Internal Rechargeable Batteries?

[jishnudg]

Been thinking about this for a while, thought I'd put it out there  --  how about if pedals could be used like cellphones are? With rechargeable batteries (hopefully with longer battery life - - say 100 hours or something? )....wouldn't that be so much more convenient for folks who don't want to use wall warts?

Google search threw up this New Zealand based company that's doing something of the sort -

http://www.redwitchpedals.com/index.php?option=com_content&view=article&id=52&Itemid=69

So what would be a good way to go about thinking of DIYing something similar?

[pappasmurfsharem]

Been thinking about this for a while, thought I'd put it out there  --  how about if pedals could be used like cellphones are? With rechargeable batteries (hopefully with longer battery life - - say 100 hours or something? )....wouldn't that be so much more convenient for folks who don't want to use wall warts?

Google search threw up this New Zealand based company that's doing something of the sort -

http://www.redwitchpedals.com/index.php?option=com_content&view=article&id=52&Itemid=69

So what would be a good way to go about thinking of DIYing something similar?

It's been discussed before using something like lithiums downside is size generally. The problem with. Cell phone sized lithiums are that they are only generally a handful of volts at full charge and generally can be dangerous when pushed over the edge. Not impossible but then you also have to deal with recharge cycles since batteries have a recharge lifespan. And either stop working or become  dangerous when used passed those limits

[Jdansti]

See this:

http://www.diystompboxes.com/smfforum/index.php?topic=105414.0

[amptramp]

and follow the link to here:

http://www.diystompboxes.com/smfforum/index.php?topic=105617.60

In fact, the whole thread is good reading.

[jishnudg]

I was actually thinking of putting a laptop battery inside a (larger than usual) stompbox....how safe/unsafe is that...how often will I have to charge it (with a laptop adapter, of course)? I don't mind a lifespan of a few days (!) even if the size of the box doubles, in this case...just to try out the concept of it.

[jishnudg]

Of course, I'll obviously need some regulating supporting circuitry - - perhaps a lot of it to ensure safe charging and safe operation of the battery...

[R.G.]

As a retro-alternative, you can get lead-acid gel-cells that are sealed and can be mounted in any position. They make a version with 12V in about 1.5x3x5 inch box. More capacity is available from two 6V's in the same size package. This gives you 12V, which can be regulated to 9Vdc with a three-terminal regulator.

Or you can hacksaw apart a drill-driver to use the handle for a socket for the rechargeable battery packs for the drill driver.

Both of these are easier and less dangerous than mucking with lithium batteries. They are a real fire and burn hazard if mistreated.

[PRR]

> rechargeable battery packs for the drill driver.
> less dangerous than mucking with lithium batteries.

FWIW, FYI..... the somewhat tame NiCad is going out of style in cordless drills (and almost everything else).

I have a good investment in NiCad cordless tools. Every Father's Day I scour the ads for bits I need. The NiCad stuff has vanished. Ryobi wants me to discard my old system and buy into their new Lithium system. I can see that as first-adopter prices fall, I will have to.

True, for the much smaller demand of pedals (nothing like cutting roots with the cordless saw), the several year old half-dead NiCads will probably give acceptable service. And the way marketing works, they will probably be turning up at a GoodWill near you soon.

[R.G.]

Note that I didn't say to avoid the lithium battery drill-drivers, only advised against mucking with lithium batteries raw. That may not have been clear.

If you use their integrated battery packs and the charger, you get the electronics that watch the lithium charge cycle to feed and care for them with (hopefully) no tears and no fires. 

NiCads have that ugly memory issue and are h e a v y for the amount of energy stored - but they do have a much higher peak current rating, at least compared to the early lithium batteries.

And you are right - half dead nicads would work fine for the needs of pedals.

I keep coming back to lead-acid. The technology has had over a century of technical work, and is pretty well known as well as not being picky and demanding.

[PRR]

> back to lead-acid.

Agree. But the minimum size which is readily available is a 2V D-cell, or rather the 6V and 12V hunks sold for alarm backup.

