I have a ton of Ryobi 18V batteries that could be used to supply power during an outage or a camping trip.

Here's my latest design of a Ryobi 18V Power Adapter. It provides regulated 13.8 VDC/10A to a cigarette lighter socket. There are a variety of USB cigarette lighter adapters that you can plug in to charge phones and power laptops. It can run a CPAP or a 12V freezer.

I've developed more high-end ones in the past ( https://www.thingiverse.com/thing:4168822 ). I found a small simple design on thingiverse (https://www.thingiverse.com/thing:4105591 ) and remixed it by adding a cover ( https://www.thingiverse.com/thing:4561390 ).

Here is a youtube video that describes the project: https://youtu.be/C2XiyP9vXhw

Here are the parts I used:

• RYOBI 9Ah 18V battery ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• BESTEK 300Watt Pure Sine Wave Power Inverter Car Adapter DC 12V to AC 110V with 4.2A Dual Smart USB Ports ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• USB type c charger ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• USB QC 3.0 charger ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• Spring Clips ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• DC Voltage Reducer Automatic Buck Boost Converter DC 8V-40V to 13.8V 10A Step Down Up Regulator ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• 12V Marine Sockets ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• Original Prusa i3 MK3S 3D printer ( https://www.prusaprinters.org/ )
• USB Load tester ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• ICECO 12VDC compressor freezer ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• RYOBI RYi150BG 150-Watt Powered Inverter Generator, with 2 USB Ports and One 120-Volt Outlet ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )
• RYOBI P743 ONE+ 18V Portable Power Source 2.1A USB ADAPTER ( https://www.amazon.com/Ryobi-18-Volt-Lithium-Capacity-Battery/dp/B07HS1BK57/ref=as_li_ss_tl?dchild=1&keywords=ryobi+9ah+battery&qid=1597204265&sr=8-3&linkCode=sl1&tag=simple3d0e-20&linkId=d33869be32738458b34e4227176af8b3&language=en_US )

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