The truth about batteries.

[OhioSuperSport]

I thought I would share this. Danny with SMC batteries posted this.

I'm making this post to try and help educate everyone about how crazy the Lipo ratings have become and are pretty much useless. I know most of you will appreciate this post and some will think I'm just using this to promote SMC but this is really to open some eyes.

First let me explain the fact that their is no true C rate testing standards. Some factories use mAh retention and others use heat and voltage curve to determine the C rate. Every factory knows the C rate of their cells based on one of these 2 methods of C rate testing.

When I started testing and buying Lipos 8 years ago the C rates were 10 to 20C for car packs. At that time the factories were giving true C rates based on their testing method for C rate. Within a few years C rates doubled but this was just marketing to try and sell more packs and make more money. Now 8 years later it's even crazier with some outrageous C rate claims and mAh has also started to increase on the labels but not on the cells. In my opinion 80% or more of the packs being sold in car market today have a true C rate of 15 to 25C using the heat and voltage curve method for C rate testing. Using the mAh retention you can add 5C. There are some 30C and 35C packs available but these are very rare and cost more to make.

C rate is the amp rate at which the cell/pack can be discharged at. So a 5000-20C can do 100amps. A 7200-20C can do 144 amps and so on. IR(Internal Resistance) is directly related to a cells ability to handle amp loads. So it's not possible for a pack to have higher C rate and higher IR. This means a 7200-20C has to be lower in IR than a 5000-20C. The size of the cell also limits it's mAh or C rate/IR. In car packs with hard cases we're limited by the size of the case. This means if you want to increase mAh you must increase IR or vice versa. A 7200-25C will have higher IR than a 6000-35C. The 7200 will be able to do 180 amps and the 6000 will be able to do 210 amps. Only way the 6000 can provide more amps is to have lower IR.

Now that we know this if true C ratings would exist the consumer/racer would be able to know what pack better suits his needs. Unfortunately this isn't the case so there really is no way for the customer/racer to know. SMC is no different than others as we also use inflated C rates as we have no choice. If we would use true C rates we would be out of business. What we do try and do that is different is make sure that our ratings mean something. For example our 5000-40C will have higher IR than our 5000-50C and so on.

Here is something that I find interesting and frustrating at the same time. Some of our competitors buying the same packs we do offer them with higher ratings. This leads to some customers buying these higher priced packs instead of ours. Here are 2 examples. The 4400-60C shorty which we sell for 29.95 is being offered as a 4600-90C at 44.95 and it's the exact same pack that we offer. The 7200-60C-2S pack we offer for 39.95 is being offered as a 7600-75C for 64.95.

Something else interesting is that a customer who bought one of our 5000-40C-2S packs at 24.95 compared it to a 5450-120C-2S pack at 129.99 and told me that our 40C pack ran longer and faster in the same vehicle and the 120C pack was new to make a fair comparison.

Now that we know C rates are all made up and it's actually getting a bit ridiculous to claim even higher C rates it seems like in the past few years mAh is now what is being inflated. Recently I tested a 7000-1S pack that only put out 6222mAh. I will admit some of our packs also have a bit lower mAh than claimed but this is due to the model being improved to provide lower IR. If you drop the IR the mAh drops.

I hope this post can help some of you not fall for all the BS and hype and don't be surprised if SMC starts releasing higher rated packs to try and keep up as it's very frustrating to under rate our packs and lose sales.

[The Violator]

Maybe SMC should get a blue star and pimp his products here himself. The post says in other words, everyone else lies, so we are going to lie also.

So instead of taking the high road, they are going to sink to the level they call other companies out for.


I have some of his batteries. All in all, they are OK. Not any better, IMO, than any of the hobbyking batteries I have been using. And not as good as GensAce. Out of 5, a single battery died rather quickly. My 4 year old Gens still work fine.

[gunder463]

can you really believe anything anymore?

[MattTheGenus]

Originally Posted by gunder463

can you really believe anything anymore?

That got meta pretty quick LoL

[Wilspeed]

I set several Track, State and Regional records running SMC Batteries back in early 2K's in Oval. Have a hard time NOT believing what the man has to say....

[Johnnysplits]

I call bullshit. I've tested four different batteries...same C rating, same mah and the results were pretty close. Out of a Gforce elite series, GensAce, Zippy, and Turnigy nano-tech, the Turnigy had the least resistance...0 to 1 mohm/cell and had the least amount of voltage drop. As an example, most people buy 5000mah 2 cell lipo's. You are being ripped off if you pay more than $35 for one. Period.

[Crank]

I'm not so much concerned if my batteries are really putting out the claimed C rating as I am about how many full capacity charge/discharge cycles they will go through.

I can work with a 20c battery that claims 60c, but get a bad cell after what I would call a minimal amount of charge cycles and you're fun is over.

[The Violator]

Originally Posted by Wilspeed

I set several Track, State and Regional records running SMC Batteries back in early 2K's in Oval. Have a hard time NOT believing what the man has to say....

Pulling huge loads with those brushed motors and Nicad packs.

[Duuuuuuuude]

Originally Posted by The Violator

The post says in other words, everyone else lies, so we are going to lie also.

Pretty much. But as he said, if they don't, they'll lose the market. Consumers are lied to all day every day, the trick is to ignore the gimmicks and use a little common sense.

Once you realize that ALL rc lipo battery cells come from one of five factories in China, the brands that make claims that theirs are leaps and bounds above everyone elses become highly suspicious. I don't need to name names here.

