Looking for high amperage (5 A?) mobile power solutions.

Stuart_Sands · August 5, 2018, 4:28pm

Looking for high amperage (5 A?) mobile power solutions.
I’ve got a mobile LED using project using FastLED (mobile as in people being lit up), and some of the costumes require more than 2A. The library is great and I’m really happy coding with it.
I’d be comfortable with 5A and am wondering what solutions people have come up with. I could try multiple cell phone chargers, but also wanted to know if there were other battery options out there. It’s gotta be worn, probably on a belt or perhaps stashed down a pocket.
Thanks in advance!

Jeremy_Spencer · August 5, 2018, 8:16pm

I use either 18650s or lithium polymer batteries on my wearable projects.

Do you mean 5A draw or 5A hours??

I use a 5Ah battery in my hat with about 300 LEDs.

Stuart_Sands · August 5, 2018, 10:45pm

@Jeremy_Spencer thanks. 5 amps. I’m “overengineering” a bit to be on safe side. I think i mught be able to get by with less. I need to learn about thise 18650s. Seems like i need to create voltage divider for the correct voltage. Is that what you’ve done?

Leon_Yuhanov · August 6, 2018, 2:14am

I use these https://hobbyking.com/en_us/yep-20a-hv-2-12s-sbec-w-selectable-voltage-output.html?___store=en_us in conjunction with any number of 18650s

Jeremy_Spencer · August 6, 2018, 5:40am

@Stuart_Sands I use the native voltage from the batteries, I don’t boost it or divide it or use a level shifter. You need to test this with your LEDs and MCU… I use ESP8266s and ESP32s with SK9822s.

Watch out for fake batteries claiming greater capacities than possible. As far as I’m aware it’s not possible to make an 18650 which holds more than 3600 mAh… Some vendors claim 9900 mAh!!!

Stuart_Sands · August 7, 2018, 6:52am

@Jeremy_Spencer , thank you, I’m using an esp8266 for this project and apa102c strips. Good to know, thank you.

Stuart_Sands · August 7, 2018, 6:54am

@Leon_Yuhanov Wow, I never heard of those. I’m doing this for Burning Man so not sure how much time I have left for this, but another item I want to check out. Thanks. I need to learn more about those batteries.

Robert_Atkins · August 12, 2018, 9:02pm

You can use multiple USB power banks. Split the positive rail in two (or three…) and connect each section to an individual power bank. Tie all the grounds together.

Leon_Yuhanov · August 12, 2018, 11:24pm

@Robert_Atkins Rob ill miss you at Seed this year

Marc_MERLIN · August 14, 2018, 10:10pm

http://marc.merlins.org/perso/arduino/post_2018-05-29_EDM-Party-Shirt-powered-with-FastLED_NeoMatrix-and-Adafruit_GFX_-plus-160Wh-10Ah-4S-worth-of-lipos.html shows the 10A 5V DC-DC converter I use. You can give it any lipo voltage on in, it’ll output 5V up to 10A on out. Easy peasy.
That’s the converter I’m using: https://www.amazon.com/gp/product/B00J3MHTYG
Sure, using USB battery packs mostly works too, but I prefer using lipos because I can charge them at very high speed (1h) while big USB battery packs can take 12H or more to charge

Leon_Yuhanov · August 15, 2018, 1:46am

@Marc_MERLIN Marc does that thing get HOT during use?

Marc_MERLIN · August 15, 2018, 2:15am

@Leon_Yuhanov it does not get hot at all, that’s why I took a big one (well, it’s not that big, but you you know what I mean).
Before I used a BEC from my RC planes

Allegedly it supports 10A too, but

it’s designed for having airflow in a moving RC aircraft
it’s not actually meant to run at 10A continuous
It did get uncomfortably hot at 10A and I did not care to find out how long it could maintain that draw
To be fair my shirt only uses 2-3A at most because if I make it brighter (and draw more current), it also blinds people but I figured I could use a bit more space and a bigger step down converter, so I got a bigger one that can dissipate the heat better.
The only problem with it is that when it uses 10A on the 5V side, it uses way more amps than it should on the other side, but if you stay below 10A (even 9.5A is ok), it does fine and seems efficient enough.