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Old 03-09-2013, 07:05 AM   #76
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Default My thoughts on lipo packs

To feel the difference in the performance of lipos you have to run setups that are actually demanding on the needs of a battery.

For example:

Onroad:

Running classes like VTA or USGT where we are running high turn motors the lipo packs are not nearly as important. I only notice a very marginal difference in performance overall between decent packs such as the Reedy Wolf Packs up to Revtech and EA Packs. The car has a little more punch off the corners but it does not really even translate to faster laptimes.

Now if you move up to higher amp draw classes such as 17.5 Sedan or Mod TC you will notice a much greater difference in the packs you use and the weaker and usually cheaper packs will show their weakness.

For offroad you will deal with the same problems depending on conditions.

I have ran a ton of 2wd Mod Buggy and I because I could run an 8.5 or 7.5 turn motor the packs were not that important. I actually liked some 4200 50C packs because they were smooth. There was no need for a super high end pack. However if we look at a 4wd SCT or 4x4 Mod Buggy Class once again the lipo packs would fall short if they were not good quality and puff up much sooner.

I have the ability to cycle packs up to 35 amp discharge and I have found my Reedy, Revtech & other quality packs to hold higher voltages and lower IRs as the packs age over the lower grade packs I have owned over the past 2 years.

Are the Hobbyking/Hobbypartz packs a good value... YES if they are used under conditions that are not too demanding or where you do not need every bit of power. Do the last as long and age as well as other higher quality packs... NO
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Old 03-09-2013, 07:07 AM   #77
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Pit, yes. Turnigy, zippy and gens ace, while sufficient for stock, will not cut it at Porter when you push them. They simply puff up. This tells me they won't handle the discharge loads.

In the case of some speedzone cells I tried a while back, the connections were poor and a lot of heat would generate at the 4mm plugs on the battery to the point they would deform. The Speedzone batteries were the faux- carbon fiber lipo cases, 6300 65C i Believe. I did not like that they were about 1.5oz heavier than the Reedy of similar ratings.

Again, I put the batteries through extreme abuse at Porter. My TC does close to 70mph down that straight, so it is almost not considered "normal" use. Most batteries are good enough to get the job done most everywhere. Especially in stock classes.
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Old 03-09-2013, 07:18 AM   #78
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Oh and to add, Orions are very fast, but very delicate. They puff more often than the other high end cells.

If I was to list what I can gather to be the best for extreme abuse i would list them:

tier one:
thunder power, reedy
Tier two:
Orion, intellect (pro tek), epic (orange case), high C rated carbon case cells (speedzone, etc),
Tier three:
Zippy, turnigy
Tier four:
Gens ace (they just puff up to easy, but great for stock perhaps too low of a capacity)

Again, this is extreme modified TC scenarios. Basically which battey will keep up to a 4.5 with high boost and 250 ft straight for 5 strong minutes reliably over and over again.
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Old 03-09-2013, 07:22 AM   #79
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My experience with batteries is identical with yours.
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Old 03-09-2013, 08:24 AM   #80
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Quote:
Originally Posted by CristianTabush View Post
Pit, yes. Turnigy, zippy and gens ace, while sufficient for stock, will not cut it at Porter when you push them. They simply puff up. This tells me they won't handle the discharge loads.

In the case of some speedzone cells I tried a while back, the connections were poor and a lot of heat would generate at the 4mm plugs on the battery to the point they would deform. The Speedzone batteries were the faux- carbon fiber lipo cases, 6300 65C i Believe. I did not like that they were about 1.5oz heavier than the Reedy of similar ratings.

Again, I put the batteries through extreme abuse at Porter. My TC does close to 70mph down that straight, so it is almost not considered "normal" use. Most batteries are good enough to get the job done most everywhere. Especially in stock classes.
This is why I asked the question cause as a pro level driver, you can give us a more honest answer to us not so pro level drivers
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Old 03-09-2013, 09:31 AM   #81
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Originally Posted by CristianTabush View Post
Oh and to add, Orions are very fast, but very delicate. They puff more often than the other high end cells.

