Batteries

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AARCMCC Rule Updates – Batteries & Mugen MTC-1

AARCMCC have released through their 1:10 On Road Facebook page  a rule clarification and an update to the battery list.

Lets start with the touring car, AARCMCC have clarified the legality of the Mugen MTC-1 and it’s front bumper  As you can read below the ruling is that the bumper and the car are legal for use.

We have had some questions raised about the legality of the recently released Mugen MTC-1 touring car. The item in particular is the advertised ‘Aerodynamic front bumper’, which may contravene regulation 9.5.1.6 “Under body/chassis aerodynamic aids of any nature are not allowed.”

Following discussion of the committee, we have concluded that whilst the car in question is advertised with bumper as an “aero-shaped” component, the primary function is as a bumper/foam bumper support, not an aerodynamic device.
The intent of the regulations is to avoid home made bolt-on skirts and diffusers, not to restrict mass produced cars from competition.

As such the MTC-1 is legal for use in all Sanctioned AARCMCC events.

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In the land of batteries, there has been an update to the battery list to include Team Zombie batteries on the approved batteries list.  Now most of these are High Voltage packs, which personally I think should not be allowed on the list.  It gives easy scope for people to cheat and use higher voltages, and more work for officials who have to test the battery voltages.  That said, it is just my opinion but as my club is looking at running a state title for the first time in 2018, all I see is more work….
For those interested here is the link to the information about which packs are now on the approved list from Team Zombie  https://drive.google.com/file/d/0B8ABYMx7IGiCSlJiSEVqR2dtWjA/view and below the statement that accompanied it.

Zombie Batteries – Local Approval

We have recently had some discussions about the use of Zombie Batteries at AARCMCC sanctioned events. Having been in contact with both racers and the distributor, it’s been drawn to light that battery approval lags well behind motors. For example, the BRCA only update their lists twice a year, and ROAR haven’t updated for a while.
Having discussed this among representatives from both Electric sections (On and Off-road), we have the solution to provide a local approval.
The stipulations were;
1) Batteries must have been submitted to ROAR and/or BRCA for approval on their lists (this has been provided, to both ROAR and BRCA)
2) The batteries are commercially available for sale (they are, and have been for some time)
3) Samples sent need to be sent to AARCMCC for measurement and reference (complied with)

With this, we are happy to announce that Zombie Batteries detailed in the attached pdf are as of now legal for use at AARCMCC sanctioned events.

We are always keen to work with local distributors to aid in making sure equipment is able to be used, and if any other supplier wishes to enquire as such, please get in contact with us.

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Are you getting the battery that you paid for?

It has been interesting seeing the capacity and C rating of Lipo batteries rise and rise of late, and I have always wondered how long that increase was sustainable on the currently available technology.  Now it looks like SMC may have answered that for me!

Superior Matching Concepts, or SMC, is a brand of battery that I was shown by then fellow racer Scott Guyatt as a good bang for your buck battery much akin to the Intellect batteries I am/was running at the time.  I am afraid I am yet to buy any, but I am in need of some younger batteries so whey are moving up the list in priority and these are at the top of the list.

However a post on their facebook page today caught my attention so I thought I would re-post it for our readers to see. The complete statement is included below.

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.

Source: https://www.facebook.com/smcracing?fref=nf
Website: http://www.smc-racing.net/
Australian Stockist: http://www.coast2coastrc.com.au/