srt10

My Feedback: (20)

It just blows me away of how cheap these packs are!

piddlefoot

l cant believe people actually try to compare LIPO to Hydryde, what a JOKE.
LIPO is far superior for RC powering of high torque motors.. Period. Nimh just are junk.Like Ni-cads. Good for the transmitter is about all......And l dont recommend rechargables in a transmitter either ! Go alkaline.......
Batteries in the Lithuim range will forever be getting cheaper. Nimh will not get much cheaper because of the prosses thats needed to make em.
l want titanode batteries.Think thats what there called.100 times the power of LIPO ! 100 times ! L O L !
l drive for half a day flat out when they come online on one set of batteries ! hahahaha all the guys that argue, nitro cars just pull up, fuel up and keep driving are gunna have there last point of merrit snatched out from under them soon !

Chris_RC

Running brushed or brushless, they are just about the same performance wise. My co27 is just as powerful, if not more than my Novak 17.5 (same class motor). The nimh's and lipo's both perform the same, and the punch of lipo is not because the battery is more pwoerful, it is because of the weight savings. Put a few ounces of lead weight on to equal nimh and you are back to square one.

piddlefoot

br/>A LIPO cell the same size can hold 30% more energy [mah] also has a discharge rate of around double of your Nimh batteries.And is 1/3 less weight. Will discharge its full charge with less heat than a Nimh, and faster. Pure performance.
A brushed motor is inefficient compared to a brushless one, ie, the batteries will last longer on a brushless motor.Power is about the same until the control armature heats up in the brushed one, then the brushless one has more power and efficiency and less wear.

Your comparisons are flawed.

LIPO and Nimh DO NOT perform the same unles your using them for a very low draw , like a wrist watch, then your Nimh batteries are better, but for RC high loads /high draws, LIPO is far ahead in performance. Less internal resistance, and less heat, for more power discharge every second.

We shall not get into price, for LIPO own.......

studysession

But - Right now those prices look good.

MCSRacing

My Feedback: (2)

man chris ya can tell'em for ever and they wont listen ... i can run my nimh and make the podium every time unless i break. but i do prefer to run lipo's for the weight savings.

Chris_RC

As do I. The car feels so much more nimle, especially if you are running a stock motor where every once of weight makes a difference. But if you are running a Slash with a super fast motor, the less weight could be a bad thing as they already don't have much traction. That is where I woudl throw a nimh in, or add alot of weight.

cenracer1

This is only because the motors CO27 and the Novak 17.5 are the same class.. the Novak is designed to have approx the same power as the co27.. knowing this it would make sense that the Lipo and the Nimh batteries would be similar in performance, weight excluded...
But... That's not what we are talking about here.. this topic was about the batteries themselves, not the motors... If you take the same motors that do not tax the capacities of nimh batteries and run them with lipo's.. the only difference should be the .2Volt difference between the lipo and Nimh packs and the weight... If you are getting no difference in performance, then operator differences have to be taken into account...

But when using the same principles and applying them to high powered brushless motors... the Nimh batteries just can't deliver the amps needed by the esc to run the motor to its full potential... Plain and simple.. Every response to the contrary has been by racers who are using stock spec (27 turn) motors or 19 turn motors.. The brushless motors we run are in the high output class far more demanding than what you are running or your batteries can provide.. I tried to run my Rustler when I first got it with very good Nimh batteries and wasn't impressed.. the motor would get to a decent top end, but off the line was an exercise in futility.. even turning off the LVC did nothing... Lipo's ... first throttle pull cost me a new custom paint job as the truck backflipped onto its lid... can anyone say wheelie bar...

For myself and obviously alot of others, we will stick with Lipo's... what more could we want... we get Power, run time, weight savings and now even price... Nimh because of the declining market share have gotten to the point where anything considered decent is too expensive especially when compared to a cheap lipo that pound for pound blows it away...

studysession

Everyone Stop taking it so personal just because other people have different opinions.



