how to convert AC device to run on Battery?

Thread Starter

audiomike

Joined Jun 6, 2022
8
Hello all, I am new here. I am a PC repair tech and not all that familiar with AC/DC so please bear with me.

I bought this Korg kaoss pad and would like to have it run on batteries instead of AC power:

Mod: Link deleted..E

The specs show Power Supply DC9V 1700mA

I know a couple Electricians in my circles, not electronics techs so I am checking here first to hear what you guys might have to say before I should go contacting any local person here. So my question guys is can this safely be done without risking messing up anything at all? If yes, what exactly would need to be done please? Thanks.
 
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BobTPH

Joined Jun 5, 2013
5,227
It is DC powered, at 9V. You can supply that with an AC adapter, battery or a water wheel, as long as it provides 9V at at least 1700mS.

Bob
 

Thread Starter

audiomike

Joined Jun 6, 2022
8
Thanks bob but sorry not clear on the terminology as it comes with this AC Adapter.Screen Shot 2022-06-06 at 8.30.22 AM.png

DC 9v suggested to me that is can run on one of those rectangular 9v batteries, is this correct please? The manual does not mention anything about DC, this is what it is shows:
Power supply
Please connect the designated AC adapter to an AC outlet of the correct voltage. Do not con- nect it to an AC outlet of voltage other than that for which your unit is intended.
 

LowQCab

Joined Nov 6, 2012
2,170
1700ma is 1.7-Amps,
which equates to ~15-Watts,
a single 9-Volt Battery can not produce 1.7-Amps on its best day.

That's a Big-Fat Power-Supply,
and You have a "Power-Hungry-Device",
Battery operation is not very practical at this Power-Level,
unless You would find it practical to tote-around a ~5-pound, 12-Volt, SLA-type-Battery,
and build a Voltage-Regulator for it.
.
.
.
 

BobTPH

Joined Jun 5, 2013
5,227
Thanks bob but sorry not clear on the terminology as it comes with this AC Adapter.View attachment 268854

DC 9v suggested to me that is can run on one of those rectangular 9v batteries, is this correct please? The manual does not mention anything about DC, this is what it is shows:
Power supply
Please connect the designated AC adapter to an AC outlet of the correct voltage. Do not con- nect it to an AC outlet of voltage other than that for which your unit is intended.
What is important is what comes out of that power supply, I.e., 9V. To run it off a battery, you would not use the AC adapter. You would connect your DC 9V source to a plug identical to the one coming out of the adapter and plug that into the power jack on the tablet.

A small 9V battery is not sufficient. Your best bet would be a lithium battery. It would run fine off 3 18650 cells in series and a 9V switching regulator. You might even find a power bank already constructed that can supply 9V at that current.

Bob
 

Irving

Joined Jan 30, 2016
2,769
Battery operation is not very practical at this Power-Level,
Rubbish - a battery solution is possible but you need to be realistic about run-times.

A 11.1v LiPo battery like this:

1654520541301.png

is 25 x 47 x 140mm (1" x 2" x 6" approx) and weighs 320g (13oz)

With a small external regulator it will give you better than 2h run time, two in parallel will give near 5h.

EDIT: A pack of 6 x 4500mA 18650 cells, 3 series, 2 parallel would do, but I'd recommend the pre-built packs.
 

Thread Starter

audiomike

Joined Jun 6, 2022
8
Actually, that is what I was hoping for all along, to use an external battery velcroed unto the sides of the unit. Can I trouble you to link me to a "pre-built pack" or tell me the description of it so I can go looking for one whenever you might have a minute please? To clarify, I don't need the power for continuous use, just to use for a few seconds or so every maybe 15 minutes when I'm hanging out listening to music.
 

Thread Starter

audiomike

Joined Jun 6, 2022
8
I just bought the Korg Kaoss Pad Quad couple days ago, they will ship it out today, I am in New York.

Mod: Deleted link.

I bought this just as a toy to play around with it's effects when I am hanging out listening to music. The unit will need to be powered on for like 4-6 hours but I will only play around with it like every 15 minutes or so. I will be trying to get an adapter device to make it wireless so no need to run physical cables to the Mixer, looking into options for that now but that is why I am seeking to make it battery operated.
 
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BobTPH

Joined Jun 5, 2013
5,227
Thank you so that external will handle the power requirements plus it comes with a charger.

Now, how would I connect it to the unit please or is this something I would to know from Korg?
Yould would need the determine the connector types on both devices and make a cable. Possibly you could buy one. You have to be careful about polarity, as there is no standard. If you were to photograph both jacks, we could help, thenormally show the polarity.

Bob
 

Irving

Joined Jan 30, 2016
2,769
Some further thoughts - audio electronics generally tends to run at full tilt while switched on whether you're using it or not, and as this was designed for AC use its unlikely the digital side has any power-reducing 'sleep' functionality (other than turning itself off after 4h). Having said that, just because the adapter is spec'd at 1700mA doesn't mean it uses that much all the time. So a 5100mA pack should give at least 2.5h+ but could be 3 - 4h - no way to tell until you try it. Adding wi-fi functionality for audio in & out will have similar constraints. So while this can be done, there's a debate to be had whether it should be done!

@BobTPH has linked to a 9v powerbank, but sadly its of no use to you. You have to read the specs carefully - it says 9v @ 1A. This is because the 9v is derived from the 11.1v via a simple linear regulator and is not part of the buck circuit. You need 2A so this output is unlikely to work for you (or if you try it, not for long I guess).

I'm not convinced about its true capacity either. The best similar-sized Turnigy (a well respected RC modelling brand) battery is 190W/kg energy density, this claims to be > 246W/kg.

Your best solution, IMHO, is a custom build. If you want to go that route I can offer some suggestions.
 

Thread Starter

audiomike

Joined Jun 6, 2022
8
Well I am confused now between what you both have stated. However, I am always open to any and all options.

Please note guys that at this point I am seeking only information on the possibility of this so I wouldn't want any of you to spend too much time and effort on this. Reason being, I am trying at the same time to also work on the Audio wireless connection option on other forums which is equally as complicated as this power issue so I am not sure if this will all work out.
 
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