60C really?

Originally Posted by austinelse

Using this method, I feel that it is much better than just a C rate like the majority of the manufacturers are using. There is NO STANDARD TESTING METHOD TO ESTABLISH IT!

Austin, why not use the constant C rating if the majority of manufacturers are using this method. It seems that if MA were to use this method it might help to establish a "standard".

[BrianG]

It would behoove them to send a sample pack to a respected third party for verification. Some people simply have a bad taste in their mouth from past experiences and it would lend a bit of credibility to have someone substantiate their claims.

[BrianG]

Thanks for posting Austin. I have to agree there are no standards. Enthusiasts have grown accustomed to seeing continuous C and burst/surge C, and they know how these values perform in the real world, so it only stands to reason they want to see everything rated the same way. Consistency is key.

Burst rating does makes sense though. If you go by the runtime vs pack capacity calculation, most people are running an average of under 20A in a typical 8th scale setup, but the bursts are 6-8 times higher.

I'm not gonna flame your product, but I do have older generation cells (5Ah and 8Ah) that do not come close to achieving the rated output without heavily dropping voltage and increasing temperatures. I'm sure others have similar experiences and it can make one leary. I think that once people substantiate these new claims, they will feel more comfortable. However, I do think prices are kinda high, especially with the new Hyperion G3 series which perform exceptionally well for less money.

[Semi Pro]

Originally Posted by BrianG

Thanks for posting Austin. I have to agree there are no standards. Enthusiasts have grown accustomed to seeing continuous C and burst/surge C, and they know how these values perform in the real world, so it only stands to reason they want to see everything rated the same way. Consistency is key.

Burst rating does makes sense though. If you go by the runtime vs pack capacity calculation, most people are running an average of under 20A in a typical 8th scale setup, but the bursts are 6-8 times higher.

I'm not gonna flame your product, but I do have older generation cells (5Ah and 8Ah) that do not come close to achieving the rated output without heavily dropping voltage and increasing temperatures. I'm sure others have similar experiences and it can make one leary. I think that once people substantiate these new claims, they will feel more comfortable. However, I do think prices are kinda high, especially with the new Hyperion G3 series which perform exceptionally well for less money.

+1 the new Hyperion g3 vx are amazeing (this comeing from a guy that has 6 MA packs lol)

the 4cell 4200 is 65c burst for only $133

and you have to love the Hyperion 5c charge rate too

[zeropointbug]

Originally Posted by Semi Pro

+1 the new Hyperion g3 vx are amazeing (this comeing from a guy that has 6 MA packs lol)

the 4cell 4200 is 65c burst for only $133

and you have to love the Hyperion 5c charge rate too

I hear you man, I bought my (2) 3s 4200 VX's for $200.


Austin, I, like BrainG and many others here will agree that there are no standards for C ratings. You can preach about your testing methods but here are the shortfalls:

-First, I don't even know of a battery pack that can deliver 60C at WELL OVER 3.2v/cell, I am not even sure the ThunderPower 40C' packs can do that!

-Second, your 4660 surge watts is based on what? That's 3.7v/cell, CAN your packs do 3.7v/cell at 60C? LOL And 60C seems like a very arbitrary number, no?

-Third, no body here (no smart person) would design a setup based on the surge watts, NOT A ONE. You always, ALWAYS make your battery choice based on continuous C rating, although, I admit is sometimes loose/false ratings. SURGE WATTS ARE IRRELEVANT.


My own setup, I don't even go above 25C discharge with a 6s Hyp. G3 35C/65C pack... why? because I want performance, not being able to say I power my rig with 60C+ bursts... and a few runs later have my battery overheat, puff, or even catch on fire in the most extreme case.

In the end, no matter what you say, it will take time for people to get the bad taste out of their mouths like Brian said; I hate to say it, but no one trusts Maxamps anymore. I will take some independent testing to prove otherwise, and also show us that your packs are worth twice as much as the one of the best packs out there.

[zeropointbug]

Austin, I would very much be willing to test a pack of yours if you would donate one for this purpose.

All I would need is a 6s pack with a capacity of 1750mah to test the 60C rating.

Is this possible to do?

zeropointbug,

1. We explain in exact detail our method for determining these ratings. You can test the packs the exact same way that we do and you will find the same results.

2. The surge watt rating is simply a number to help people determine the correct pack to choose based on their motor and speed control. Surge watts are not only relevant, but it is the way that the motors are rated and the only correct way to determine what battery to choose without having a watt meter hooked to the motor.

3. No smart person would determine what battery to use based on C rating since the C rating is just a number that the factory picks. It does not mean anything.

