Recent content by sremick

Something else worth noting (that Dacian mentioned to me) is that, although the serial port is technically 2 wires, because the SBMS can't/doesn't receive any data you can get away with one wire. There was also the necessity to opto-isolate or magneto-isolate the serial line between the two...

A portable battery power kit (charge controller, batteries, inverter, connectors, etc all in a compact box). It began with wanting an external display showing specific data I cared about but then morphed into all sorts of other enhancements as I came up with ways I could control/respond to...

I have done this for a project I was working on, although I haven't touched the project since 2021. I was surprised at the time that no one else had done this before as I too was frustrated by the complexity and was hoping like you to build off from someone else's code. But even emailing Dacian...

They have 3 serial interfaces. You can check all the specs at: https://www.pjrc.com/

Check out the Teensy microcontrollers. Ardunio-compatible but with more storage and data pins. The Teensy LC has 27 data pins and 64KB storage. The 3.2 has 34 pins and 256KB. I've been using them and been happy.

Logic level converters. I've used them, they work great.

Pretty easy to make. I made my own. You can buy the braid on eBay. I got nickel-plated braid and plated copper tubing since the battery terminals are aluminum (grr) and copper+aluminum=bad

One nice thing about flattened copper tubing is that you can flatten it over lengths of copper braid, since there are risks with using solid bus bars damaging the terminals as batteries expand/shrink.

Phantom power drain even with no load on the inverter.

It's for small units (portable) where size/space is a constraint. Not every use case has the luxury of unlimited space/weight for more batteries and more panels. When some variables are limited, it's reasonable to want to save the 10-20% lost efficiency of an inverter if a straight-DC solution...

The video Bud posted 2 pages back from Bigbattery.com re: their Lishen batteries suggests otherwise (they're wrapping them specifically to insulate them electrically)

I'm going to test my EVE cells next time I pull them out from my work-in-progress project. I'm rather shocked that the outer case is tied to one of the terminals, considering how frighteningly thin the blue wrap is. I know for a fact that simple handling of them nicked the blue wrap in a few...

My current plans for my portable kit includes something along these lines. Although it won't be particularly well-calibrated... mostly to satisfy my curiosity in how cell pressure changes relatively over the course of the charge cycle. I'm still working out the details and it depends on whether...

Cost and weight. Aluminum is 1/3rd to 1/4th the cost of copper, and 30% of the weight. But mostly cost. Those Yuans add up.

2ch isn't totally necessary, since the solar panels aren't permanently connected. They're only plugged in while it's being used, then unplugged when it goes into storage. Knowing to always make sure the panels are unplugged before throwing the battery disconnect to OFF would not be a problem...