12V 7AH is a *very* common size and generic everywhere. However HomeDespot also lists a smaller 4.5AH lump.

Chamberlain # 4228 Replacement Garage Door Opener Battery
4.5AH
$21.43
Depth (in.)     3.0 in
Height (in.)     2.5 in
Width (in.)     2.5 in
Weight (lb.)     4 lb

Mighty Mule  # FM150-EFK
12-Volt Replacement Battery and Fuse Combo Kit for Mighty Mule Gate Openers
$20.97
12-Volt, 7 amp/hour replacement battery
Depth (in.)     4.25 in
Height (in.)     3 in
Width (in.)     7 in     
Weight (lb.)     2 lb 

UPG # 40800
Sealed 12-Volt 7 Ah Capacity F1 Terminal AGM Battery
$31.49
Depth (in.)     5.94 in
Height (in.)     3.94 in
Width (in.)     2.56 in
Weight (lb.)     4.5 lb

I do not know why the $32 and $21 models have the same AH rating but very different weights. However it is clear the HomeDepot site is confused, because the $32 job is listed "Rechargeable     No". 

Assuming six FuzzFaces, 1mA for guts and 9mA for LED, 60mA total, the 7AH lumps will run over 100 hours, which is more than you can play at one stretch. However a dozen hungrier pedals may run closer to 7 hours, and you should not push this too close for good battery health and to leave a margin as the battery silts-up with age. If you do a 4pm setup, break for dinner, and want to play past midnight, you may need to remember power-down at dinner or even throw a charger on it after the third set.

[aron]

I used to use batteries - rechargeable or otherwise. However once I used the One Spot(s), I never looked back. If my amp cannot get power, then my pedal board doesn't really matter :-)
Yes, if you use batteries run a regulator. I really got tired of my pedal board sounding different over time due to fluctuating voltages.

[R.G.]

Here's an example of what I was talking about:
http://www.batterywholesale.com/battery-store/proddetail.html?prodID=368
It's 1.7" by 2" by 3.8" long, weighs two pounds, and costs $10.38.

If you're willing to spend a bit over $12, you can get a pair of these:
http://www.batterywholesale.com/battery-store/proddetail.html?prodID=158
They are half the thickness, so a pair of them fits a flatter - but wider - space.

There exist 4V sealed lead-acid batteries, which might get to 9-10V naturally.

[petey twofinger]

i found a ryobi lion 18v w/ charger for 5.99 at goodwill  , that battery is amazing , and its light ... i love it . not a huge fan of the 18v nicads though .

we use 12v 7mah cells for pedals and amps outdoors often . i have 14 atm , but i got em for cheap. they work very very well , especially with a proper smart /  float charger . look for belkin ups at resale as uverse used these and they were goin around strong for a few years but seem to be drying up lately .

the tesla electric car has 7000 3.6 volt lion cells in its frame ... that thing is pretty rad too . well it puts the zap zebra to shame anyway . personnaly i cant wait for battery technology to advance but i am really doubtful , it seems like big oil wouldnt want that to happen .

electronics goldmine had a sale on nihm 4.8 packs , they were 99 cents and about the size of three triple a cells .

lion is tops i think , nihm is better than nicad , i run my fernandes sustainer off a 9.6 remote control car pack for years now . it sits in the strap , and i paid 2 bucks for it at resale . they have gell cells too , if you like to spend loads of $$$$ ...

[PRR]

Thanks for finding the 1.3AH units.

> i cant wait for battery technology to advance

On the whole, advancement has been slow. Modern lead car batteries are better in small ways than batteries of a century ago. NiCad is better than lead for some things, worse in others. The NiMh and LiOn chemistries did come out "suddenly" in the last couple decades. Note that they have been plagued by problems. Over-heating and fire probably just come with super-active chemistries and excessive (sloppy) production.

> it seems like big oil wouldnt want that to happen.

"Big Oil" doesn't give a rat's behind.

