rusty land speed record

[klown]

20-30c is what it says on the shrink wrap.

 

[flm_savage]

So 20c constant. 32amps. This is something you would run on an 18th scale. This is NOT the battery you want to attempt a high spoeed run with.

 

[klown]

i got it from the for sale post that rcnut143 had up here, https://www.rcnitrotalk.com/forum/showthread.php?t=80020... for what i got the lipo and the turnigy accucell 6 charger for it will work for the time being. once i am comfortable with the charge/discharge and balance of the lipo and the new charger then i will get a much larger lipo to better suit my needs. i just didnt wanna spend the new lipo price to destroy a battery.

 

[flm_savage]

Your call. I expect the battery to fail shortly.

Just so you know the velineon motor is rated for 65a when on 3s and that's probably rms. Speed runs will put even more of a load on it.

 

[alpinehyperlite]

Yea remember that whole "up in flames" post about the motor? Thats whats going to happen to this lipo. Quite quickly i assume. Good luck..

 

[klown]

ok, thanks for all the info about the lipo battery. i do have a question concerning lipo ratings in relation with the size of the rig you are running.

how is it that two batteries (lipo) can have the exact same ratings as far as cell count, mah and c ratings and be for diffrent scales? i am a complete noob about the lipo's, but it would seem to me that as long as the cell count and discharge ratings were correct the battery would work just fine. especially since the vxl esc has lipo mode( and is currently in lipo mode) and will shut off when it reaches the lvc. i do appreciate everything that has been pointed out to me here. I'm sure without the help i have recieved as of now my rusty would be just a pile of smoldering trash that looked cool for about 2.3 seconds. lol.

please point me in the correct direction to achieve what i am looking for in a lipo, and hopefully at a decent price. hard to justify a battery that costs more than what i have invested in the whole truck, even to myself let alone the wife. lol.

thanks again for all the help and insight. nick

 

[flm_savage]

you size the battery according to the motor you are running.

look at the motor wattage and use that to give you a ballpark on current draw. You always want some overhead as well. 5000mah packs are very popular because even with a low C rating (20) you can still pull 100A (enough for most 1/10th setups) and they physically aren't that large.

i may tear my tranny down and take out the locked diff so both back wheels wont dig, that may help with the tremondous low end torque.

so to combat excess torque, you are going to reduce traction?

 

[klown]

so to combat excess torque, you are going to reduce traction?

i was thinking that with only one wheel grabbing on the initial throttle response would more than likely send into a fishtale of sorts as opposed to sticking the nose straight in the air. atleast that works in my mind... lol but its hard to say what else works in my mind that has no practicle purpose, let alone actually work the way i envisioned them. lol.

you size the battery according to the motor you are running. look at the motor wattage and use that to give you a ballpark on current draw. You always want some overhead as well. 5000mah packs are very popular because even with a low C rating (20) you can still pull 100A (enough for most 1/10th setups) and they physically aren't that large.

i am a little confused about this math... i have read every sticky and forum post from here to shangra-la and cannot wrap my head around all the numbers and formulas and it make any cents to me. the velineon system has a 3500 10 turn brushless motor and has a 65amp constant with a 100 amp peak/burst. the vxl3s esc is showing a continuous current of 200 amps and a 320 amp peak.... so with a 5000mah 3s battery with a discharge rating of 20c/30c would power it sufficently or over power the motor? for example a battery like this one,http://hobbycity.com/hobbycity/stor...roduct_Name=Turnigy_5000mAh_3S_20C_Lipo_Pack)... and how does the 3s2p play into this, for example http://www.maxamps.com/Lipo-6500-111-Pack.htm, not that i could afford that, but almost 40 minutes of runtime thats gotta be cool.

 

[flm_savage]

so you need a battery that can supply a minimum of 100A constant. I always prefer to keep my peak current use within the constant range of the battery.

5000mah with a minimum C of 20
4000 with a minimum C of 25
3000 with a minimum C of 35

 

[darkslayor24]

i have never put so much thought into a battery. of course when i made the switch over to brushless i just plugged in my 3200mah 2s 25c and ran. i have no idea what my motors draw rating is or anything. i just know what size pack and what C rating i need lol

 

[flm_savage]

i just know what size pack and what C rating i need

and you determine this by...........

 

[klown]

so you need a battery that can supply a minimum of 100A constant. I always prefer to keep my peak current use within the constant range of the battery.

5000mah with a minimum C of 20
4000 with a minimum C of 25
3000 with a minimum C of 35

if i were to get a 5000mah with a 35c rating would that over power my setup? i understand that the higher the c rating the more "punch" you have on initial take off and more power thru out the rev of the motor. i just wanna make sure that the battery i get is not gonna smoke my esc when i hook it up and let it loose.

 

[flm_savage]

no, your battery only delivers the current that is "requested" from it by the esc. You just want to make sure that the battery is always sized so that it can always fulfill that request and ideally have more to give if it was ever needed.

 

[darkslayor24]

and you determine this by...........

i was told flat out by my fellow racers what i needed. lol