Yeah, it is nice. The eagletree is probably more than I need. I would just like something that would log voltage drop and current to see if whatever battery I chose is up to the task. I would hate to find out by developing a puffed pack...

I just about had my mind made up on the 9920/8XL/UBEC combo to go with an Eagletree data system (dual temps, driveline rpm, motor rpm, etc.) then one of my friends here send's me a PM saying:

GO LEHNER!!!

Now I'm thinking hard about doing the 9920/1940-8/UBEC!

maybe I should just invest the money, then it's done! Reliable, fast, efficient!

The data package could follow right after I guess.

You could go with a 1950 7t procharge.

Why? help me out here.

I like the fact that is has a 5mm shaft, thats good. More strength & better pinion selection. It's a longer motor case & rotor so I assume it makes more torque.

Do I need it (or want it)? $335 is alot of green for a motor! Sell me!

btw, Mike seems to be out of most of the 1940's and 1950's. Bummer. Wonder when they'll come back in stock?

Have you seen the Eagle Tree MicroPower?
http://www2.towerhobbies.com/cgi-bin...&I=LXMBS3&P=ML
It's only $2 more than the DPR, and can handle 15 more volts. The MicroPower is great! Eagle Tree also makes more add-on sensors for it, even an optical RPM sensor!

Wow, I didn't realize it was that cheap! I could have sworn it was over $100...

Eagle Tree's other model is more expensive:
http://www2.towerhobbies.com/cgi-bin...?&I=LXGEK1&P=7
It can take more sensors and is more powerful in terms of what it can do.

Yeah, that's the one I was thinking of, but I thought it was more. Cool. :)

Lol, found a little error in their website while looking around. Go to this page and hover over the orange menu buttons at the top and watch the wording starting on the third button...

Wow, nice find!
I picked up the Eagletree micropower, powerpanel lcd, temp and brushless inline rpm sensor.
I don't use Deans so I got the version with wire leads.
This little guy was worth the $$$ IMO

how could one determine what batteries are needed to feed a specific motor?
with that i mean; how does one know how many amps a setup will pull?
before you have it up and running?

Jolly, I'm curious about the same question. It really comes down to Watts and how much of it your car needs. Looks like a 1:8 buggy will see peaks of 2000 Watts, so 70A peaks @ 30V.

Can anyone point us to graphs of some electric setups? So far I've only found this one.

what i also wanna know is this:
lets say battery has these specs: 100A continu, 150A peak and 200A burst
but the motor wants for example 150A continu and to start he wants 250A.
what happens then to the battery?
this is about lipo or li-mn?!?

If the battery can't supply the current the motor wants, then the battery will drop its voltage, which in turn lowers the current draw. This is why you want a battery that is able to handle the motor you choose.

Well, I would hook up a set of good NiMHs of the voltage I was looking at running just to get a baseline reading. Install the eagletree, and run it like you would at worst-case conditions (lots of stops and starts and heavy acceleration). After a few minutes, you should have enough data on the logger to see what your currents are. I'd probably look for a lipo whose continuous C rating is equal or more than the peak rating on the logger. A little overkill maybe, but the voltage drop will be more stable and the packs will run cooler.