Beginner Question Thread! 2023 Edition

Well I don’t think that it’s possible to spot undercharged cells (below 2.5V) anymore since it was already on the charger for a while. So I don’t think there is much going on that we would be able to see by opening it up. Unless the issue is broken wiring, which I doubt since Acido is a great builder, but nevertheless that can still be spotted if the pack starts balancing itself out on the charger but stops before finishing. So not reaching 41.5V or so ultimately.

EDIT: I also doubt that there are any overcharged cells in the pack, since the BMS did stop charging at 36.8V.

Can you do this without removing p group nickel? Or do just mean the voltages or each p group?

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I think Al means P group voltages.

You can check connectivity between the same polarity cell terminals in the P group though, at least if the nickel that was used isn’t wide enough to cover up the terminal completely. If the connectivity is flawless everywhere (resistance is very low, unmeasurably low with cheap multimeters), all cells within the P group must be at the same voltage. The only way that a cell could be at a different voltage than the rest of the P group is if the nickel doesn’t make good contact.

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So if there’s fully and less charged cells, the charger will stop charging because it detects full charged cells? And the BMS will register that the cells are not equally charged and level them out slow but steadily?

This is how it works:

The charger is dumb, it can’t switch off. When you reach 4.2-4.25V in the highest voltage cell, the BMS disconnects the charger, and it knows that the highest voltage cell is a little overcharged, so it connects a tiny load to it. This a resistor inside the BMS. This very slowly discharges the high cell, until the voltage gets low enough - typically 0.05-0.1V below where the charger was disconnected. The BMS does this to all cells that are considered overcharged. At this point, the BMS connects the charger again, and charges all cells until the highest one reaches the cutoff point, 4.2-4.25V. The slowly discharges the higher voltage cells.

This cycle continues, until all cell voltages are very close to each other. When this process finishes, all cells should be fully charged, typically between 4.15-4.2V.

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I agree, I was hoping to learn a magical new trick :disappointed:

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is there any way to “reverse” a ppm remote? with the case mod I’m using the old “backwards” is what I now want “forwards” to be and vice-versa. can I just invert it in software like with the motors? I could just use current bidirectional but I really want hyst reverse with the right throttle orientation.

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Swap the potentiometer leads inside the remote. I think it’s the outer two on the Mini & GT2B

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You know of any good non brittle epoxy? Gonna put some epoxy around the potentiometer and over the solder joints in the hoyt puck.

search is useless, does anyone have the measurements for kegel pins? or a SLDPRT file for the kegel wheel mount standard?

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It’s a poor carpenter who blames his tools

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Thank you! This’ll be very helpful!

This is a “medium” epoxy I’ve used for a long time. It’s hard but not as brittle as many. Silicone RTV (electronics grade) can work better for strain relief of wires.

[Later edit] But it can wick under and into things, perhaps into places you don’t want it to go, so it might not be a good choice.

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I need it to be really rigid, but not brittle. Whole point is to not let the potentiometer or solders move at all.

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According to project farm, original JB is the strongest epoxy from the ones he tested.

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Surprise! It’s jb weld. Always.

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Yup, I mentioned it is hard (80D). :slightly_smiling_face:
I haven’t had any problems with it being too brittle. I use it for affixing heavier components to circuit boards (beepers, inductors, etc.) and have never had one crack off. With enough force though you can, of course, cause it to break.

I recommend going crazy with making sure you have a true 1:1 ratio when mixing as IMO most problems (not hard enough or too brittle) come from too little or too much hardener when mixing.

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Thanks. This helps alot. Gonna look if i can find this product here in the north. :smiley:

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Leave it somewhere warm for at least 24 hours so it cures fully. In a cold room it takes a lot longer to get full hard.

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Can’t find any ir scanners
Anyone know if I can use a phone as one?

Either way I heated for a minute and a half (the entire motor got hot) and the bolt still won’t budge

Is there a way to completely remove the bolt (destroy it)