Extracting and refining oil is actually somewhat expensive; selling it is VERY competitive. If demand went down (and it won't, not a lot not soon), they'd just pump/boil less of it and still get a good profit skim. They'd rather not reduce their present operations, but they are conservative about expanding operations. (What's the worst could happen? Demand rises suddenly, supply lags, price goes through the roof, profits rise!)

And for the short-term, much of the generating capacity to re-fill any electric cars is going to come from oil-fired turbines. (All the hydro is used, there's no new Nukes, and new coal is discouraged.) (Wind? Solar? For an iPod, not an entire energy-crazed society.)

Also the broader oil companies have their fingers in many pies, including electrics.

Disclosure: I own a couple shares of what used to be Esso. I don't remember why. I won't buy Exxon if I see another brand. But I do get some insight into what they do from a lovely glossy peppy magazine they sent to shareholders.

[petey twofinger]

we  run all of our amps on 12 volt 7 mah batterys , a full day and night of playing runs over 8 hours . with class d amp boards , rated 25  x 2 , going out with the cell at 13.5 typically we return at 12.8 to 12.5 . thats four speakers per amp , mine has two tens two 8's and horns .

the pedal boards , well those cells i use older battery's that charge up to like 13 ish .... last weekend = 12.98 , we returned , after running an rp8o , eq , rat , boss ns2 , plexi 800 at 12.81 . thats thru a 7809 .

the bass amp board is rated at 50x 2 runs two 12 volt 7 mah ,  those went out at 13 , returned at 12.65 .

13.06 with a nux time force , ce2  , morley wah , cot50 , dod250 , ea tremolo , and some floater pedals , that cell returned at 12.31 .

i use masking tape and a sharpie to keep track of most of the cells , and the amps have built in volt meters .

one thing i am not thrilled about is the fact that initially i had build 7809's into all the amps , and we really stopped using those because of heterodyning issues , and then just straining the batterys so i really should get in there and disconnect those or put them on switches , which , now that i think some are but ... i am pretty sure even if those are just sitting there they are using a little bit .

this year i built a 14 volt lion pack with a 7809 , and a smaller nicad pack like that too ( 1.2 volt c size cells that came out to around 13v ) . they are a lot smaller units . we did try both and i didnt get much run time out of either . one was powering a 200 mah draw multi fx , the other i think a drum machine , i am not sure but ... it could have been a few different issues , i need more time for testing and monkeying , but i honestly think i wouldnt want to go smaller than a 7mah , for our needs . ok , back to the lounge . srry.

[earthtonesaudio]

If batteries are too big and bulky, you could always go with a little gas turbine:
http://users.ntua.gr/rogdemma/MILLIMETER-SCALE,%20MEMS%20GAS%20TURBINE%20ENGINES.pdf

[PRR]

"...no one has yet reported an operating gas turbine engine at this scale.
"The challenge appears to be one mainly of stringent process control in a long, complex fabrication sequence, ....in many ways as challenging as that for a microprocessor."

[amptramp]

I believe a microscopic Wankel engine has been demonstrated.

http://www.me.berkeley.edu/ME219.SP04/Lectures/L39ME219.pdf

All you need is a microscopic RX-7.  How many gnatpower is your pedal going to require?

[PRR]

> a microscopic Wankel engine has been demonstrated.

Bunch of reports ~~2001, then nothing. Did EverReady buy-out the research to protect their bunny-battery business? Or is it just real difficult to get over-unity in a tiny heat-engine?

I'm all in favor of an alcohol-burning inch-long V-8 inside my laptop. But small engines have large problems.

[R.G.]

Microscopic Wankels and gas turbines are all fun, but I want one of LLNL's 20kW Stirling engines and the six-meter solar mirror that runs it.

I have several acres of open pasture down on the south slope that practically cries for a solar powered something to be there. 20KW is all I need to run the entire house, AC and all, during long, hot sunny Texas days. If you want to talk revolutionary, make a 20KW Stirling plant that will fit on a residential lawn that has a 20 year working life and can be paid for in 10 year note.  Things change rapidly then.