If I was to list what I can gather to be the best for extreme abuse i would list them:

tier one:
thunder power, reedy
Tier two:
Orion, intellect (pro tek), epic (orange case), high C rated carbon case cells (speedzone, etc),
Tier three:
Zippy, turnigy
Tier four:
Gens ace (they just puff up to easy, but great for stock perhaps too low of a capacity)

Again, this is extreme modified TC scenarios. Basically which battey will keep up to a 4.5 with high boost and 250 ft straight for 5 strong minutes reliably over and over again.
You are correct sir.

The Gens ace,Zippy,Turnigy Comp Nano,etc are junk in my opinion.
In competition these batteries don't even come close to the performance.

The internal resistance of these cells are just to high and the voltage falls of very quickly under a 30+ amp load.

The best cells out now are the Revtech, Venom, Smc, Reedy.
This is what I found to perform the best in competition.
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Old 03-09-2013, 10:46 AM   #82
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Quote:
Originally Posted by CristianTabush View Post
Oh and to add, Orions are very fast, but very delicate. They puff more often than the other high end cells.

If I was to list what I can gather to be the best for extreme abuse i would list them:

tier one:
thunder power, reedy
Tier two:
Orion, intellect (pro tek), epic (orange case), high C rated carbon case cells (speedzone, etc),
Tier three:
Zippy, turnigy
Tier four:
Gens ace (they just puff up to easy, but great for stock perhaps too low of a capacity)

Again, this is extreme modified TC scenarios. Basically which battey will keep up to a 4.5 with high boost and 250 ft straight for 5 strong minutes reliably over and over again.

Agree for the most part with your list. I have always been curious about cell performance and have used these packs.

The cell chemistry from the different 'labels' will have different application result for mod vs. stock (super); on-road vs. off-road results. My experience for the stock based on-road classes.

Stock (17.5/13.5 Onroad) <good, better, best>
Group 1 - SMC, CRC, OHP
characteristics = lower IR, better/best avg voltage, good/better life-cycle


Group 2 - Thunder Power, Reedy, Intellect, Epic
characteristics = lower/moderate IR, good avg voltage, better/best life-cycle (TP/Reedy are best here)

Group 3 - Orion;
characteristics = lower IR, better/best avg voltage, ok life-cycle

Group 4 - Private Label

Haven't cycled EA, GensAce, Turnigy, CarbonCase OEM.

I agree with your tier 2 list for mod - absolute workhorses. I just have yet to see/purchase/use packs from that list that produce similar numbers I get from my Group 1 list.

Interesting discussion. The caveat of course is that many conditions effect results including application, methods, temperatures & equipment.

For the at-large reader - find a method that works for you in logging your packs and share your results. Not a lot of work but over the longer term you will gain a better knowledge of pack performance & program.
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Old 03-09-2013, 11:22 AM   #83
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I was thinking of going with SMC for this year of racing. Glad to see they're towards top of list. Hello Mr. Dawson long time no see.
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Old 03-09-2013, 11:25 AM   #84
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I was thinking of going with SMC for this year of racing. Glad to see they're towards top of list. Hello Mr. Dawson long time no see.
The OG RoyalRumbler - hope TX is treating you well!

One thing I didnt add to that list was price. I'll leave that up to the readers to make their own price v. value decision!
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Old 03-09-2013, 12:40 PM   #85
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Originally Posted by B.C.Ninja View Post
And lastly a question on internal resistance, how many ohms in resistance rise will create a drop of 50% in output power at a draw of 60Amps? I await the replies.

Vd=I^2 R


It depends on the voltage of the battery. Assuming 7.4, dropping to a 3.7, 1.02mOhms at 60Amps.



Shawn.
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Old 03-09-2013, 12:45 PM   #86
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Had not looked at Smc in a while. They look exactly like the previous gen Reedy so I imagine they are pretty good. I am definitely gonna order one to try out.

Good stuff here. I like hearing that what I have found is in line with what others have observed. Mind you all my testing is only done on the track.
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Old 03-09-2013, 10:58 PM   #87
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Vd=I^2 R


It depends on the voltage of the battery. Assuming 7.4, dropping to a 3.7, 1.02mOhms at 60Amps.



