This morning, I ran my battery bank through the paces to eliminate problems one by one. The problem is either my inverters or my laptop. I can’t imagine having three bad inverters, so the answer must be the laptop.

I’m running off a battery that’s at about 97% right now (12.5V) with a draw of about 0.3 amps, which is the fridge. BTW, I never, ever run my fridge on auto, so it cannot switch over to electric.

If I turn on the big inverter. No problem, I’m now drawing about 1 amp. Turn on the UPS for the office stuff and run the external drives. No problem, I’m below 2 amps. Plug in the laptop and it charges for about five seconds, long enough to tell me I’m drawing about 6 amps, and then the inverter starts shrieking that the voltage is too low.

I pulled the Kill-O-Watt metre into the inverter to see what kind of wattage the charger is drawing right before the inverter cuts out, and it fluctuated between 90 and 120 watts, the lower end of which is comparable to what the battery monitor was telling me.

So I finally did a search on solar powering a MacBook Pro and, surprise, surprise, there is no easy answer… because the MBP requires a higher voltage than that supplied by an RV system. There’s the answer! The MBP is trying to draw something like 16V out of my system, which obviously won’t work!

I found many references to a guy who has successfully hacked a Magsafe MacBook brick to run straight off of 12V power, not through an inverter. It’s pricy, $170, but if that’s what it takes, that’s what it takes. In the meantime, I need to find a Starbucks. Gaaaaaaah. Apple, why do you do this to me!