maddmatt02

alright, I was looking at ST's but I am fairly set on buying myself a brushless MT after xmas, waiting because there is a chance I am getting an R/C model for xmas.

anyways, I am going to get the kyosho madforce kruiser VE. it was between that and buying a MGT 4.60 and selling the nitro stuff and converting. I would probably only have 260 or so into the MGt after selling the tank/pipe/engine, but I dont think that for 150 I could convert the MGT. I have had the MGT 4.60 before and it was really durable and I liked it alot, but I kinda want to try something different. i went to the LHS and they have a whole wall full of traxxas stuff, a few losi bags on the wall and nothing else, so AE or kyosho they would have to order the parts. I like the E MAXX as well, but its more than the kyosho and is still brushed...

now that I have rambled on and on off topic, i will get back to it, I cannot find any info on the current draw of the team orion vortex 8 system, not even on team orions website.

I found some turnigy hard case 2s 5200mah lipos that are about the same size as 6 cell nimhs, so they would fit. they are a good price. but there is the 20c/30c burst, or the 30c/40c burst.

I know if you parallel the packs the current demand is halved on each pack, but I wouldnt want to lose all that performance from 4s(series)

so a 5200mah x 20c = 104 amps continuous/ 5200 x 30= 156 burst, 30c/40c pack could supply 156/208 burst.

is the 20c enough?

I was also thinking about modding the battery trays to parallel a couple of 3s packs to lose a bit of performance and lengthen run times. I could still get high capacity 30c packs, but the voltage is lower. and I know the actual power (wattage) depends on amperage AND voltage, so will the motor place a higher amperage draw on a lower voltage pack? or no?

and lastly, I was wondering about 2 high capacity 2s in parallel vs 2 lower capacity 2s in series. say I had 2 5000mah 2s packs in parallel, so I have basically a 2s 10,000mah battery, and then I had 2 2500mah 2s packs in series, so basically a 4s 2500mah. if both packs are 20C, the 2s would deliver 4x the amperage as the 4s, right? BUT at 1/4 the voltage. so either pack has the ability to theoretically supply the motor with the same wattage, am I still right?

but if the battery cant deliver the current the motor wants, is the battery going to be damaged, or will there just be less performance than if I had a battery capable of supplying more current?

guver

My Feedback: (325)

I don't know actual current of your system and have no idea if specific pack is enough. Possibly someone knows specific current , but you'd have to tell them your weight and speed and terrain first (basically the total load) Then there's going to be trouble deciding if we trust the ratings to be actual or not.

For two identical syslems the one with lower voltage will pull much lower current. so the motor will place a lower amperage draw on a lower voltage pack.

2S x 10000 (pair of 5000 mah packs)
4S x 2500 is half the batery as the pair of 5000 packs and can be half the wattage. I think you misfigured , it is 1/2 the voltage , not 1/4 the voltage.

When a pack cannot keep up with the current demand the pack generally overheats and can be damaged , not always.

maddmatt02

yeah, I had it as 4s 5000mah at first, and did have it written as 1/2 the voltage. when I read through it myself, I noticed the first mistake about the 4s 5000mah and fixed it to 4s 2500mah, and then I guess since 10000 is 4x 2500mah, I confused the capacity and voltage or something, not sure exactly WHAT I was thinking, but i changed the "1/2" part to "1/4"...



so a higher voltage pack makes the esc/motor pull a higher amperage, kinda makes sense to me, but it would just seem that even with the higher voltage, an identical amperage would give the motor alot more power, so more voltage and more amperage would be alot more power. so is the difference between the number of cells an exponential power increase and not just "double the cells, double the power"

guver

My Feedback: (325)

Yea, ok so they are equal then. 2s x10,000 vs. 4s x 5000 mah. You are correct it gives it a lot more power than double. I'm not sure it is exponential , but it is much more than double the voltage doubles the power. It may be "squared"? I'm not sure how to say it. It souinds like You sure do have these concepts down pat.

Here's another interesting comparison (instead of keeping the systems identical)

2s system going 50 mph vs. 4s system going 50 mph (by using a lower kv motor or lower gears) The high voltage system is usually going to be more efficient. One of my favorite set-ups is a 6S set-up in 1/10 scale ST using a standard sized low KV motor allows me to get away with tiny 1/18 scale packs. Many told me a 1700 mah 10C pack would never hold up in a 1/10 scale truck , but it does because the current goes way down when we keep the speed the same.

maddmatt02

??? I thought we were both right the first time, a pair of 2s 2500mah batteries would essentially be a 4s 2500mah pack....

I might just be trying to sound smarter than I really am... [&:]

I did start reading up to become MECP certified but never finished studying and never took the test. it also has nothing to do with R/C but it was alot about resistance and current, etc... and all the formulas. but i have forgotten probably 99% of the stuff I learned.

nitro newby

well it looks as if im late, but i heard that the orion was a hobbywing Xerun (dont take this as for sure, just what i think i read on a different forum, and dont mean anything against any company's) so you might could try to find the specs on one of those

maddmatt02

well, I cheaped out and got an evader off CL, and got a HW EZRUN 60A/Tacon setup. and Im running 5kmah 20c 2S batteries with no problems.