Hi,
This isn't rocket science but I've put together a little battery pack for the R3 and I am going to try to upload 6 pics in the "download" section. The steps correspond to the pictures but hopefully you can still follow along even if the pics aren't up right away.
1) there are three parts: a battery holder for 8 aa batteries with a 9 v clip terminal on top (radio shack $2), a 9 v clip terminal with leads (radio shack $2), and a power plug to plug into the R3. I believe the correct terminology for the power plug is a "Barrel connector 5 mm OD x 3.5 mm ID with center pin". You can google these words to order one, I found one attached to an old wall wart.
2) I plugged my korg power supply into the wall and measured the inner pin to outer sleeve voltage as 12.32 v.
3) I soldered the barrel connector leads to the 9 v clip terminal.
4) I inserted 8 aa alkaline batteries into the holder, and measured the voltage as 13.09 v.
5) The battery pack is plugged into the R3 and it works.
6) The battery pack clamped to the side of the R3, very inelegant but the height of the battery pack is nearly the same as the rear of the R3.
Some comments:
I did this to see if it can be done with my purpose being to take the R3 into the tv room, sit on the couch and use headphones. It would be nice to have a way to secure the battery pack to the R3 and there are lots of phillips screws which could be used I suppose. If anyone knows of why 13.09 V may be dangerous to the hardware since it is more than 12.32 V please speak up. If I wind up using this a lot it would make sense to use rechargeable batteries but that might change the voltage. If you want something like this to gig with I came across a $20 miniature 12 v lead acid battery from BatteriesPlus (Werker 12 V 1.3 AH) which would most likely be a much better, more reliable solution.
Cheers!
Battery Pack for R3
Moderators: Sharp, X-Trade, Pepperpotty, karmathanever
Battery Pack for R3
Owner of R3, nanokey, and Kaossilator- and some guitars.
While the battery voltage may be higher at start, you should measure the voltage under load to get an accurate reading when powering the R3. That's because batteries aren't a single voltage - they have voltage curve based on load and temperature. Different battery chemistry also have different voltage curves.
Because of the battery voltage curve, using a DC-DC regulator (with current limiter) and a battery pack that supplies a higher voltage to the regulator is a better approach to supply a constant DC voltage to the R3. It will also allow you to use batteries with different chemistry, akaline, NiMH, SLA, and NiCd, and give longer life by adding a cell or two to the battery pack. This kind of regulator is very cheap and relatively easy to create, since it only requires one power transistor/FET, a zener diode, and a few resistors and caps.
Once you build it, the same one should work for the R3, MicroX, X50, and KP3.
Because of the battery voltage curve, using a DC-DC regulator (with current limiter) and a battery pack that supplies a higher voltage to the regulator is a better approach to supply a constant DC voltage to the R3. It will also allow you to use batteries with different chemistry, akaline, NiMH, SLA, and NiCd, and give longer life by adding a cell or two to the battery pack. This kind of regulator is very cheap and relatively easy to create, since it only requires one power transistor/FET, a zener diode, and a few resistors and caps.
Once you build it, the same one should work for the R3, MicroX, X50, and KP3.