12V computer power

[gnarledwolf]

Hey guys,
     As always I'm trying to push my resoureces.  Can anyone tell me how well these: PWR+ 90W Laptop Car chargers work?   It makes more sense to me to not have to run my laptop through a converter then back to dc to run a laptop when I can just run strait dc/dc. I'm told I can consume half the power using that setup.  Can anyone confirm or deny this?

 

[jimindenver]

No experience with the device but it's not a bad price.

You do save some by not using a inverter but not half.

 

[29chico]

You probably will save about one third of the energy that you would consume if you used an inverter to power your laptop's AC driven power supply by using something like the Pwr+.  Cutting your draw in half is not realistic in my opinion.  The device that you are asking about still has to boost the power up to the laptop's DC voltage requirements, that is usually in the 18-20v range.  So an energy loss to boost up the voltage still happens.

I am a Lenovo guy, have a few of their laptops, and recently bought the below linked multi-input Lenovo travel power kit.  It can be powered by house, car or airliner current input. Not as cheap as the Pwr+, but probably has a cleaner DC output and may also be less likely to go up in flames...

http://www.ebay.com/itm/222014448743

 

[SternWake]

50% is possible, depending on the device and the inverter used.


Say a device only draws an Amp turned on Idling while reading something online.  Say the inverter has a 0.8 amp unloaded draw, and add in 20% more inefficiency for the DC to AC conversion, then AC back to DC.  50% is unlikely, but possible when the device is using little power and its battery is fully charged.

I have been using a 90 watt PWR+ for many years now.  the only issue is the Ciggy plug wears out  and partially melts passing 70+ watts.  After the second replacement of ciggy plug began to fail, I went to Anderson powerpoles.

Mine also had an issue with the output wire simply due to the treatment I give it.  My Dell has a third pin, The wire to this pin failed and it would power laptop but not charge the battery. bought a 5$ 120vac  dell adapter, and cut the output wire off of it when it arrived and spliced it onto the PWR+.

I did some tests on the amp draw of the PWR+ vs the 120Vac transformers/wall wart/ powerbrick on an inverter.  Don;t remember the numbers offhand, but the savings was significant.  not 50%, but more than 15% that's for sure.

 

[TMG51]

While we're on the subject of the nuances of computer power... Which is more energy efficient, leaving the computer plugged in all the time during use, or charging up its battery and unplugging it until it needs recharging? For the example let's assume DC and no inverter.

I used to alternate unplugging my laptop while working during the day and let the battery cycle down. But, after experimenting a bit, I think that the charger is only topping off what the laptop battery needs when it's plugged in, rather than putting out a constant xx number of watts the entire time.

If output were a set constant then it would be more efficient to alternate unplugging the laptop. But I think it takes what it needs. Now I just leave it plugged in the whole time during use.

 

[jimindenver]

If I were to only use the computer or any rechargeable device while plugged in, I would take the battery out if possible. I haven't had the battery in my netbook for over a year.

By sheer dumb luck I made it easy on us by getting the 2 in one windows tablets. They can run/charge off of the brick or the mini usb. A simple 2a USB cigarette charger or our 10000 Ma external batteries run them, the phones, hotspots and bluetooth devices. Not much need in the trailer but it sure is convenient on the road every by not needing multiple adapters.

 

[WheelEstate USA]

Matt...I think the use of a PWR+ is worth it in the long run. 
As with many things that use ciggy plugs, they will benefit by using the above mentioned Andersen Power Poles that can also be ordered from The River (Amazon).

 

[SternWake]

Which is more energy efficient, leaving the computer plugged in all the time during use, or charging up its battery and unplugging it until it needs recharging? 

PLugged in all the time means less accumulated cycles on the laptop battery, and less load on the lead acid battery.  

 A charging laptop, still in use, can exceed 7 amps.  If only one 100Ah battery is used, this is over the 5 amp load at which the battery earned its 100Ah rating.  A 7 amp load would then make that 100Ah battery have less total available capacity, but if the laptop were kept charged the steady load might only be 2 to 2.5 amps, well under that 5 amp load that the 100Ah battery could power for 20 hours before voltage fell to 10.5v/100% discharged.

Save the laptop battery for the morning hours, when the solar is needing to get  the battery upto and then held at absorption voltage in the mid 14v range, ASAP.  Once it reaches ABSV, then amps will begin to taper and at some point  soon after enough solar excess is available to both hold battery at ABSV, AND to charge laptop battery. 

If one is going for an hour drive in 2 hours, then cycle the laptop battery and charge it while driving as the alternator can likely make up for the excess, but the solar, likely not.

 

[K1ngN0thing]

I bough the PWR+ for my Thinkpad. Only used it once when the house power was out, but it worked fine. I think I paid around $20. Definitely worth it, especially for the ability to charge while you drive, and because my inverter is a 1000w.

