Answered: Battery Charger - Rule R13e

My team had a concern regarding rule R13e. It states that the only legal means for charging a VEX 7.2V Battery Pack is via one of the following VEX Battery Chargers: Smart Charger, 276-1445; Smart Charger v2, 276-2519; 276-2221 (discontinued), 276-2235 (discontinued). All other chargers are strictly prohibited.

A few years back, we were in a competition where we were using the VEX chargers listed. Because of the fast paced scheduling of the qualifying rounds and the amount of loads we were placing on our batteries, we noticed that they were beginning to fade during each match. As a response, we began charging our batteries between each match. The problem with this is that the batteries were getting heated during the event, and as a result, they would not hold a full charge for the next event. The charging also contributed to maintaining the high battery temperatures that crippled our team’s battery capacity. After that event, my teams started using some digital peak chargers that allow us to specify the capacity of the batteries, the current (charge rate), and even battery chemistry. This enabled us to “top off” our batteries between rounds while maintaining lower battery temperatures, thus solving our problems of low power during the event.

The new rule that prohibits other chargers from being used only pushes teams into the paradox of charging batteries to maintain charge but at the same time keeping battery temperatures high thus lowering overall battery capacity and possibly shortening the overall battery life. I know NiMH batteries are fairly robust, but each time they are heavily fatigued, it shortens their battery life and lowers their capacity. I personally don’t like the idea of having to purchase new batteries because they were overcharged, overheated, or completely depleted to try and stay competitive.

If you have a laptop and you lose the power supply, you don’t throw away the laptop. A proper solution would be to find an adequate power supply with the correct specifications.

VEX allows teams to modify VEX parts but they don’t dictate HOW teams should modify them. My team cuts their metal components with a metal bandsaw while another team might use a Dremel tool…how is the process of charging your batteries any different provided it can be done safely?

I understand that VEX is concerned about safety and compatibility of batteries and their chargers, but I know that the “smart” chargers VEX offers are not as “intelligent” as the digital peak chargers available for a nominal price. If teams are capable of charging their batteries safely with “non-VEX” chargers, shouldn’t they be allowed to use whatever charger they want to use?

I don’t want my students to get disqualified for using our non-VEX chargers. I encourage you to re-word the rule to say something like “It is highly recommended that teams use the following chargers for charging a VEX 7.2V Battery Pack: Smart Charger, 276-1445; Smart Charger v2, 276-2519; 276-2221 (discontinued), 276-2235 (discontinued). Using other battery chargers may cause a fire or shorten the life of the VEX batteries if not used properly.”

P.S. - I gave my old VEX chargers to some new teams in our school district because they budgeted for extra batteries but didn’t purchase any extra chargers. We weren’t using them and I was soooo certain that VEX would never make a rule that governed the charging of the batteries…so now I don’t have ANY legal means to charge our batteries.

P.S.S. - Sorry for the long thread :slight_smile:

To start off, let’s requote the relevant rule. Thank you for including it in your question.

As you stated, charging batteries using non-VEX chargers is not allowed. This rule was originally implemented as part of the 2013-2014 season, and is not new for VEX Robotics Competition Skyrise.

The Game Design Committee received feedback that some teams were using 3rd party chargers to “overcharge” their batteries in an effort to gain an unfair advantage in the competition. In addition we received strong feedback from a number of teams that they don’t want us to “make them go find new chargers to stay competitive.” Other teams were concerned that some teams would “buy an advantage” through the purchase of speciality battery chargers.

Many teams are involved in the VEX Robotics Competition specifically because it is designed to be implemented without the need to find outside components to compete. These same teams provide consistent feedback to the GDC counter to those who ask us to “open things up.”

Taking all this into account, and after lengthy discussion, the Game Design Committee decided that we wanted to do something to help ensure a level playing-field for all teams regarding battery chargers.

As you may know, we try to structure the rules of the VEX Robotics Competition such that they are accessible and understandable to a wide audience, while fulfilling a variety of goals related to program sustainability. While we know there are many participants in this competition who have a strong level of expertise regarding battery chemistry and charger technology, we do not want to make that a pre-requisite for running an event or inspecting. As such we need to leave value based statements out of our rulings.

We also try to avoid putting undue burden on the event volunteers & organizers who make this competition possible. By saying “only use VEX chargers” it is simple to enforce, while making it fair for everyone.

We appreciate you providing feedback on this rule. The GDC discusses it further as we work to finalize the 2015-2016 game rules.

