Contactor circuit blowing fuses

[amberwolf]

Great explanation! Who knew the lowly light bulb was so unique and versatile! Is there an electronic equivalent I wonder?

Sort of; they call them inrush current limiters (ICR). But they start out with a high resistance, and then get lower as they get hotter. They use them on some SMPS power supplies and chargers with large capacitors, so you don't blow the fuse or breaker on the outlet when you turn them on. They are also called NTC thermistors.

There are also PTC thermistors, which increase resistance with temperature. Small versions of these are sometimes used in small battery packs, as a self-resetting breaker of sorts. THe Cycle Analyst has one on it's batt+ outlet connector. Many motherboards I've seen have them on each of the USB ports on the +5V line.

I just don't know if there are any that can handle higher currents--but there's a lot of incandescent light bulbs out there that do, and most people have at least one they can spare already at their house while troubleshooting.

 

[amberwolf]

The seem relatively ok. YOu'd have to check the manufacturer's charts to see if your results match theirs at the various points especially the discharge voltage sag.

But they are all about the same, so they're at least all in the same state (balanced well enough).


If none of the batteries was actually down to 9V when you pulled them out (55 / 6 = 9.16) then I'd say your problem really lies somewhere else, like the connections--anything in the series connections between them, or their connnections to the trike, or between those and the actual loads in the trike. That's probably a fair number of points to test, but you can test them as described in the post above:

https://endless-sphere.com/forums/viewtopic.php?p=1401664#p1401470

 

[cboy]

Update on progress...
After a couple days off catching up on other household chores I got back to the battery situation. I put the charged and tested batteries back on the trike, wired them up and then re-installed all the other electronics, testing along the way for drains or possible shorts. Everything went together pretty well except one small gremlin in the left rear turn signal wiring that had somehow gotten shorted. Not sure what it was but took it apart and put back together a few times and suddenly it worked fine. Which means the problem, if it was a loose wire, might pop up again. But I can't replicate it by jiggling things around so I'm hoping for the best.

When all the wiring was back together the controllers and motors fired up without a hitch. I did put on the new contactor from Kelly but as amberwolf noted, it probably wasn't the problem. The new contactor relay tested out with the exact same resistance as the old one, about 289 ohms. The only thing I did different was to run the ground from the contactor relay directly to the system ground rather than running it into the ground pins of Kelly controllers. I don't really know if the Kelly ground pin was somehow at fault (it simply connects to system ground within the controller) but it seems unlikely to me. I suppose I could wire the ground to the controller again and run a test just to see if it blows a fuse. Perhaps in a day or two if I feel adventuresome.

Bottom line, all seems well at this point. Went out for a short test run this afternoon and all systems seem to be performing well. I'm still a little concerned by the total charge my batteries appear to be accepting and holding but I want to log some major test miles and get some good CA3 gauge readings along the way so I can report accurate data if I still have concerns. But that is really a separate topic and I'll probably start a new thread if there are issues.

So just want to pass along a huge thank you to all who contributed opinions, troubleshooting tests and possible solutions in response to this post...especially amberwolf. I'd be lost without the knowledgeable folks who hang out here.

 

[fechter]

The battery voltages look pretty normal to me.