Originally Posted by Johnnysplits

I've tested four different batteries...same C rating, same mah and the results were pretty close.

I've seen several more than that, and for the most part, you're right. Pick a brand that is comparable to most others in price and rated performance, and chances are you'll do well.

Originally Posted by Johnnysplits

As an example, most people buy 5000mah 2 cell lipo's. You are being ripped off if you pay more than $35 for one. Period.

Truth.

[WHITE-TRASH]

Originally Posted by The Violator

Pulling huge loads with those brushed motors and Nicad packs.

Nahhhh they could have been NiMh.




Long live my cheap LiPo's. They keep coming back for more after I abuse them.

[RcBro]

Gen Ace for the win. Rumor has it they are looking to support the forum soon too.

The battery debate is just as bad the the LED lumen debate. They're all picked from thin air. I used and puffed more name brand expensive packs then any of the cheap ones.

[Dad,Canyoufix?]

Don't pay for C rating, got it. Like I would ever consider throwing a high$ lipo in my scx submarine or clumsy goat wraith
Thanks guys, good info to keep in mind for when a high power set up is in mind.

[Olle P]

To me (and most other R/C car drivers) it's the peak current rating that matters much more than continous delivery.
Batteries are typically rated for current peaks up to twice the "continous" rating, whereas in use the peaks are more like ten times the typical draw.

Originally Posted by Dad,Canyoufix?

... good info to keep in mind for when a high power set up is in mind.

Or when you want as light a battery as possible for the ultra light comp crawler!

Here's the relevant issue for crawlers:
For a rig that draws ~30A peak, <3A average and needs 10min runtime on a pack, what's the least acceptable energy content (capacity) and (true) C-rating?
The math is quite simple: 500mAh and 60C peak current.

Any comments on the peak C-rating of batteries?

[OTHGbronco82]

Originally Posted by RcBro

Gen Ace for the win. Rumor has it they are looking to support the forum soon too.

The battery debate is just as bad the the LED lumen debate. They're all picked from thin air. I used and puffed more name brand expensive packs then any of the cheap ones.

I had a max amps pack that puffed after 4-5 uses. Have some gens ace lipos that have 2-3 times that amount and haven't had a problem yet. Not even a little puffing. And I bought like 5 for the price of the max amps.

[OhioSuperSport]

I'm not peddling anyone's product. Just sharing some good facts I thought would be beneficial to others is all. No need to jump on the soap box so soon.

[Odd-M]

I run some $12 Turnigy batteries and they are still just fine after 30-40 cycles in my scalers. Will never buy anything expensive for regular brushed motors with this use.

But with brushless I've stepped up a couple notches in ratings. Strange thing I've experienced is a noticeable difference in performance between brands, and that the one with the lowest C-rating (amongst 5000mah-ish 2S all of them) actually outperform the others in speed and acceleration in my basher.

[gunder463]

Originally Posted by OTHGbronco82

I had a max amps pack that puffed after 4-5 uses. Have some gens ace lipos that have 2-3 times that amount and haven't had a problem yet. Not even a little puffing. And I bought like 5 for the price of the max amps.

lol maxamps, biggest bullshit in the battery world

[svt923]

Originally Posted by Duuuuuuuude

Once you realize that ALL rc lipo battery cells come from one of five factories in China, the brands that make claims that theirs are leaps and bounds above everyone elses become highly suspicious. I don't need to name names here.

My dad works for one of the big Japanese electronics companies as the head of environmental regulations and deals with the global battery market on a daily basis. He was telling me that between Panasonic, Sony, Samsung, Sayno, and one other company I can't remember, they produce 85% of the world's lithium based batteries. The remaining 15% of the world's batteries (including all of the R/C batteries) come from small Chinese factories. Support whatever company you like but don't think that any R/C battery is actually high quality in the overall world of lithium-based batteries. I would imagine that R/C batteries are all picked from the bottom 10% of battery quality since the market is so small. Even in the NICAD and NIMH days, all R/C batteries were essentially those that weren't good enough to be sold to the power tool industry.

[wings_of_fire]

It all comes down to the materials used in Lipo chemistry. There are various grades of metals, compounds, chemicals according to purity and prices vary according to their grade. When chinese factories want to make a profit in competetive market and they know the customer is not going to send it for a chemical analysis they get pretty sure to take a way that increases their profits unethically. The result is poor choises of materials and hence a poor quality battery. Another way for poor quality is when the bulk buyer asks manufacturers for a high profit product.

The manufacturing sector has its own issues. The supply chain has its own issues. The customer gets issues because the manufacturers and supply chain had issues.Unethical business practices ruin a customers day.

Ever wondered why most of those mass manufactured crap fail in our day to day life? How much money we spend on them every time they break? Remember those old days when consumer products would just not fail. Where did those manufacturers go that made quality products and who had customers gain in mind? It is a sorry state in todays world that people who are honest in their business practices get run over by the outnumbered dishonest ones that have nothing in their mind other than profit making for themselves.

[EeePee]

Ahhh, the yearly battery BS...

I think GensAce or Hobbyking or whatever they are, pay people to post things of this nature. They probably own Max Amps, too.

Oh yeah, remember those battery tests Chris The Battery Man did?

No battery manufacturer I've used has been perfect. I don't expect them to be. What does bug me is the HUGE price gap. It's not like we're talking about Hyundai versus Ferrari here. These are batteries, of the same chemistry type, same size, same voltage... overheads must kill some people's sanity.