Grid tied battery backup for CPAP design help

[Quest50]

Now that is project creep. We started out trying to fit it in a satchel smaller than the CPAP machine.

Huh? The battery itself is significantly larger than the machine. It looks like the overall dimensions are going to end up being 13"(w)x18"(h)x7"(d).

Scope creep has been all the attachment points..... I've got USB-A, USB-C, two vehicle auxiliary (cigarette lighter) outlets, and I've had to restrain myself from adding anderson connectors.... Like maybe an SB50 for the charger, and a SB175 on the side for if I wanted to be able to expand capacity by really easily putting another battery in parallel.....

This is a satchel built to government specifications.... or was that what an elephant is? a mouse built to government specifications

Yeah, the size was never a requirement, but all this other stuff definitely reeks of scope creep. I'm having a lot of fun with it though and I'm learning a LOT. I'll also use about any excuse to pick up a new tool... So I've picked up a few tools for rivets... I had no idea Rivnuts were a thing. SO COOL!

 

[robbob2112]

HA HA, rivnuts have been the bane of my existence time or two.

 

[Quest50]

HA HA, rivnuts have been the bane of my existence time or two.

Yeah, some of these do seem to be a little finnicky with the grip range. I've been playing with a few of them on some test pieces of .065 wall tubing and some .125" sheet. What difficulties have you encountered?

 

[robbob2112]

Of course when I used them the few times I have, I used a bolt, multiple nuts and washers as a home-made install tool. There are youtube instructions on making it. That might have been my problem.