Quote:
Originally Posted by zoaman
so why not make the rule.Anytime a lipo battery is connected to a charging unit it must be in a sealed fire proof containment. this will eliminate charging, discharging or even checking volts amps checking.easy to police then.
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Because I could equally discharge the cell on a resistor... which is not a charger... We thought of that!
We don't want it in a sealed container as the LiPo fire involves rapidly expanding gasses. That expansion would pressurise the container which would eventually either explode, or require disposal as a pressurised container. If you relieve the pressure the noxious fumes escape... see below.
We don't want it in a LiPo locker because we can't access the LiPo with sand to extinguish it. The locker relives the pressure by releasing all the noxious gasses into the atmosphere, and without access for the sand to extinguish it, this goes on for many minutes. In a confined hall that would mean evacuation and then measuring the fume levels before we go back in.
In our classes we usually have less than ten seconds covering every ten drivers. When the battery performs better (see post above about flying in the cold) it can shave 0.2s off a lap. Multiply that by the 35-ish laps we do in eight minutes and we have a time improvement of seven seconds, or getting into the higher final.
In sorting this out with the EB and the Exec, we are talking about a handful of people who do this. It isn't widespread, and it isn't something the top ten drivers have done at the two meetings I have checked.
Honestly, it is something the middle order drivers do because they think the top drivers are doing it and they have to do it to keep up. As someone said on this thread or the other one, a few missed apexes and the advantage vanishes.
One thing I can tell you does work. If you are using LiPos in the controlled blinky classes and getting a lot of low-value discharges, then discharging the LiPo to 3.6v and charging it does improve the performance. I do it once after every meeting with each cell at about 1.5C and it works. At the meeting I use the cell without discharge and charge at about 1C or less.