[kirtar]

I've been looking around for stuff to make a (modified tangent) CMoy amp, and I pretty much have my shopping list made, coming out to ~$35/amp right now, but I can't really decide on what batteries to use. The popular choice is to use 9v batteries, sometimes in series. Thing is, I tend to like to use rechargeable batteries, for no particularly good reason.

Reason why I can't decide:
1 9v rechargeable runs around $10 ($5 from DX)
2 3.6v lithium rechargeables run about $5 (DealExtreme) and have higher capacity. Cheap charger as well.

So would it be better to hook up 4-6 16340/CR2 cells in series or to have 1-2 9 volts in series? The lithiums would last longer, but then I'd have to make a holder for them to allow easy replacement, unless there are some out there that I haven't seen. Also, the lithiums will take a bit more space, but will the additional space used be an issue? I currently have the case tangent listed on my shopping list, but I could theoretically make my own, using wood, polycarbonate/lexan, and/or sheet metal (Al?).
(Protected vs unprotected, if using the lithium cells? Can get unprotected for like half the price)

 

[vixr]

the 9v rechargables I have in my CMoy (see sig) take like 14 hours to recharge...the 10 cell AA pack I built for my pimeta (see sig) takes like 2.5 hours to recharge!!! While cost wasn't an issue for me, the time sitting on the charger was. I hate waiting for my gear to charge.

 

[kirtar]

In this case, cost isn't really (big) issue (anymore...). Instead charging time, run time, and (to a lesser extent) space are more of the issue, space being why I'm leaning to lithium rechargeables rather than NiMHs, etc. If it was feasible, I'd just stick 4 18650 cells in, but I'm not sure how much space I'd get to work with in the case I'm ordering (The serpac one...). If the 18650s won't fit in the serpac case, is there another pocket-sized case that could fit a cmoy with 3 or 4 18650 cells (Figure about 66.3 with 18.12mm diameter)?
How hard would it be to make a holder for more uncommon (ie not AA, AAA, D, etc) batteries (Found some about the same size as AA as well, but other cells are cheaper) ?

Also, for reference on choosing a different case, how much space should I leave for the circuit board (I'm going to be using the TLE rail divider circuit from Tangent. Should be the only significant difference beside replacing a couple components with similar ones)? [Currently looking at the patecenclosure HML using 3 18650 cells or 3/4 cr123s, since I can't find anything that is wide enough for 4 without having oodles too much extra space...Looking for ID ~4"x~2.5"x~1"]

 

[kirtar]

*Bump*

I figure I better post my parts list just in case I'm missing something or have something I could easily improve on. All part numbers are from digikey

1 x 470 uF electrolytic capacitor (P12389-ND)
10k, 4.7k, 100k, 1k resistors as listed on tangentsoft (not going to put codes)
2 x 3.4k resistor (3.40KXBK-ND)
2 x .39uF capacitor (PF2394-ND)
1 x Op amp (OPA2132PA)
1 x LED (160-1708)
2 x Stereo Jack (CP1-3513SJCT-ND)
2 x DIP Sockets (ED3308-ND)
1 x Sliding switch (SW148-ND)
1 x Thumbwheel potentiometer (P4E3103-ND)
1 x Pactec HML enclosure
1 x TLE2426CP (296-6548-5-ND)
(Maybe 2 caps for after the rail splitter?)
4 x Trustfire (550 mAh) 3.6v protected cr123a lithium batteries + charger
(or 3 2000mAh 3.6v 18650 protected cells)

Is there anything else that I might need/What would I need to make a holder for the batteries?