Topic: How to power my jb3 for a weekend (bonnaroo)

[Brian Skalinder]

Let us know how it goes, yemnscu.  I vaguely recall David Klein trying something similar using 4 x 1.2v NiMH rechargables - effectively the same thing as an RC battery.  I *think* he found the voltage a bit too high when fully charged, but that it didn't take much dissipation to bring the voltage down enough to make it operable.   Hmmmmm...maybe I'll try to find it over on the NJB3Tapers group...

[Ed.]

if a 4.8v rc battery will work, can you double or tripple them up so you can switch to another when the first one starts to die?  kinda like you can with the ua-5?

ed

[Brian Skalinder]

if a 4.8v rc battery will work, can you double or tripple them up so you can switch to another when the first one starts to die?  kinda like you can with the ua-5?

No need to triple them up.  Just wire two connectors in parallel on the end of your JB3 power plug.

When batt #1 starts getting low, plug in #2 on the 2nd input plug and remove #1.  When the #2 gets low, plug in a newly recharged RC on plug #1 and remove the #2.

[Brian Skalinder]

Here's David Klein's post from the NJB3Tapers group:

ondering if anyone else running external has ever run into this:

I've had a 4 pack of Nimh batteries that are so fully charged they won't
power up the JB3 because the voltage is just a little over the max (measures
~5.8v on my old analog meter). If I discharge the batteries a little bit
(run a halogen bulb for a minute or two) everything is good. This has only
happened when I've left the batteries on trickle for a while after charging
and they get completely topped up.

Also, a little while ago somebody had posted the *exact* operating voltage
tolerances for the JB3 but I can't seem to find it. It must have been done
with a good regulated power source - if you've got the numbers could you
post or email me offlist.

Thanks

david

I have a handful of 8000 mAH D-cell NiMH rechargables at home, so I may set up a sled for those instead of or in addition to trying the 9.6v RC batt / VR setup.  Decisions, decisions...

[Ed.]

if a 4.8v rc battery will work, can you double or tripple them up so you can switch to another when the first one starts to die?  kinda like you can with the ua-5?

No need to triple them up.  Just wire two connectors in parallel on the end of your JB3 power plug.

When batt #1 starts getting low, plug in #2 on the 2nd input plug and remove #1.  When the #2 gets low, plug in a newly recharged RC on plug #1 and remove the #2.

hehe, thats kinda what i meant, just couldn't think of the proper words to use.

[Phil]

Use the RC's then when they go bad buy a coupla 8 slot AA sleds, solder in some RC wire connectors and your set.  I use 2100mAh rechargable's and they get me about 4 hours.  For the festi you could just buy a 20 pack of disposables. And if you follow the jshapiro method you will have another open connector for hot-swapping, there you can hook up a volt meeter to keep an eye on things.  I've found that when it drops more than 9.8volts, get ready to switch batteries.  The sled costs $1.99 at Ratshack, shit buy 2.

[jasonw]

That sled fits into the back of the jb3???

[Phil]

Use the RC's then when they go bad buy a coupla 8 slot AA sleds, solder in some RC wire connectors and your set.  I use 2100mAh rechargable's and they get me about 4 hours.  For the festi you could just buy a 20 pack of disposables. And if you follow the jshapiro method you will have another open connector for hot-swapping, there you can hook up a volt meeter to keep an eye on things.  I've found that when it drops more than 9.8volts, get ready to switch batteries.  The sled costs $1.99 at Ratshack, shit buy 2.

ha... Nevermind.  had some cocktails last night, this is a battery solution for a UA-5 NOT JB3, please don't loaf your meat with my idea.  Sorry  

[John R]

isn't there a creative car adapter that could be hacked onto a 12v sla?  it would deliver perfect voltage?

jr

i was just over at their site.  no 12v adapter for the jb3, everything else though.

 

[phisherman2002]

You might want to try one of these:
http://store.yahoo.com/semsons-inc/powerbank.html

Basically it takes 4 NiMH batteries and powers damn near anything that runs off batteries through a selectable voltage lever. It will also recharge batteries. I just got one yesterday and dont know how long it will power the JB3 for yet.

[John R]

that looks promising.  keep us posted

[sickrick43]

isn't there a creative car adapter that could be hacked onto a 12v sla?  it would deliver perfect voltage?

jr

i was just over at their site.  no 12v adapter for the jb3, everything else though.

 

http://www.nomadworld.com/accessories/jb3-carkit/

There is a car adapter, (and the hinky cassette thingy).  Remember tho', you'll have to feed it 12V, the purpose of the adapter is to dissipate the excess voltage (which means it drops it accross resistors and a voltage regulator = heat/wasted energy).

From the looks of it, the actual circuitry is in the little box on the wire, instead of the lighter plug, which means your "should" be able to snip it off and wire it to the battery/adapter plug of your choice.  

But again, the step-down from 12v to 5v means over 1/2 the voltage you're feeding it is WASTED.  This would probably be extremely inefficient for RC batteries, but I'm considering trying one of these on my 6V/12V Eco-Charge EC-90, since I won't be running the D-10 anyway, only the V3 on the 6V end.  Probably get about 6hrs or so off it this way.

Rick

Ahhh.  Boner-ooo..  $1000 for VIP tix (the only way to fly), $1,000 for the 40' Winny-bagel (again, the only way to fly - roughing it for me, is Comfort Suites instead of the Marriot <BSEG>).  Mud, sweaty dirt-surfers, cigarette grubbers...  Think I'll wait for Dead Rocks @ Red Rocks...

[John R]

thanks rick.  weird how it's in accessories but not portable audio accessories.  yeah the power loss through heat is pretty large, but with an ec-90, and full access to power, i think i'll be good to go this summer.

jr

[Lee]

I'd love to see this on top of someone's stand at the 'roo

http://www.windupradio.com/icp/isun.htm

throw a little regulator on it and you'd be in business (until the clouds came )

[BC]

or if they charge fast, just get a simple power inverter for the car, and charge them every chance you get

If you do this make sure you run the car to charge the battery. I was charging saturday to do the MMW midnight show only to find the car (and damn power locks!) dead when I tried to open it at 11:30PM to go to the show. So instead of seeing MMW I got to go to the tow booth and wait around for the guy to come pop the car open.  
Not fun