I take my MacBook with me while on vacation in my travel trailer. I have a 100 Watt solar panel and would like to charge my computer using the DC power supplied by the panel. What is the recommended method?
Yvonne’s MacBook Pro
The charger supplied by Apple requires an AC electrical source. If you must use your solar panel, I suggest you get and inverter to covert DC to AC so you can plug in the charger to it. But be aware, just because the panel is rated at 100W does not mean it will always supply that. Intermittent clouds and dreary overcast days you know.
Your MacBook Pro uses ‘smart charging’ to charge in the optimum way, and only when necessary. Plugged in is Not necessarily actively charging. There is substantial hardware and software cooperating on battery and charging issues. Simply asserting a charging voltage against one of the interface(s) will NOT successfully charge your MacBook Pro.
Any external power supply that provides "USB Power Delivery" (including certain displays) must negotiate over the USB cable using USB Power Delivery Protocol, and can not 'force itself' on your Mac. The Voltage and Current are delivered only after your Mac requests and the charger agrees to supply power under certain controlled conditions. The computer is in control of the entire process.
if no other device with USB-C power delivery protocol is available, your recourse is to use AC as the interchange, and plug in the Apple Power Adapter.
To charge your MacBook Pro using the DC power from your 100 Watt solar panel in your travel trailer, you can use a solar inverter. A solar inverter converts the DC power from the solar panel into AC power, which your MacBook Pro can use for charging. Make sure to get a solar inverter that matches the specifications of your solar panel and MacBook Pro for safe and efficient charging.
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That can get you the power levels you need, on the order of 100 Watts at around 20 volts.
But you still need a device that support USB-C Power Delivery to negotiate with your Mac to accept any more than a trickle charge.
Thank you for your answer. My MacBook seems to charge okay using an apple charging cable using a cigarette lighter usb but it sometimes charges very slowly and sometimes very well. I was looking to find out what the best and safest method was for my computer. It also works in the car but slowly. Will use shore power whenever possible but it’s not usually available where we camp.
Regular 5V USB power like from most car chargers can help 'top off' battery power, but substantially charging that way could takes days to a week when the MacBook Pro is NOT being used.
Charging MacBook Pro from solar panel
