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bill_fimm
12-18-2017, 06:32 PM
Is the Panasonic 18650 10 amp battery here in the store sufficient to power a Neopixel blade? I have read a few places where people say you need a 15 amp. I would like to get some opinions. Thank you.

Tom Tilmon
12-18-2017, 06:53 PM
I believe that one will work fine. I have done all of my bench testing with a 10 amp 18650. Run time a lot less than tricree though. I'm building my Kylo Neopixel with a 26650 15 amp PC. I haven't had my strips (double adafruit skinny 140/meter) trip my battery yet with any stock color on Prizm, or lockup, so I'm assuming that is pretty good, since lockup blends all three colors in the Neopixel, and that is when the largest draw occurs.

Tom

Squimboos
12-18-2017, 10:02 PM
I believe that one will work fine. I have done all of my bench testing with a 10 amp 18650. Run time a lot less than tricree though. I'm building my Kylo Neopixel with a 26650 20 amp PC. I haven't had my strips (double adafruit skinny 140/meter) trip my battery yet with any stock color on Prizm, or lockup, so I'm assuming that is pretty good, since lockup blends all three colors in the Neopixel, and that is when the largest draw occurs.

Tom

Question regarding this actually. The battery is rated at 10 amps, but jst connectors absolutely are not, at least as far as I can tell from reading about them. Will I have to pop an ec3 on that badboy? Maybe a micro Dean? Or is the jst safe?

jbkuma
12-19-2017, 07:15 AM
I've been building these blades for two years using 10amp batteries. The published max current is 60ma @ 5v, for an 18650 it shouldn't be that high. You can read a nicely prepared report here which characterizes the current over the discharge range: https://github.com/Protonerd/DIYino/blob/master/Neopixels_Characterisation_report1.pdf

I never checked the rating on the JSTs, which seem to be 3A. I've mostly hard wired my batteries, so I can't really say too much about that. I think a lot of people may be under sizing their wiring as well. Even if we don't expect to hit the maximum load, we should certainly design for it in order to prevent any sort of thermal event.

Tom Tilmon
12-19-2017, 08:58 AM
I am using way heavier gauge wire than I would normally use to wire an LED. I don't use JST connectors, I directly connect as well. I guess we're all about to be crash test dummies over the long run, but all the guys that have been building string Neopixel blades and strips have been running them for quite awhile now. I haven't seen many major issues (except for reduced run times) reported.

Tom

bill_fimm
12-19-2017, 02:22 PM
Thats good to know. I have some 22 AWG I planned on using. What about the Switchcraft recharge port thats available in the store? What is the max current rating on that? Would that be safe to use?

Strydur
12-19-2017, 04:49 PM
I never considered the current rating of the JST.. According to the specs with 24 gauge wire it is only rated at 2A and with 26 gauge wire 1A. A quick google search shows a lot of people have ran them at 10A or more with no problems while others warn against doing it. Obviously in the saber world customers have drawn a lot more than the ratings and I have never heard of anyone having a issue. That said, for neopixel, I would probably hard wire it.

Tom Tilmon
12-19-2017, 07:55 PM
Thats good to know. I have some 22 AWG I planned on using. What about the Switchcraft recharge port thats available in the store? What is the max current rating on that? Would that be safe to use?

The most draw will be negative from blade to board.

I don't know what the RC Port rating is, but the positive pin will take the most juice there. One of the board manufacturers was so concerned about Neopixel draw on the ground, he widened his ground within the board to carry more juice. Hard wire your battery. I'll look into the rating on the Switchcraft RC Port, but many of the guys that have been doing these have been running fine off the normal stuff.

Tom

bill_fimm
12-20-2017, 05:15 AM
The most draw will be negative from blade to board.

I don't know what the RC Port rating is, but the positive pin will take the most juice there. One of the board manufacturers was so concerned about Neopixel draw on the ground, he widened his ground within the board to carry more juice. Hard wire your battery. I'll look into the rating on the Switchcraft RC Port, but many of the guys that have been doing these have been running fine off the normal stuff.

Tom

Hard wired meaning through the recharge port as in the Plecter manual? Thank you for your reply. I am new to this hobby and just want to make sure I am doing this safe.

Tom Tilmon
12-20-2017, 09:04 AM
Yes. Though RC Port. Here is the rating on their dc charging ports:

https://i.imgur.com/ZhjkaN5.jpg

5amps rated. If one of the tabs on RC port were to give way and melt (which I doubt), I'd rather a failure occur there. The boards are also carrying the load. The internal traces on the board are much thinner than the legs on the port. I believe that industry, for their safety must underestimate rating, and over-estimate draw of components. That and the neopixels strips ideally run at higher voltage than most of us are actually using in them. We are using lower voltage.

I still think the biggest issue/change with neopixels will be the MAH. They will eat a lot of juice quicker than in-hilt LEDs. IMO that will be the big change.

Tom

Strydur
12-20-2017, 09:47 AM
Correct, Amperage ratings are often quite under rated.

bill_fimm
12-20-2017, 10:57 AM
Yes. Though RC Port. Here is the rating on their dc charging ports:

https://i.imgur.com/ZhjkaN5.jpg

5amps rated. If one of the tabs on RC port were to give way and melt (which I doubt), I'd rather a failure occur there. The boards are also carrying the load. The internal traces on the board are much thinner than the legs on the port. I believe that industry, for their safety must underestimate rating, and over-estimate draw of components. That and the neopixels strips ideally run at higher voltage than most of us are actually using in them. We are using lower voltage.

I still think the biggest issue/change with neopixels will be the MAH. They will eat a lot of juice quicker than in-hilt LEDs. IMO that will be the big change.

Tom

Thanks for the reply Tom. If the worse case would be the port melting, like you said is not likely, thats cool. Iíll give that recharge port a shot. Since I am new to this hobby I really donít know much. I would just be afraid if you said something like it could cause the battery to blow up or something. Thanks again sir.

Jacobpac
12-20-2017, 07:38 PM
Anyone have an approximate run time for the Panasonic 18650 3.7v 10 battery for a neo pixel blade?

Forgetful Jedi Knight
12-20-2017, 07:47 PM
From what Iíve been advised, itís about 35-45 minutes.

Tom Tilmon
12-20-2017, 08:21 PM
If you hit a load that high, with the thin traces on these sound boards, I'd suspect you'd fry a soundboard first, and the saber would shut off. None of the many who have already made these sabers are experiencing that, and neopixels have been around in saber usage now for over a year. But now TCSS has brought a simple socket solution to the masses, so we shall see how this goes. I think we'll be fine. I'm proceeding on as planned.

Tom

bill_fimm
12-21-2017, 07:12 AM
Thank you for the info everyone. I appreciate the help.

jbkuma
12-21-2017, 09:43 AM
Your run time will vary greatly by your color. If you think of it like three 4amp LEDs (approximately) instead of three 1amp LEDs of a Cree you'll get an idea. Your battery will last about 1/4 the ignited blade time you would get from a tri-cree setup with the same color combinations.

If you are running just one color (red, green or blue) fully on it will run about 3 times longer than if you have all three fully on (white). For a single color: 3200mah / 4amps = about .8 hours, or 48 minutes. Things are a bit more complicated than this since the saber isn't going to run properly over the full discharge curve of the battery and there other effects at play. In the real world, depending on your color combinations, you'll probably get around 30 minutes of illuminated blade time.