After that lengthy explanation, we want to emphasize the following:
There is no published leniency in this rule for the 2014-2015 season. Non-VEX chargers are illegal, and teams using them will not pass inspection per <R13e>. Teams found using illegal chargers during the course of an event will have their inspection status revoked, and must remove the illegal chargers, and re-inspect. Teams caught with an illegal charger may be disqualified for their upcoming match at the discretion of the Head Referee, as per <R22>.

While I am not posting these comments to be argumentative, I am disappointed that the response can only see one point of view to be the correct answer, regardless if it was by a “committee”, so let us revisit this issue from a different point of view.

If a team only purchased a claw-bot, the base robot kit VEX offers, would that team be competitive? Possibly at the regional level…probably not at the state level, unless they were only competing with other teams who also only purchased a claw-bot. They would simply not be competitive at the national or international level. So how is a team supposed to be competitive at each of these levels? They go to vexrobotics.com and purchase more motors, more sensors, more metal, more wires, more everything to build a competitive robot. How much would all of this cost to become competitive at each level, even if you only had one team to support? $100?..$1000? How is this not considered*** buying an advantage***?

The Game Design Committee received feedback that some teams were using 3rd party chargers to “overcharge” their batteries in an effort to gain an unfair advantage in the competition. In addition we received strong feedback from a number of teams that they don’t want us to “make them go find new chargers to stay competitive.” Other teams were concerned that some teams would “buy an advantage” through the purchase of specialty battery chargers.

The chargers I am referencing cost $50/ea. and we have one for each of our robots (3). Their whole purpose is to detect the optimum charge and then stop charging. I agree that some other chargers may not operate in the same way and some cost more, but even they cost considerably less than the thousands of dollars teams spend each year to stay competitive in the name of not buying an advantage.

*"Many teams are involved in the VEX Robotics Competition specifically because it is designed to be implemented without the need to find outside components to compete. These same teams provide consistent feedback to the GDC counter to those who ask us to “open things up.”

Taking all this into account, and after lengthy discussion, the Game Design Committee decided that we wanted to do something to help ensure a level playing-field for all teams regarding battery chargers."*

It is easy to infer that what you are saying is that your company offers an inferior product (chargers) than what is commercially available at similar prices and that it is OK to buy an advantage as long as we are getting the money.

I challenge you to disassemble any/all robots that were in the semifinal or final rounds of the national or international levels of competition. Subtract all of the parts that are included in the claw-bot kit. After this process, take all of the remaining parts and tally up the cost to participate. The company stance on not buying an advantage just cannot be supported. I would also wager that many of these teams find fasteners from 3rd party vendors that are not from VEX, so to be competitive, they have gone outside of VEX.

“We also try to avoid putting undue burden on the event volunteers & organizers who make this competition possible. By saying “only use VEX chargers” it is simple to enforce, while making it fair for everyone.”

By adding a rule that has to be enforced ***outside ***of inspection and the robot arena, organizers are now are required to enlist more staff to monitor the pits to prevent teams from breaking this rule. How exactly is this avoiding “putting undue burden on the event volunteers & organizers”?

“While we know there are many participants in this competition who have a strong level of expertise regarding battery chemistry and charger technology, we do not want to make that a pre-requisite for running an event or inspecting. As such we need to leave value based statements out of our rulings.”

Understanding battery technology is not a prerequisite for being competitive. It does, however, allow one to diagnose problems with batteries and charging systems and is a knowledge that should absolutely be used by both teachers and students. The **depth **of one’s knowledge in this case is penalized for insisting that my students use an inferior product.

In closing, I am not saying that all VEX components are inferior. On the contrary, VEX offers many products that are at a value price-point. They also create an incredible education platform for students to thrive. However, the Game Design Committee has created a rule which clearly points to not only limiting teams from purchasing products from 3rd party vendors, but also limiting them from using the best possible solutions.

P.S. - As far as the rules for 2013-14…I was dealing with a family matter last year that precluded my participation and therefore my students’ participation in the 2013-14 event. I was not aware of the rule change until this year.

The Game Design Committee appreciates your opinion and perspective on this issue. The ruling, and our response remains unchanged. As we said in our previous post, the GDC will revisit this rule as we finalize 2015-16 VRC game.

The GDC is consistently receiving feedback from the community and is always working to ensure we find the balance which best serves the balance inherent between the multiple perspectives of our competitors. Unfortunately, with a multitude of perspectives existing, there will always be someone who disappointed with a given ruling. However, we can assure you that we do take the time to evaluate and consider every point of view.