Ciggy plugs, the male ends, are horrid connectors, and they only get worse with age.
The problem is the ground springs on the side are steel( not a great conductor), and the nipple contact can also be steel
When the steel
gets hot, as it will passing 7 amps at 12 volts, it loses its spring, and then the nipple spring can push the plug
out of the receptacle. Then less surface area is passing even more current
, due to the voltage drop, and this just gets worse and worse, until the spring on the internal fuse gets so hot, it melts into the plastic housing.
Check out this discolored compacted spring
I've been using DC to DC car adapters on my laptops for 10 years. My ciggy plug
receptacles are wired with short lengths of 10 awg. The male ends of the car adapters are the issue. I've never gotten more than a few months before I replaced them.
It did not matter how pristine the contacts were, how tightly the springs grasped the sides of the receptacle or how tightly the nipple spring was pushed against the end of the receptacle. Failure was always just a matter of time.
And it always happened with a depleted laptop
battery when streaming a Movie
or watching a DVD
and the laptop
was drawing 90+ watts.
Last time it happened, I wired up some 30 amp Anderson Powerpoles. Problems ceased entirely.
Now I have 7 ciggy plug receptacles, and I will only use them on devices that draw 50 watts or less.
Ciggy receptacles might be ubiquitous, but they are a horrible, unreliable connector. It is just a matter of time before they fail. The quality of the receptacle means little when the male plug is China's cheapest.
And, Before they fail, they are wasting battery power as heat.
I used to have a 12v mattress heating
pad, and it had a quality, but fuseless Ciggy plug, and it would pass 6.2 amps maximum. When I cut off this ciggy plug and installed Anderson powerpoles, the pad was able to draw 7.4 amps, and it heated up significantly faster, and overall used less battery power and was significantly more effective when temperatures got cold enough to turn it all the way up all night long
Cut the Ciggy plug off, and stop wasting battery power as heat on horrid connections.
BTW the anderson Powerpoles, 15 amp/30 amp, and 45 amp are all the same size and mate with each other. The actual contacts inside are slightly different where the wire is crimped into them. 15 and 30 amp versions require a normal crimping tool. The 45 amp ones require more crimping skill or the use of their speciality tool.
I've taken to crimping and soldering the 45 amps ones, no longer bothering with the 30 amp versions.
I use these inexpensive watt meters inline anywhere where i have employed Anderson powerpoles:
130 Amps Power Analyzer with High Precision G.T. Power RC Watt Meter - - Amazon.com
I remove the 12awg aluminum
leads and solder 8awg tinned marine
wire to the circuit board shunt, and pass 40 amps through it and it barely gets warm.
Here is one on my fridge:
Here is one on my Meanwell rsp-500-15 adjustable voltage power supply:
Right now I have one on my Dell latitude e5500. the laptop battery is full, the meter indicates 54 to 67 watts, and it has consumed 12.34 AH since I plugged it in some time this morning.
It is accurate down to about 0.8 amps according to my larger shunted battery monitor
, and my DC clamp meter. At 40 amps, it reads about 1 amp high.
So hardly a perfectly accurate tool, but much better than guessing.
The wattmeter also reads Watt hours, Watt peak, amp peak, and minimum voltage. I'd not trust it to pass much more than 20 amps continuous with the 12awg leads provided. I only trust mine at 40 amps because of the 8awg I installed.