I haven't given up or anything. I did, however, get sick as hell, and then distracted with more urgent projects.
One thing I did was test/implement my "affordable alternative" for battery protection. Here they are, hooked up to my electric bike's battery:
Tapped in at the BMS connection:
(you can see my EV cells hooked up in parallel behind them, getting properly balanced)
They're dirt-cheap battery monitors off of Ebay for about $1.50 ea. They're meant for monitoring RC Lipo batteries. Each one monitors up to 8 cells. They have a low-voltage alarm on them, which you can adjust the voltage for, starting at 2.7v and up. The alarm is decently loud, without being loud enough to drive you up the wall in a hurry.
For now, I'll couple these with a cheap BMS, which is essentially there to prevent over-charging and give a bit of balancing. They're too small to control the large currents, so some form of external cell/voltage monitoring was needed.
Crude? Perhaps. But I'm not forking another grand or more for a full blown BMS. Yet I still need to protect my batteries, or I'll end up killing off a cell at a time. This should do the trick.
I've had them hooked up to my little battery pack for over a week without charging, and the pack voltage has barely dropped a couple of tenths, in spite of the cells being in the sharp part of their charge curve, where they drop off quickly to nominal during discharge. Meaning these little guys are barely taking more power then required to light the LED displays up. No worries that I'll kill my pack by leaving it uncharged for weeks on end.
I bought something else yesterday, which has reinvigorated my enthusiasm to work on the conversion a bit. Well, like any toy, I need an excuse to use it, and I have a motor mount that needs finishing.
This is my latest deal. I love a great deal:
A lightly used Weld-Pak 155. It's a 220v, wire-feed/MIG welder. Set up for gas-less/flux core welding, but it is not difficult to convert to proper gas-shielded MIG. Has the greater part of a 11lb spool of flux core in it (they aren't cheap). Cost me about $150 Canadian.
I say about, because I cut the guy a deal and had him include a 50' 10/3 welder extension cord with it. And a 11lb spool of regular (non-flux core) welding wire:
Guy was retiring/downsizing, hence the good price and light use. I was lucky to be the first one there, particularly since I hadn't put a lot of effort in to it! Maybe the flux-core bit was enough to scare off most people, when they see the price of a conversion kit, which is like $200.
I'll be buying the few pieces I don't have already off of ebay and the like, and should be able to run gas for like $50. Except I'll need another bottle, since the pure argon with my TIG isn't so good for steel MIG welding. I'll have to be patient to find a deal on one.
OTOH, I'm curious to see how it will run if I leave the flux-core wire in,
and add the pure argon to cut down on spatter. Weld quality will probably depend on just what gasses are emitted by the flux. If it'll save me the bother/cost of finding a second bottle, and won't ruin the welds, I'll be satisfied.
So, yeah, I'll start up on this project again soon, if for no other reason then to play with the welder!