THANKS!@

piddlefoot

Well the topic is about zippy vs high end, l have Max Amps batteries, and my cheapo Turnigy and Rhino packs, max amp are expensive, turigy and rhino are dirt cheap, cheaper than Nimh in alot of cases, so there a fair comparison, so to start, not happy with Max Amps, good battery, no question, but very high priced.
The Turnigy ones punch as much oompf as the max amps ones, run just as long, stay just as balanced, l dont understand why Max Amps are priced so high, they must realise the competition is getting greater in the LIPO industry. Surely they will drop in price sooner or later.
The Rhino packs l use, l have had no problems with, l balance every LIPO every time its charged.
Rhino packs are about 15 bucks a pop, how can you go wrong ?
30 $ for a blistering revo 1/16th.
Or compared to 2 x Nimh batterys, the traxxas type 1200mah 7.2v , which are 20$ each at Tower, 40 $ to go slower !

11.1v 5000mah LIPO turnigy 29$ each........

11.1v 1550mah LIPO rhino 15 or 16 $ each, cant remember.

Access

Maxamps is not a good representative of expensive LiPos. If you really want to compare to the best brands out there, use something like thunderpower. Expense alone does not denote quality.

Also I hate to say it but I see a lot of posts in this thread where people really don't appear to know much real about the actual electric / electronics side of things. Like the basics of how a battery is modeled in high-power dynamics. People either need to take a step back and learn some basic applied power electronics (applied = useful), before trying to talk about it in depth or use the theory to 'prove' something. Or, just talk about your own experiences (and no theory). But, don't try to relate your own experience to the theoretical side of things unless you really know at least the basics of the theoretical side of things.

http://hyperphysics.phy-astr.gsu.edu.../dcex6.html#c1

This above link describes the simplest theory (internal resistance model) and it often times gets pretty close to reality.

http://hyperphysics.phy-astr.gsu.edu...autbat.html#c1

Another example applied to automobile batteries.

http://hyperphysics.phy-astr.gsu.edu...atbulb.html#c1

A (representative) example of weak batteries driving light bulbs.

The emphasis here is that a better battery is _always_ going to be better, even at lower currents draws. It's just not going to be as much of a difference, again voltage drop is linear and actual power delivery is a bit more complicated, but for small delta V's it's still pretty linear. It's not like a LiPo and a NIMH will magically perform the same side-by-side until you get to a certain amount of current after which they diverge.

piddlefoot

What are you on about, is that ^^ for me ?
Thats all real world experience ........ ?
l do actually understand electronics, even built a small tesla coil, anyways.
Maxamps are regarded as 'one' of the better batteries, l agree theres heaps of others out there and better but l dont own em so l can only go from what lve done here. A 150$ battery Vs a 29 $ battery was my point.

studysession

piddlefoot -
That was not intended at any one person. That was intended for the entire thread here. No body should take any of these posts personal.



THANKS

Access

piddlefoot, I didn't want to single anyone out, I'm just saying don't try to apply the theory to reality without first taking the time to understand some of the simplest theories out there, that's all. I see it being done a lot in this particular thread. The concepts being dealt with here are really very simple. But people basically seem to be doing something akin to making up their own theory to justify what they see in reality. There is nothing wrong with saying what you see in reality. But don't try to apply a bad theory to justify it.

I guess my point could be summarized like this:

If someone tells me "I drive this (tamer) setup with NIMH and LiPo. It seems to handle the same either way. I drive this (extreme) setup with (the same) NIMH and LiPo. It performs noticeably better with LiPo."

I would say there is a difference between the between the NIMH and LiPo even in the case of the tamer setup. The user may not be able to identify that difference, but it is there. We know it's there in the tamer setup b'cos the difference was noticeable for the more extreme setup (this is what the most basic battery / internal resistance theory says a battery is modeled as a 'perfect' or 'ideal' battery (voltage source) in series with a fixed resistive value). The only difference is that, in the tamer setup, the difference becomes to small for the user to notice.

