How do you power a paca(rana) from batteries?

Question

I want to take my paca into a forest to do a performance. Which means I'll want to power it by batteries. Has anyone tried to do this?

Myself and my collaborator-in-noise, Tom, have successfully made a battery powered eurorack modular with a bit of basic soldering and a DC-DC converter. We were powering 7 modules off a small 12V NiMH battery pack (on top of a hill, at night with no moon and a speaker suspended from a tree).

I want to try this with Kyma now. How much power does a paca use? The paca seems stateless, meaning it doesn't appear to save any kind of state between power cycles, does it? Would anything go disasterously wrong with the paca if the power failed? I'm guessing it doesn't generally write to its storage except during a firmware upgrade?

What would be the pitfalls to watch out for?

Answer 1

Hi!

I just finished doing a performance project with a group where we travelled 160km downstream on a river with a 12m rowing boat.

I had a setup for the perfomance that included 500W+500W amp+speakers, Paca, computer etc... everything was powered by a 12v 100mAh battery (not a car battery, but one that is made for campers and holiday cabins)+700W pure sinewave power inverter and it worked flawlessly. I could run the setup at least through a rehearsal day for 8 hours, but I never tested the total amount of hours that the system could run for. 100Ah is overkill for the system and I think 50-60Ah could have been enough.

The system cost me around 500€ with a charger. I would recommend one. It seemed very stable and easy to use.

I believe it's very hard to calculate the amount of electricity a sound system needs. The most accurate would be to use watt-hour meter and then convert the watt-hours to ampere-hours for an estimated battery capacity.

Comments

Thanks for you answer! That's really interesting. 100Ah battery has got to weigh a bit I'm guessing?

Presumably it would be less efficient to go from a 12v battery through a pure sinewave inverter to then convert through the paca's power supply back to DC again. I was looking to make something lighter but it's really good to hear that worked for you. I do happen to have a pure sinewave inverter and a deep cycle battery (that weighs 35 kg!).

I might pursue the DC-DC converter route. We got this to work for a small eurorack modular from a small pack of 20 * NiMH C cells. So not very heavy at all. I'm guessing 1 - 1.5kg. And that ran the 50W amp and 15" speaker too for a couple of hours and didn't run out.

Your performance sounds fantastic! Nice one.

Answer 2

Here's my paca running off a 12v battery, without an inverter!

 

I've just finished soldering up a DC-DC converter. I'll bring it along to KISS2018 if you're there and want to see it. It's based on the Murata UWE-12/10-Q12PB-C... "based on".. ok it "is" the Murata UWE. There's not much more to it apart from wires, solder and a small plastic box. The tricky part is soldering the 4 pin din power plug for the paca. (Caveat, don't know if this will be enough to power a Pacarana. There's not a huge amount of power headroom.) I've just finished this so not field tested it properly yet.

 

(It's only taken me a year)