Legality of running a capacitor inline with roboRIO power

[EricH]

Originally Posted by Ether

Follow Mike's advice about your wiring, even though you think it is "100% correct and pristine".

At the risk of getting another "Unnecessary Sarcasm Flag" thrown, I agree with this. This is CS101 Syndrome: "It's perfect, I did it!" Guess it applies to electrical as well... Get someone who isn't familiar with your wiring to examine it if you can. They'll be more able to find the problem easily than you are, because they don't think "Oh, that's normal" on something that might not be right.

[ImOn3618]

Originally Posted by Daniel_LaFleur

I suspect that your battery is low and you are using a high traction drive train with an incorrect gear ratio.

We have a rigorous standard for competition batteries, and start each machine with a fresh, fully charged battery, so I doubt that's the issue.

However, we have a very high traction drive train (brecoflex treads with about a 1.5 CoF, 750ish N force of kinetic friction while driving). The gear ratio on the drive belts is 14.2:1 using RAWboxes. While the drive train definitely contributes to our issue, there's not much we can do about it with 6hours of unbag time.

[ImOn3618]

Originally Posted by EricH

Get someone who isn't familiar with your wiring to examine it if you can.

Guess it's worth a shot

[MrBasse]

Originally Posted by ImOn3618

We have a rigorous standard for competition batteries, and start each machine with a fresh, fully charged battery, so I doubt that's the issue.

However, we have a very high traction drive train (brecoflex treads with about a 1.5 CoF, 750ish N force of kinetic friction while driving). The gear ratio on the drive belts is 14.2:1 using RAWboxes. While the drive train definitely contributes to our issue, there's not much we can do about it with 6hours of unbag time.

Beyond just charging them, do you do any tests on them to gauge the batteries overall health?

[ImOn3618]

Originally Posted by Daniel_LaFleur

I suspect that your battery is low and you are using a high traction drive train with an incorrect gear ratio.

Was off on my math/material type. It's actually .7CoF, 370N force of traction

[ImOn3618]

Originally Posted by MrBasse

Beyond just charging them, do you do any tests on them to gauge the batteries overall health?

We track and compile data from a battery beak, including power output, drain rate, and changes in amperage at various voltages. If they get below a certain threshold we stop using that battery and recycle it. We've also used FRC2619's battery maintenance guide in the past.

[Kevin Sevcik]

Originally Posted by ImOn3618

We have a rigorous standard for competition batteries, and start each machine with a fresh, fully charged battery, so I doubt that's the issue.

However, we have a very high traction drive train (brecoflex treads with about a 1.5 CoF, 750ish N force of kinetic friction while driving). The gear ratio on the drive belts is 14.2:1 using RAWboxes. While the drive train definitely contributes to our issue, there's not much we can do about it with 6hours of unbag time.

Gear ratio only barely matters. What's your theoretical top speed, assuming 5400 RPM input?

I agree with Mike that your issue could be a bad connection somewhere between the battery plug and the PDP, on either the positive or negative leg. Double check every single connection starting from the battery plug. Check for corrosion or a bad crimp. If a ring terminal looks looks dull or corroded, either replace it or hit it with a wire brush till it's shiny. Check the contacts in your main battery connector for corrosion as well. You might also try replacing your 120 Amp Main Breaker with a new one. Main breakers can occasionally have weird issues.

[MrBasse]

Originally Posted by ImOn3618

We track and compile data from a battery beak, including power output, drain rate, and changes in amperage at various voltages. If they get below a certain threshold we stop using that battery and recycle it. We've also used FRC2619's battery maintenance guide in the past.

That's good, should rule out a bad battery. There is a really easy solution to this problem: don't change direction really quickly.train your drivers to not do it anymore and you won't do it anymore.

[ImOn3618]

Originally Posted by Kevin Sevcik

Gear ratio only barely matters. What's your theoretical top speed, assuming 5400 RPM input?

About 4.75ft/sec.

[Ether]

Originally Posted by ImOn3618

...drain rate...

What are the units of "drain rate" and how do you measure it?

[ImOn3618]

It's just power output compared to ℅ battery charge. We use it to get a rough idea of how fast our batteries are being drained. Older, worse batteries tend to lose charge faster.

Theoretically, loss of 30℅ charge from 100% is normal for us. So about 12.5v to 8.75v per match, according to our multimeters

[Ether]

Originally Posted by ImOn3618

It's just power output compared to ℅ battery charge.

I'm still puzzling how you measure this. How do you measure power?

[ImOn3618]

It's voltage, not power(joules), my bad.

[Kevin Sevcik]

Originally Posted by ImOn3618

About 4.75ft/sec.

4.75, or 14.75? 4.75 seems unreasonably slow. Like, low gear in a two-speed slow. I'm having difficulty believing you're browning out turning or pushing at 4.75 fps, unless you have serious drivetrain issues. I guess the other question is what your current draw is when you're running full forward with the treads off the ground.

[ImOn3618]

Originally Posted by Kevin Sevcik

4.75, or 14.75? 4.75 seems unreasonably slow. Like, low gear in a two-speed slow. I'm having difficulty believing you're browning out turning or pushing at 4.75 fps, unless you have serious drivetrain issues. I guess the other question is what your current draw is when you're running full forward with the treads off the ground.

We're *really slow*, decided on pushing power early on. I'll get the current draw ASAP.