Transponders for PPIR

[Scored51]

Hello Everyone,

I intend to have the transponder system up and running for Friday's practice. Times will be posted throughout the day after each "round" is completed. If you intend to use your transponder, please make sure to schedule the charging of your transponder such that it finishes charging Friday morning before you need to use it. For example: ready at 9:00am Friday - approx. 15 hours for charging = 6:00 pm Thursday start charging. This will provide the best chance of it lasting for the entire weekend, but remember to bring your charging kits just in case you need them.

Transponders will be available for rent when the race day office opens Saturday morning.

If you are borrowing a transponder for the weekend, please email me at c.dale@comcast.net with your name and competition number along with the racer's name and competition number from whom you are borrowing. If you have recently purchased a transponder, you can send me an email with your name, competition number, and serial number of the transponder, or you will need to see me at the track in order to have it registered in the system.

Thanks,

[Scored51]

Updated above for race day office hours.

[phildrummond]

newbie question- can they be OVERcharged? I travel a bunch and wondered if my house would be charred ruins if I left it charging while I'm gone. I usually hook it up the second I get to a Pueblo hotel the night before the race, giving it maybe 12 hours of charge.

Seems the short charge makes it show slow lap times, though...yeah, that must be it.

[Scored51]

Yes, they can be overcharged and ruined. The transponder is powered by a NiMH battery that works by the same principles as the rechargeable ones you can buy at RadioShack.

The risk of starting a fire with your transponder is higher than with other rechargeables because the battery has no good way of venting the heat produced by the charging process. This is also why it takes an average of 14 hours to charge these things instead of twenty minutes. I've found that no matter how many amps you have available (in order to charge it faster) it will still only draw the electricity it needs to charge at a slow pace. However, before the sale of the transponders I was regularly charging nearly 200 units at once without any issues. That being said, the electronics of the transponder are obviously limiting the rate of charge. A failure of these safe guards could create an "unexpected thermal event".

[phildrummond]

An unexpected thermal event sounds kind of cool! Thanks for the info. I suspected you could burn them up charging too long, but I was never sure what too long is. I usually charge until I get 3 blinks from the green light.

[rybo]

Tom,

The green light will go solid when the unit is fully charged.

Scott