How much battery do I need?

[zeropointbug]

I am running 1p pack right now, I switched back from my other 7s2p pack, I kinda like it, not as punchy, but the Revo feels more agile.

Oh, and I made a mistake, my Revo is just under 10 pounds actually, not a little over 9lbs.

Well, the higher the voltage of your pack, the higher the potential amp draw, but it depends, it can draw some amps in the right conditions when voltage drops a lot. My pack usually drops to 19volts from 23v nom., but also, I am finding that the nom. voltage is something more like 3.1 - 3.2v/cell for A123... still experimenting!

[zeropointbug]

Your 8T will probably draw about 80 amps consistant peaks, sometimes hitting maybe 90 amps if you really hit on it hard. You should just get an eagletree now, they are cheap... lol, you have spent a lot of money on this R/C stuff, surely you can afford an eagletree! Caugh! $90 Caugh!

[offroader]

What is the advantages of running a higher voltage 5S pack 18.5V as to a lower voltage 3S pack 11.1V? Will the higher voltage run lets say a 8xl motor faster? Will this motor run hotter at higher or lower voltage? Will your run time be longer on a higher voltage?
Anyone? I'm new at this just figured I'll ask the questions since there's so many options.

Speaking in terms of systems, higher voltage systems will draw less current than a lower voltage system. That is to say that a system based on 5S lipo turning 30,000rpms will draw less current than a 3S system turning 30,000rpms (all other things being equal). The higher voltage system will run much cooler.

I consider the 8XL and 9XL to be 4S motors. If you want to run 5S, I'd go to a 10XL.

[offroader]

AAngel, if you go with lets say a higher voltage will you still get the speed out of the higher turn motor or will the lower voltage with the smaller turn motors have more power? Can any BL motor take the lower or higher voltages 2S-6S?

Originally Posted by AAngel

Speaking in terms of systems, higher voltage systems will draw less current than a lower voltage system. That is to say that a system based on 5S lipo turning 30,000rpms will draw less current than a 3S system turning 30,000rpms (all other things being equal). The higher voltage system will run much cooler.

I consider the 8XL and 9XL to be 4S motors. If you want to run 5S, I'd go to a 10XL.

offroader,

If you think of power in terms of watts, then yes, a 3S system will be as powerful as a 4S system, if both systems are setup to do the same amount of work.

Not all brushless motors can handle the same voltage. Motors have limitations in terms of how many rpms they can turn before tearing themselves apart.

Although some advocate running motors to higher rpms, I like to keep my setups at around 30,000 rpms. This makes for cool running no matter the ambient temperature or terrain. I run Neu motors, which are arguably the best motors available right now. A 2200kv motor on 4S or 1700kv motor on 5S is a pretty solid setup.

In answering your question, the two systems that I referred to will run about the same in terms of speed, but the 5S system will run cooler, because it will draw less current.

[BP-Revo]

I actually have some 30C FlightPowers which I am dying to test out. I just need an ESC for my G2R! They are the 4500mah versions. Thats right, 135 amps continuous if they prove true to their rating, which I believe they will. The point of getting these is that, if I recall correctly, at lower drains such as 15C or so, voltage stayed as high as 3.6V per cell, which is quite phenomenal.

If I were to suggest batteries, I would suggest FlightPower Packs, the 25C or the 30C - they should be more than enough battery for anything short of a 1:1 car...

[offroader]

When using a 3S 11.1V or 5S 18.5V will a 8XL (2084kv) max 83A motor run hotter or a 12L (2050kv) max 51A as you see both of these motors have close to the same kv. Which motor will be more efficient in terms of longer run time and running cooler?

I think that the L can motor will run hotter. It's going to have to work too hard. The XL can will have more torque and will handle gearing better. The 8XL, as far as I'm concerned, is a 4S motor. Running it on 5S will get you heat problems. If you want to run 5S, I'd go to a 10XL.

[mwry13]

i just picked up some Neu 30c 5000 Mah Batteries from a buddy of mine and let me tell you... they fricking rock! and in my experiance max amps has some of the worst defect rates of any battery :( (well at least since i started working for a hobby store). granted im only running 4s in my kyosho but there soooo good :)