Battery Choices

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Old 03-09-2012, 04:14 AM
  #31  
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Originally Posted by 8ight-e View Post
He is correct, but also note higher 'c' rated packs in a given line will basically always have longer run times when comparing the same mAH; it will hold the voltage longer (straighter curve). So even if you have no gains in punch/power at peak because the motor has all it needs as the packs mAH gets lower the higher 'c' packs will hold that punch longer and net longer run times as well. Said packs will also run at a safer temp at low mAH, and last longer in most cases (more cycles). Note I said in a given product line.. 'c' rating from seller to seller is nearly useless to compare packs directly. The 90c Orion packs are way better than the 150c maxamps packs and they cost less. I'd actually put a nano-tech upper c rated pack in the same class as the 5x more expensive maxamps pack of equal mAH.. granted the MA packs are typically hard shell and a better size for racing. Obviously there are other choices that meet the size and hardshell requirements as well.

Lets just say you have a 5200mAH 20c and compare it to a 5000mAH 50c, in most cases you will have slightly longer run times (before LVC) with the 5k 50c even though the other pack has more mAH unless you are running a very very low demand setup where the system never pulls high amps.

5200 x 20c = 104amps
5000 x 50c = 250amps
5000 x 90c = 450amps

Granted these are not real continous amp draw figures, at that amp draw rate the packs would be empty in no time ;P

This is a huge deal in 4x4 racing and 1/8 racing.

I cannot speak highly enough of the Orion 90c 6500mAH packs worth every penny and then some.
Not always true, usually the opposite. The higher voltage under load typically drives more amp draw, thus draining the battery a little faster. Thatís been the experience of many that use wattmeters to measure the performance.

Generally a very small effect on cars, likely not very noticeable, as the loads/throttle settings vary a lot, not that much time at high amp loads. But can be quite noticeable in airplanes where a relatively high throttle load is frequently used for more of the run.
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Old 03-09-2012, 04:45 AM
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Originally Posted by Dave H View Post
Not always true, usually the opposite. The higher voltage under load typically drives more amp draw, thus draining the battery a little faster. That’s been the experience of many that use wattmeters to measure the performance.

Generally a very small effect on cars, likely not very noticeable, as the loads/throttle settings vary a lot, not that much time at high amp loads. But can be quite noticeable in airplanes where a relatively high throttle load is frequently used for more of the run.
The higher the voltage is the less the amp draw is.. to do the same job. The only way amp draw would remain the same or increase at a given voltage is if you were pushing for more. As a lipo runs out of mAH voltage drops in any application LOL (cars, planes, even trains ;P) and with ALL batteries.

Lets say the motor needs 1000watts to hit the top speed you want (geared for) down the straight this gearing now limits the system and it won't be asking for additional wattage unless you add a hill or change a variable

Voltage x Amps = Watts

7.4v x 135amps = 1000watts
6.2v x 161amps = 1000watts

As the pack looses voltage amp draw increases to make the same wattage, thus the longer the pack can hold voltage the amp draw remains lower creating less heat and increasing your run times. Temp is also what kills lipo's (makes the soft or poof), if you don't ever push the lipo past it's limit you will get more cycles.

This is not an opinion it is a fact.

Last edited by 8ight-e; 03-09-2012 at 04:58 AM.
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Old 03-09-2012, 09:07 AM
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Originally Posted by DirtRacer68 View Post
If I use the Wolf Pack with the Orion motor will there be a drop off in motor performance? Maybe Cavalieri could answer that question.
You might lose a little punch but that is the idea. Plus weight is a big factor. A driver might choose a shorty pack or the Wolfpack to either reduce the vehicle weight or make greater changes to weight distribution possible.

Ryan Maifield almost always use the WolfPack.

It is not always about power. Look at 4x4 SC racing. 90% off-the field is over powered and suffer because of it.
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Old 03-09-2012, 01:51 PM
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Originally Posted by 8ight-e View Post
The higher the voltage is the less the amp draw is.. to do the same job. The only way amp draw would remain the same or increase at a given voltage is if you were pushing for more. As a lipo runs out of mAH voltage drops in any application LOL (cars, planes, even trains ;P) and with ALL batteries.

Lets say the motor needs 1000watts to hit the top speed you want (geared for) down the straight this gearing now limits the system and it won't be asking for additional wattage unless you add a hill or change a variable

Voltage x Amps = Watts

7.4v x 135amps = 1000watts
6.2v x 161amps = 1000watts

As the pack looses voltage amp draw increases to make the same wattage, thus the longer the pack can hold voltage the amp draw remains lower creating less heat and increasing your run times. Temp is also what kills lipo's (makes the soft or poof), if you don't ever push the lipo past it's limit you will get more cycles.

This is not an opinion it is a fact.
Yes, I chose my words carefully for this reason. In the specific limited case of a controlled power level below the maximum, not using full throttle, you are correct. But I don't believe that is the case for many, if not most. Certainly not the point of the thread it seems to me, if one is not using full throttle the battery choice isn't terribly important if at all.

Many (most?) will use full throttle at least some of the time. In that case the improved punch and performance of a truly higher C lipo doesn't come free, but rather from increased amps and power dissipation from the battery. Driven by the higher voltage under load, the amp drain also goes up.

As the battery runs down the voltage, and amps, thus power, will all decrease at full throttle. But if voltage is held better, the full throttle power level will also be held better, leading to increased drain from the power source, the battery.

Coincidently Rick Hohwart's comments supports this, as well as news items regarding similar lipo choices such as from the recent worlds, etc. Even great drivers sometimes use the lipo choice to control the punch to some degree. That punch/power limiting occurs because the battery is delivering less energy, again draining it less quickly.

All based on physics as applied to the variables of the application, and verified by real world testing experience of many experienced battery users.

Cheers.

Last edited by Dave H; 03-09-2012 at 02:14 PM.
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Old 03-09-2012, 04:55 PM
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Originally Posted by DirtRacer68 View Post
I appreciate your opinion. I currently run the venom packs as well. I will be trying them first but I have seen so many other opinions that the orion carbon packs make their vehicles so much better. Since I ordered a orion vortex motor I thought I would find out what everyone else thought.
Well I'm a newb so I wouldnt really know but if you do notice a diffrence let us know I feel I am overpowered for a track right now but off the track I could always use more power lol ALTHOUGH I may only feel overpowered for the track because of my driving abilities
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Old 03-09-2012, 08:49 PM
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Originally Posted by Dave H View Post
Yes, I chose my words carefully for this reason. In the specific limited case of a controlled power level below the maximum, not using full throttle, you are correct. But I don't believe that is the case for many, if not most. Certainly not the point of the thread it seems to me, if one is not using full throttle the battery choice isn't terribly important if at all.

Many (most?) will use full throttle at least some of the time. In that case the improved punch and performance of a truly higher C lipo doesn't come free, but rather from increased amps and power dissipation from the battery. Driven by the higher voltage under load, the amp drain also goes up.

As the battery runs down the voltage, and amps, thus power, will all decrease at full throttle. But if voltage is held better, the full throttle power level will also be held better, leading to increased drain from the power source, the battery.
A higher C rated pack will recover from the run up and WOT much faster and with the ability to handle a higher amp draw will also lead to longer run times.

WOT has the least amp draw; it's the stop and go and build up that has the highest amp draws. The exception is if you have crazy amounts of boost or "turbo" pushing the amp draw up at the top end as well. Either way a lipo with higher C rating can handle this better.

So to answer the op, YES a higher C rated pack will provide noticable punch when under stress and recover faster and you will feel the same punch much longer through the cycle.

I think this is the answer the op wanted, I believe.
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