Topic: Walmart LiON, V3, so many questions...

[silverbullet]

>>I think the extra time spent soddering pays off. I used some shielded audio cable, cut it and used Radio Shack item numbers 274-1568C & 274-1532.<<

why not just solder a 4 pin xlr onto the walmart battery cable?  then you can use it with your existing (and locking) v3  connector to 4 pin power cable.  just connect the 2 4 pin xlrs...

I did look for a four pin female xlr in Radio Shack but I couldn't find one. That was an option I did consider but to reduce wires I still like having just the right length cord. One less thing to get tangled up. If I have any problems with this setup then I'll inform this thread.

follow up photo from last Saturday. Incredible how small the V3 is IMO. Wal-mart battery on top of the V3. Looks like they were made for each other. I probably will put velcro between them.

the optical cable I got from www.soundprofessionals.com optical cable to right angle TOS link. No adapters. Just wish the wire was shorter but that's just me and wires. I'm a minimalist and a bad speller.

[silverbullet]

I emailed Grace asking about the Walmart battery question. Here was my reply....

______________________________________________

I just received my new 6volt V3 from Colorado. thanks.

I see some folks using a WalMart DVD rechargable 5400mAh/9v battery with their V3's. Is this safe to use with my 6volt V3?

thanks,

Tim

__________________________________________

Hi Tim-

Glad to hear you received your V3!  As you probably know, the V3 has two
settings that can be calibrated based on DC operating voltage.

The first of which is the low battery indicator.  This is set to engage
at 5.75V for 6V operation or 11.5V for 12V.  These voltage thresholds
provide an indicator that will engage with approx. 45 minutes to 1 hour
of runtime remaining and are based on sealed lead-acid discharge
characteristics.

The second adjustable DC parameter is the auto-shutdown circuitry
threshold.  Over-discharge of a sealed lead-acid battery will
permanently damage the cells.  To prevent this, the V3 will turn off at
the given threshold and will not turn back on until the battery has been
disconnected and reconnected.  For 6V operation this voltage is set to
5.0V and for 12V it is placed at 10.0V.  Again these values are based on
the sealed lead-acid discharge curve.

Now to address your questions directly:

> Is there any problem running the V3 with a 9.0V source? 

There is no problem running the V3 from 9.0VDC.  The higher the voltage
you run the preamp on, the warmer it will run.  Given the calibration
settings of your V3 (6V) you can run it as-is.  If your unit was set for
12V you would not be able to run it off this battery - the DC input
voltage would never exceed the auto-shutdown voltage and the preamp
would not power up (or would power on momentarily and then shutoff).
With this setting however, you will not have low battery indication or
auto-shutdown facilities available.

Depending on the type of cells this 'dvd' battery utilizes, you may be
able to recalibrate the V3's low-batt and auto-shutdown voltages to
match its discharge characteristics.  To do so you will need an accurate
voltmeter and variable DC power supply would make it easier.  To
reiterate, you do not need to recalibrate the V3, you just won't be able
to use these functions.

It is critical if you wire your own battery to connect the positive to
be to the internal opening and the negative to the external outer shroud
of the DC barrel connector the plugs into the V3.  Failure to observe
this proper polarity will cause damage to the V3.

--
Jamie Krapohl
Assistant Design Engineer
Grace Design & Lunatec LLC

____________________________________________________

Hi Tim-

Thanks for sending us the link.  Looks like a nice power option, and
convenient form-factor.  Nice work!

Tim Younkin wrote:

> thought you might like to see this image
>
> http://www.seaofsouls.net/mbp/V3wire.jpg
>
> thanks for your prior input
>
> Tim
>

--
Jamie Krapohl
Assistant Design Engineer
Grace Design & Lunatec LLC

[silverbullet]

the V3 is a size "M" - although the connection to the V3 is not very tight.  It does work though.  I'm going to try to rig up something better soon, but this will have to work in the meantime.

I went to RS again today. Picked up a size M and L (#274-1568c) connector to compare the two with the V3 connector. The size L looks to be the better fit. As you stated the size M does work but not very tight. To my eye the size M looks a little bit smaller than it should be. I'm returning the size M connectors tomorrow. I'm happy with my size L fitting into the V3

[silverbullet]

why don't you use the switchcraft part# S760K, that is designed for the connection?
voltage spikes from loose connectors aren't good.

Because I didn't know about switchcraft part#S760K. Now I do. Thanks. Back to the drawing board. 

[scb]

i just picked one up from wal mart.

i soldered a 4 pin onto the included cable and wired it like a 12v (so if i plug it into stuff wanting ONLY 6v it won't fry it)

gonna test it with a ULN2 and with the mytek box. 

[John Kelly]

i just picked one up from wal mart.

i soldered a 4 pin onto the included cable and wired it like a 12v (so if i plug it into stuff wanting ONLY 6v it won't fry it)

gonna test it with a ULN2 and with the mytek box. 

Definitely post results with the ULN2.  I know Matt is interested in new power options...

[Brian]

not to hijack this sweet thread but eveytime you guys post an email from Grace Designs support it just reaffirms that they are one of the most professional and straight up bad-ass businesses around!

Brian

[scb]

plugged into the ULN2 and power kept switching on and off.  i guess it's not enough juice?  i'll try again after work just to make sure i'm not crazy

[silverbullet]

Is that a 12v you are hooking up to? Grace said that 9volt battery would not work on their 12 volt unit. Probably true with other equipment needed 12volts. Not enough juice. read the email I posted above.

[scb]

the ULN2 needs 9 or higher, so it should have worked.  i wonder what the actual voltage on this lithium is

[silverbullet]

i wonder what the actual voltage on this lithium is

I checked with my voltmeter. Even at 3/4th charge it's still putting out 9.1 volts.

[scb]

then i wonder what the ULN2 really needs.  the back of it says >= 9V

[silverbullet]

hmmm. maybe it has something to do with amps? amperes (spelling?)

[dklein]

are your wires thick enough?  That sucker needs 1.4 A at 9v - very hungry.

[MattD]

hmmm. maybe it has something to do with amps? amperes (spelling?)

B.J. (Metric Halo's technical know-it-all) said it had to do with the battery likely being current-limiting. The ULN-2 requires 0.8W, so I'm guessing this battery cannot put that out at 9V. I'd be curious if 2 in either series (ULN-2 can handle 9-24V) or parallel would reduce the strain on any one battery enough so that this would work.

John, I need to figure out if I can connect a 4-pin XLR or an adaptaplug to that ncharge or powerpad you have. That'd drop my bag weight by about 10 pounds if it works.