Nexus Racing has them in stock
4000mah 25C 3.7V Lipo Single-Cell Battery for 1/12 (w/ hard case)
Part#: SMC 4025S
In Stock
$54.95
http://www.nexusracing.com/product_info.php?products_id=2395 (http://www.nexusracing.com/product_info.php?products_id=2395)
-=light=-
Yeah, some of the folks on RC Tech have been yakking about these. Supposedly a single cell Lipo, with a 13.5 brushless is just as fast as a 27T 4Cell stock. You will also need to add a RX'er pack to the car was well, since the electronics dont like the lower voltages.
Could be the future though.
Shawn.
where u gunna fit a reciever pack??..lol
Hey, Guys.
One of our customers trialled the LiPo in Calgary for 1/12 and here is what he had to say:
Well, last night was the first night for my single cell lipo. I'd have to say it was a success. I will have to do the math on rollout...but ended up geared at 38/74. Started the night at 40/74, but she lacked a bit of punch. Even at 38/74 it was a bit soft...but the speeds were there. No lap counter therelast night, but I didn't really have a problem running with the 13.5 /4cell guys. Mind you...our track is small. I am really gonna love all this battery maintenance now ! HAHAHA.
Electronics were as follows...your 13.5 (of course), the new KO VFS-1 BMC speedo, KO 2.4 receiver ,and a KO 949 servo(I think?).
I was not using a reciever pack...powered it all from the SMC 4000 1s cell. Motor temps about 110 degrees. Speedo 102 degrees.
Pretty excited by the outcome.
It will be interesting to hear what ROAR comes up with and what will happen for retro-fitting saddle pack cars (cell can interfere with the shock etc, not to mention the T-Bars). Interesting that he didn't need to run a receiver pack.
P.
2 cells with a higher turn brushless makes more sense to me. That way you don't need to run seperate power for your receiver/servo. Two batteries is a big deal when you forget to recharge your reciever pack. Need to keep it as simple as possible.....
Quote from: Grinder on January 12, 2009, 11:21:41 PM
2 cells with a higher turn brushless makes more sense to me. That way you don't need to run seperate power for your receiver/servo. Two batteries is a big deal when you forget to recharge your reciever pack. Need to keep it as simple as possible.....
I heard with a 21.5 if you mount the spur on the motor, and put the pinion on the axle, the speeds are close to a 27 turn. :-)
Joking aside, the A123 cells look pretty good, and 3.7 voltage Lipo really shouldnt be an issue for most electronics these days. But lets face it, I am running last years GrePows without a problem, and I have not heard of anyone having a problem with the new NiMH.
I dont understand why everone wants to run to a new tech, when the old stuff is currently working fine.
Shawn.
I bought one of the cells on my last order , Yesterday I played around a bit to see if things would work out.
Things I found out
1: Battery peaks at 4.2 volts
2: Lipo weights in at 120 grams
3: Receivers I tried two different spektrum units. They Do not work under 4 volts
4: You will need a receiver pack or a voltage booster to use this
Today I ordered 3 of these to solve the problem of low voltage
(http://www.hobbycity.com/hobbycity/store/catalog/Voltagebooster.jpg)
So what exactly are "these"? Some sort of boost regulator. What is the current rating on these? Remember you need to drive your servo as well as your reciever....
Quote from: light on January 19, 2009, 02:30:43 PM
I bought one of the cells on my last order , Yesterday I played around a bit to see if things would work out.
Things I found out
1: Battery peaks at 4.2 volts
2: Lipo weights in at 120 grams
3: Receivers I tried two different spektrum units. They Do not work under 4 volts
4: You will need a receiver pack or a voltage booster to use this
Today I ordered 3 of these to solve the problem of low voltage
(http://www.hobbycity.com/hobbycity/store/catalog/Voltagebooster.jpg)
Lipoly Single cell voltage booster for Receivers
This little unit plugs into your single cell lipoly and will boost the voltage to 5V, allowing you to run a receiver on a single cell lipo!
Why would you want to do this? Less weight of course!
Operating Voltage : 2.7V - 4.2V
Operating Current : 1A
Max operating Current : 1.5A
DC to DC converter.
Here's a link to the datasheet. You can get these upto 15Amps or so.
http://media.digikey.com/pdf/Data%20Sheets/Bel%20Fuse%20PDFs/x7AH-02C.pdf
Shawn/
Wow those are super expensive - no inductor needed though - all in one package...