 

[akrvbob]

I've got one for my lenova and it's been great. No regrets on buying it.
Bob

 

[gnarledwolf]

Matt...I think the use of a PWR+ is worth it in the long run. 
As with many things that use ciggy plugs, they will benefit by using the above mentioned Andersen Power Poles that can also be ordered from The River (Amazon).

That's the way i was seeing it too, jay.  Anything that extends my power reserves is a great idea.

 

[gnarledwolf]

Made no noticeable difference as far as I could tell... and I had to make different wire arrangements for other electronics that made it unfeasable... at least now I know.

 

[SternWake]

As far as the PWR+ brand goes, yet the ciggy plugs themselves will eventually fail if passing more than 60 watts often, and most ciggy plugs are of poor design and will also fail when regularly passing 60+ watts.

When I have grid power available, I do not switch to my 120vac laptop provided power supply, but keep using the PWR+ dc to DC laptop car adapter and use my battery charger/converter/adjustable voltage power supply to keep my Lead acid batteries at 13.6v, or 14.5, or whatever I want.

I had done tests in the past regarding the original power brick on my MSW inverter, PSW inverter and PWR+ DC to DC adapter, and the PWR+ wins easily on the amp draw ranging from 12 to 50% more efficient than the inverter powering the original power brick.

If one is powering an inverter to ONLY power the laptop, they are wasting power to do so, the PWR+ or similar laptop car adapter is simply more efficient, and a wise investment, even if the ciggy plug provided with it is doomed to failure, at some point.

My original, Dell provided 120vac adapter has failed.  Its replacement is a PWR+, but it only gets used when I take a plane ride somewhere.  So it does not seem much use.

If one is trying to minimize battery consumption, the first most effective easiest step is replacing interior incandescent lighting with LED, second is the Laptop car adapter.

 

[StarEcho]

As far as the PWR+ brand goes, yet the ciggy plugs themselves will eventually fail if passing more than 60 watts often, and most ciggy plugs are of poor design and will also fail when regularly passing 60+ watts.

I have an older laptop that does take the more than 60 watts.  I have the OEM 12 volt power plug for it.  I'm just wondering if I can cut the ciggy plug end off and switch it to anderson connectors?  

A weird thing I've noticed is that when using the 12 volt power plug for the laptop, the reception to the TV is fuzzed up.  When I use the 110V power plug with my inverter there is no TV interference.  Would that indicate I've got a bad 12v power plug?

 

[LeeRevell]

I would suspect the 12V unit lacks the proper signal filter, and the AC Inverter has it built in.  You could try separating the 12V power unit from the TV as far as possible, that might minimize the interference.  Or get a signal or powerline filter.  Cheap insurance at most electronic suppliers.

 

[SternWake]

 I'm just wondering if I can cut the ciggy plug end off and switch it to anderson connectors?  

A weird thing I've noticed is that when using the 12 volt power plug for the laptop, the reception to the TV is fuzzed up.  When I use the 110V power plug with my inverter there is no TV interference.  Would that indicate I've got a bad 12v power plug?

The Ciggy plug has a fuse inside it, to protect  the wiring from ciggy plug to the plug at the power brick.  If one cuts off the ciggy plug, then one loses this fuse too, so the wires feeding the Anderson powerpole, should goto the fuse block, and be fused at the same rating as the fuse which came  inside the Ciggy plug.

Or, one could put a ATC fuse or similar inline near the anderson powerpole itself, but consider a fuse necessary somewhere on the circuit, rated at the size fuze that came inside the ciggy plug.

The electrical interference with some power supplies is common.  Channel 8 in my location is basically my strongest station, but also most effected by my PWR+ Adapter, but only when it is working hard to recharge the laptop battery.  If the laptop battery is full then much less interference occurs.


My PSW INverter turned on powering nothing, can also do the same thing.  I have tried to watch channel 8 while charging laptop battery with the original power supply, and the PWR+ 120vac replacement and both would do the same thing to channel 8.

Snap on Ferrites on the power cords to both TV and PWR+ can help reduce interference:

http://www.amazon.com/Ferrite-Core-...1-6297549?ie=UTF8&refRID=1R8APQNSZKXQEWCJEYRT

One can often salvage these from older device's power cords!

It also helps to separate the12v power cords that run parallel to each other, but this is not always convenient or possible.

Twisting the power leads tightly in a drill, in my experience, is the most effective way of reducing interference of LED bulbs and power transformers affecting my TV stations.  Combine the twisting of the leads with some snap on ferrites might easily make TV stations reappear, that were once chased away by an LED light or another electrically noisy device. Twist he TV's power leads too. I know it is not really possible to twist the leads in the PWR+ cord as they are round and sheathed.

I might try running new twisted leads from powerpole to the circuit board of the PWR+. but honestly my project list had other things more important on it.

One can also try turning off the Laptops ability to recharge its internal battery. this might reduce the interference enough to keep watchin the affected TV station and keep the laptop on.

Shielding the PWR+ body, line of sight wise, with some aluminum foil folded a few times, 'might' also reduce the interference enough to keep watching the affected TV station