Of all the lipo manufacturers out there, I believe that MaxAmps has the least to "prove". There are many independent third parties that I have listed in the previous thread, thousands of happy customers over the last 5+ years, and the readers choice award in RC Car Action and RC Driver.

You may not realize it, but the reality is that more people trust MaxAmps than any other manufacturer. Your statement is just completely wrong. Your personal opinion is not what "everyone" thinks.

We realize that it will take time for people to understand the new method of rating packs but I believe that over time you will see other manufacturers using this same method. It is much more simple and easy to understand.

I posted here to help explain the new method of testing our packs. Thats all. I am sorry that for some reason you personally feel like we are not "trustworthy" and I take that very personally. I have worked hard to build this business on a rock solid foundation of integrity. If you have had a bad experience with us in the past I would love an opportunity to earn your business in the future. Feel free to give me a call personally to see how we can earn your business.

Best Regards,

Austin Else
CEO MaxAmps.com

Again, I'm a bit confused, you state that, "No smart person would determine what battery to use based on C rating since the C rating is just a number that the factory picks. It does not mean anything."

Yet your marketing states, "As you racers know, the most important factor for your batteries is voltage under load. This LiPo pack boasts a 60C rating for all your amp hungry racing setups. It will maintain higher voltage under load than any other LiPo battery pack on the market."

This is rather confusing to me.

dezfan,

My whole point is that the constant C rate does not mean anything. Some manufacturers test loose cells in a pack and then rate the pack based on the loose cells. Some test with 5 awg wire that is an inch long soldered directly to the tabs of the cells. Some consider it a constant rating if it lasts more than 10 seconds at over 3V. Some allow temps of 160 degrees. Some use cooling over the cells. Some test the cells starting at 50 degrees. THERE IS NO STANDARD.

Brian,

You can tell us your opinion of what the standard should be, but no matter how much influence you think you have, all the manufacturers are not going to "conform" to your standards.

You stating what you think the standard should be will not make it the standard. Thinking that your standards are the "standard" is crazy.

I have struggled with this whole C rating thing ever since the beginning when I would get a 20C cell from 2 different manufacturers and the performance would be completely different from one to the other.

That is the reason that we are changing it. At least this way I can feel like we can honestly back up our claims based on anyones "standards".

As an example, I have talked with a customer who thought that the standard should be "Constant C rate should keep the pack under 100 degrees, over 3.5V and should deliver the full rated capacity". I can not argue the point since there is no standard.

All we can do is tell you what the rating is, how we got to the rating, and how to determine what motor to use the battery with. If you smoke our pack on a motor that has a surge watt rating lower than our packs surge watt rating, we will replace the pack under warranty. It is that simple.

-Austin

Brian,

I am sure that you realize that like every other lipo out there, our packs are constantly improving in performance.

Your point regarding voltage under load and pack temperatures is exactly the same point that we are making with this rating system. "C" rates are just an arbitrary number without much more data.

Frankly, I agree 100% that there should be a standard. I would love for every manufacturer to rate the packs by a standard 3rd party method. That simply is not possible at this time. A 10C pack could perform exactly the same as a 60C pack depending on what "method" they used to establish it. As you can imagine we have tested cells from many, many manufacturers. Some just call it 40C because thats what other people call theirs.

All we can do is be honest about how we rate our packs and what method we use to test them.

As you said, the proof of how our packs perform comes from reviews by our customers including Traxxas, Castle, Novak, HPI, Axial, Caster, etc. That along with the fact that we were voted best battery in RC Car Action for the last 2 years back to back and best battery in Driver.

One final point to address your pricing concerns. We offer a membership program on the website where you can save up to 20% off your packs. We could pay someone in China 25 cents a pack to build the packs for us like others do. I prefer to pay people a fair wage here in the USA to build the packs exactly the way you want including plugs, taps, wire size, wire length, skins, hard/soft case, and configuration.

We are also the only manufacturer who builds your pack to order and guarantees that the cells are factory fresh within 3 weeks. We have the best customer service in the industry and are available by phone and email 7 days a week. We have the best warranty in the industry.

We are the industry leader for a reason. Our goal is for every MaxAmps customer to become a raving fan.

Some people prefer to buy the cheapest pack, install their own plugs, get no support, long shipping times, etc. That is ok. We can not be all things to all people.

We can guarantee the best value and I can assure you that after all the "cheap" manufacturers go away, we will still be here to support our customers with the best products and the best service.

Best Regards,

Austin

[BrianG]

Before this thread goes any further, I would like to remind everyone to keep flaming posts to yourself. Stick to facts. We don't want to alienate anyone.

