Inverter and laptop

[Manitou]

I've got a cheap (but well reviewed) bestek 300w inverter. It worked to charge my laptop at first, but seems to struggle when the laptop battery is low (60% or less). When it was at 5% it wouldn't even cycle off and on like it did when it was at 60%. It's a newer MacBook Pro but don't think it's draws more than 300w. It could be that the I lower the battery charge, the more it draws and perhaps really is too much for the inverter. Or could it be this "modified" vs "pure" sine wave stuff?

[Blue~Go]

I can't speak to the inverter (so why am I even replying ), but I can say that I charge my laptop all the time with a 12-volt adapter (in other words, a special cord that plugs directly into a cigarette outlet) and have been doing so since 2001 with no problems. I have used both a Targus brand (came with various interchangeable tips for assorted laptops), and now a We Charger brand one (single tip). These were all Macs, but a friend also used the Targus for years on his Windows laptop (with one of the other tips).

I will say that at one point said friend got an UltraSuperPowerfulHuge Windows laptop, and with that one no 12-volt adapter would work, so he had to go the inverter route (less efficient) (it was a stand-alone inverter, not hard wired).

At any rate, if it is possible for you to get a native 12-volt adapter (computer does not have to be 12-volts, mine is 19v, IIRC), it uses quite a bit less power. I did some testing at a friend's RV who has a hard-wired inverter. My laptop, being used and plugged in and charging directly via the DC cigarette outlet charger used around 3 amps. Same situation but plugged into 110 (through inverter) used over 5 amps. The extra amps were a combination of less efficient charging, plus "base penalty" for having inverter on. Still, even with the inverter on anyway so not counting base inverter usage (say using it for other things), the charging still took more amps via 110/Inverter than via cigarette lighter plug-in.

[Manitou]

Is this the sort of thing I have to order online or ?? Walmart? Frys? (Bestbuy mark up pisses me off)

[Blue~Go]

I think I got my old Targus ones in a store (Circuit City)? But that was over ten years ago. I got the We Charger ones within the past year, from Amazon. If you don't have a Mac it's fairly simple (with my era of Mac it's a bit harder as they have a proprietary magnetic plug, but even then it's not impossible). I think other companies such as Kingston, etc. also make them.

[Concourse]

It could be that the I lower the battery charge, the more it draws and perhaps really is too much for the inverter.

^^^ This

[Manitou]

Yea, I confirmed today that at 80% charge, the inverter will handle it fine. Still going to look into a direct DC charge solution when I get to a real city in a few days.

[1998chinook]

A few weeks ago I purchased this inverter from Radio Shack to run my macbook pro and have not had any issues.

[Manitou]

Odd.. Mine is a 300w but it is the newer MacBook. Retina display SSD hard drive and 16 gigs of ram (I work through my laptop).

[Blue~Go]

Since you have a Macbook, here is the charger I have been using lately. My Mac has the Magsafe 1, but they also make a version with Magsafe 2. I ordered the Magsafe 2 version for a friend with a ~2014 13" Macbook Pro Retina, and he used it all winter (out Class B RV-ing) and no complaints.

I do have one minor complaint about these chargers: The part you plug in is a nice sleek design, but since it is tapered it can "creep back out" of some cigarette sockets that are not snug.

Also, the cord is not super long; on the other hand there is no "brick" so they are compact. I've been using one daily for over a year and recently bought a second one just so I can keep on in the rig and one in my backpack.

http://www.amazon.com/WeCharger-Ultra-C ... harger+mac

Not to say you have to use Amazon, but the link shows the ones my buddy and I bought and use.