wants 16V.

I have the 52AH battery and it has been very handy. Solar charges battery during day and all computers/phones plug into overnight so the house bank is never drawn down. Obviously, a larger bank would make this less of a concern.

[UNCIVILIZED]

Were it me, I'd also check (measure) the true power draw of the computer/charger, with a meter. That way you can know for certain if any of the OEM wires anywhere in the charging system or components are undersized. And you can appropriately size them yourself... Using the suggested sized wires for a 3% drop (or less).

Also, make sure that none of the wires in the charging system are tightly bundled with other wires, as such prevents them from properly dissappating heat when they're in use.

BTW, using the correct type of terminal connections in higher draw type loads is huge. If you use the incorrect ones, or they're improperly fastened (to the wires themselves, or @ their end points), it can cause a LOT of heat in the system/components. In addition to causing poor charging... which causes the charger to try & draw more juice through the already overheated wires/parts... Your classic escalation type spiral.
Basically, as Tarzan would say, "That's bad Juju, Bwana".

[Rusty123]

Im not a Mac user, so Im speculating here, but perhaps you could use a regulated dc-dc converter in the appropriate voltage/wattage with a proper pigtail, instead of the all-in-one cigarette plug/converter. That way you could connect directly to your DC distibution panel (with appropriate OPD).

(This approach assumes that the charging logic resides in the laptop, and not in the charger. Dont know how macs are configured).

[leftbrainstuff]

Your car cigarette lighter might not be rated for the current drawn by your macbook.

A good 300W inverter should work.

You might also like to see why your macbook is drawing so much current.

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[SVRapture40]

I had a similar problem - turned out it was the USB adapter that I was plugging into the cigarette plug. My wife brought a fire extinguisher out because she thought it was going to catch fire because it was so hot.

I did some research and bought a Scosche 12w x 12w adapter. It is designed specifically for Apple products, but does seem to work fine for my android phone as well. It was $14 from B&H Photo online. Of course it is 5 volts so make sure that is what your Mac needs. Result - I can charge my iPad and phone at the highest rate they will each take and the whole apparatus stays cool as a cucumber.

[GrahamHO]

The hard wired sine wave inverter that I mentioned before, that works fine charging a MacBook is over 300 w maybe 350 w but it's not in front of me.

The one with the cigarette lighter plug that wouldn't work with the MacBook was around 270 w from memory. I had wired the lighter type socket in the boat myself with the heaviest cable that I could attach to the socket with a 2 wire run of less than 1 metre. Neither would that inverter work with a MacBook when tried in a couple of cars.

I don't think lighter type plugs are very satisfactory because of the restricted size of cable that is possible fit into the confined space inside the plugs. I'm well aware of this because just yesterday I wired a couple of them for another project. That and the connection inside the socket where the spring loaded plug positive pin is trying to push it out of the socket.

The inverters with lighter plugs are only made that way to make it convenient for car owners.