And someone who reads this may be saying "Why does it matter if it (the difference) is there but I can't see it?" And that depends on you or what you're doing with your vehicle. If you're just driving around for fun, or bashing, it doesn't. You can have just as much fun either way. But if you are competing in any way, ie. racing, in a really tight race, that little bit of unseen difference might make all the difference between the winning and losing. An unseen advantage, you can't tell it's there, but it still affects you in the outcome of the competition.

And when I say NIMH and LiPo above, you can substitute any inferior battery and any superior battery. All else being equal (capacity, voltage, etc.), if the only variable is current draw, one will _always_ perform better than the other.

As for the Zippy question I think it is pretty elementary. Even if the Zippys are inferior to the best batteries out there, the difference in cost is just so great. The only real need for those "super high-end packs" are high-end competitive racers. When batteries are a commodity you can just load up on capacity and get your performance that way. Ie. an 8000mAH Zippy is probably going to perform better than a 4000mAH thunderpower just b'cos the Zippy is so much bigger in terms of capacity. 20C on the thunderpower would only be 10C on the Zippy. The racer can't necessarily do this b'cos he wants his CG as low as possible and then weight.

studysession

That is a good way to summarise it Access.

Now just can't wait for the snow to be cleared to try out my 2 new Zippy 5000mah batteries that I ordered and compare them to others I have. [&:]

studysession

Some here might like this thread as well -


http://www.rcuniverse.com/forum/m_92...tm.htm#9248298

SPC Racing

...............

SPC Racing

................

rebuilder

The number comes from individual companies posting it.................................why rate your batteries at less then you are saying they can put out? Doesnt make alot of sense when you are touting your product. Heres an example:

High Capacity High Power Nickel Metal Hydride Battery Pack for RC cars.
NiMH technology enables convenient charging at any time. No cell memory effect. No need to fully discharge before recharging.
High power delivery with 40 Amp maximum discharge rate.
Uniquely designed & manufactured for high RC Racing performance.
6 months warranty.

SPC Racing

..............

studysession

Certianly can come across that way.

As for the original question that had nothing to do with NiMH's -
Can't wait to test my 2 new Zippy LiPo's against my other packs and see for myself how they perform. Right now to much snow to take my RC's out.

Mean time - if that sale for the 3S 2200mah packs are still $12 next payday, I might get couple of them as well for bashing.

rebuilder

NO......................complete mis-understanding....seriously..................I should have said when "one" or "a" random company is doing that...........not you specifically...........i forgot i was conversing with a company rep............my bad. I didnt even go to your site to see what you rate at. I just picked a site i knew of that posted these type of ratings.

SPC Racing

I understand, no problem.

MCSRacing

My Feedback: (2)

this thread makes my head hurt ... like beating it on a brick wall .............[:'(]

studysession

I have been discussing this topic with many in the last few days in relation to this thread.

Everyone that has read the thread knows I purchased two of these and have received them. Won't be till the snow is gone before I can do anything with them. [&:]
5000mah 2S 7.4v 20C Zippy LiPo Battery I paid less than $20 for each of them
http://www.hobbycity.com/hobbycity/s...idProduct=8578

What does a "so called" similar good pack go for on the average? I want 2 of something comparable to what a bought to compare equal, side-by-side and do another video like I did below. Run two of the Zippy's through and then run two of the good brand though and post so others can learn from it.




The matched cell or better quality cells does make a difference. Here is a video I did to compare two different pack sold by UnitedRC few years back while they were still in business. You will see that his matched XTreme GP1100mah cells made a big difference verse the 1000mah sport pack he gave me. So no one needs to explain to me the need for good quality cells, I fully support and understand they make a HUGE difference.
http://www.rcuvideos.com/video/Mini-...pner-Speed-300

Back when I used to R&D some of the custom brushless controllers my sponsors would make for me - the quality of the cells, gage of the wire from the battery to the controller, Dean’s connectors were all necessities.



Great dialog here - lets keep it going....