Shawn.
In that case 0.00102 Ohms, shit you'd better have a pretty sweet way of measuring the internal resistance then otherwise its just another gimmic to confuse people, all in all people need to run what they can afford, and usually this means newbies running a slower class only need cheap batts, once you progress up to a more full on class, you'll have a bit more knowledge under your belt and be able to make your own choices, realistically there will only be a limited amount of drivers out there that will notice a big difference between batteries, shit I run 13.5 boosted and have tried differing batteries, I lined up my $27 Zeppin against a $100 proamps and to be honest I didn't notice a thing, any difference in my lap times was purely down to hugging that corner tighter or breaking later, shit what next measuring the variance of the temperature coefficient in the vacuum of space whilst getting down on one knee praying to god for that little extra "Punch", ignore the propaganda buy what you can afford and race the bloody things as hard as you can.
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Old 03-10-2013, 09:39 AM   #88
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Originally Posted by Shawn68z View Post
Vd=I^2 R


It depends on the voltage of the battery. Assuming 7.4, dropping to a 3.7, 1.02mOhms at 60Amps.



Shawn.
Also, the way you charge lipos to get the lower internal resistance is key.
You need a minimum of 20 amp or higher charger with a 10 or higher discharger.

Store lipos at 50%.

1) Discharge lipo down to 3 volts per cell.
2) Charge at 20+ amps
3) Run

The 20+ amp charge puts light heat into the cell as it charges and keeps the voltage up longer.
Lower IR everytiime.
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Old 03-10-2013, 10:48 AM   #89
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Originally Posted by CristianTabush View Post
Oh and to add, Orions are very fast, but very delicate. They puff more often than the other high end cells.

If I was to list what I can gather to be the best for extreme abuse i would list them:

tier one:
thunder power, reedy
Tier two:
Orion, intellect (pro tek), epic (orange case), high C rated carbon case cells (speedzone, etc),
Tier three:
Zippy, turnigy
Tier four:
Gens ace (they just puff up to easy, but great for stock perhaps too low of a capacity)

Again, this is extreme modified TC scenarios. Basically which battey will keep up to a 4.5 with high boost and 250 ft straight for 5 strong minutes reliably over and over again.
I Completely agree with this list.

My friends and I have tried budget (hobbyking) to mid (Intellect IP, gens Ace) to expensive Thunderpower and reedy batteries.

We run TC, 10.5 -8.5T Boasted with tons of Dynamic timing and final full throttle turbo timing.

Of all those packs we have tried, Hobbyking packs just give up after 3-5 mins, Gens Ace and IP intellects last a bit longer ~8 mins.

When i say give up, I mean literally, when we hit full throttle on the straight and all the timing is dumped onto the motor the battery voltage just SAGS and hits soft LIPO cut off on the ESC. We would pull our cars off the track scratching our heads staring at our battery voltage on the charger which still read 3.96v per cell.... meaning the cells still held more than 60% capacity, so the only reason left why we kept hitting soft cut was that the ESC must have detected a massive voltage dip and reduced power to save the LIPOs.

Cheaper packs just CANNOT hold its voltage under sudden high loads.
While cheap LIPOs are fine for non boasted run about basher vehicles, they are utterly useless for competition.

Once we switched to Thunderpowers and Reedys, everything changed. We can keep boasting for 15 mins without hitting cut off and the packs come off at 3.85v per cell.

I've had a PAIR of 2S TP 5300mah 65C packs now for 10 months. Internal resistance remains at 2 milli ohms for both packs. Used every week... performance hasnt skipped a beat since new... Best $180 I've spent.

I've since chucked all my bloated Hobbyking stuff out.

EDIT: Back to the whole Fake C rating thing.

My Reedy Wolf Packs, 5000mah 25C out perform all the 'tier 2' and below packs of much higher 'C ratings'

In fact I reckon they are the best value for money packs. Half the price of a 5300mah 65C ThunderPower, and only slightly behind them.

I prefer the TP cases though, much tougher.
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Old 03-10-2013, 12:34 PM   #90
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Also, the way you charge lipos to get the lower internal resistance is key.
You need a minimum of 20 amp or higher charger with a 10 or higher discharger.

Store lipos at 50%.

1) Discharge lipo down to 3 volts per cell.
2) Charge at 20+ amps
3) Run

The 20+ amp charge puts light heat into the cell as it charges and keeps the voltage up longer.
Lower IR everytiime.
I agree with you that your method will give you superior results, at the cost of reducing the number of cycles the battery will last for. You can also charge the battery at 1C, and warm it up for the same results.

Shawn
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