That said, I would like to address the idea of matching motor surge watts with battery surge watts. Motor surge figures are typically based on the power drawn for a specific amount of time, repeated with a certain frequency, or duty cycle. And even then, the actual surge power can be substantially greater than the rating depending on MANY factors. A motor does not have some kind of "power regulator" which limits the power; those specs are based on various motor characteristics, most notably efficiency and surface area (for dissipation).

Anyway, even though the continuous rating may be somewhat meaningless, I think it would be advised to add that rating to your specs, if for no other reason than to reassure people used to the "old system". Failure to do so may be percieved as hiding something.

Standardized testing has been discussed here numerous times, and most people can agree on some variation of the following testing procedures:

- Continuous rating: Specify the continuous current that can be drawn from the battery along with the voltage and the temperature at that current. Example continuous spec would read something like: "Cell X rated for 100A continuous current @ 3.4v/cell for 90% of the discharge cycle, with no more than 30*F rise in temperature over ambient".

- Burst rating: Again, specify the current that can be drawn from the battery along with the voltage and temperature at that current. But, add the frequency and duration of the bursts. Example spec would read something like "Cell X rated for 200A bursts @ 3.4v/cell sustained for 0.5 seconds, occurring every 10 seconds, for 90% of the discharge cycle, with no more than 30*F rise in temperature over ambient".

Alternately, plot pack resistance graphs vs temperature over various discharge rated. We can then calculate voltage drop on that alone.

[Bondonutz]

No Flames here, I just don't beleive it.

[suicideneil]

C rates are not arbitrary in my mind, they are a number that can be tested quite easily, especially given that Maxamps reportedly are in possesion of the necessery equipment.

You hook up the pack or cell to the equipment, increase the load until the voltage drops to various predetermined levels (3.2v per cell, 3.7v per cell for example), then plot the graph like you would when using an Eagletree (something alot of people do actually own).

With that graph, you can see how many amps are being pulled to produce the predetermined voltage levels, then its just a quick bit of mathes to see if the stated C rating is accurate or not:

4200mah lipo cell, rated for 35c, needs to put out 147amps @ ~3.2v to be concidered having an accurate C rating in my book, and most other people's books.

So, lets look at one of your graphes:

http://www.nitrokillers.com/showthread.php?t=1527

You state that you test the 4200mah 35c by hooking it directly up to the CBA and apply a constant 119.8amp load. So, we look at the voltage the lipo drops to, and its around 3.2v for the whole discharge, gradually dropping off to 3.0v around the 3.5 minute mark.

Now, if we do the mathe:

119.8 / 4.2amps = 28.5c.

But wait, I thought it was a 35c lipo, so that would be 4.2amps x 35c = 147amps.

Result = false ratings. And 130 degrees F is excessively hot, 120*F is accepted as the safe maximum. The high temperature would indicate thew cell is being over drawn at even 28c, let alone 35c...

The lack of discharge graphes on the Nitrokillers forum just adds weight to the arguement that MA over rates its packs, and doesnt want people seeing how they really perform. New cells, old cells, that isnt the important thing, as old cells were clearly over rated, but so why should new cells be any better?

Why the secrecy over how the cells perform if they're so good?
Why the secrecy over where you get the cells- I doubt anyone is going to swoop in and steal your contract with them, although...
... why the unreasonably high prices? I understand labour costs are higher in the states, but it doesnt cost $150 to stick on a piece of shrinkwrap and power connectors, surely?

And what about this little gem?

http://www.rc-monster.com/forum/showthread.php?t=21904

Granted they arent 100% identical, but 4x the price?

I would be tempted to buy some MA packs and compare them to my Zippies, and other people surely would too & compare them to their Hyperions and whatnot of a similar spec, but given the curious/vast price difference, I'll pass.

Originally Posted by suicideneil

I would sack Jason though, or reign him in, as his Nazi style moderation techniques ("if you dont agree with me, or say that another brand might perfom better, I'll ban you and delete the thread") do nothing for people's opinions of you or your company...

I must say, that all dealings I have had w/ him have left a bad taste and contribute substantially to my not purchasing from MA.

Just wanted to say thanks to Austin. It takes guts and confidence in your products to post as much as you do. I used to believe a lot of the hype I read on certain forums or threads but on any given Saturday, when I look around at what other electric guys are running at my Local track, more are running MaxAmps than any other brand. That speaks volumes to me.

I think there is room in this hobby for many companies to thrive. We (customers) should celebrate the improvements that each vendor brings to the table. They push each-other to do better. Forgetting the 60c burst rating, these new packs are the first hardcase 4s packs from MaxAmps - that's a step in the right direction!