Quote:
Originally Posted by adey
That's a very insightful evaluation. I am going to pass this on to my mate who had the dumping issue in response to the argument that a 3200 mah low profile lipo cannot sustain a 13.5t motor in blinky for a 5 min run. Thanks
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Cheers.
To comment on your racing buddy's situation with 3200mAh packs, I'd suggest the packs may just be experiencing a voltage drop under load. This may be triggering the low voltage cut off on the speedo, and so if looks like the packs dumped. Has he disabled low voltage cut off on the sppedo? If not, do this.
At this point we don't know the age or condition or numbers of charge/discharge cycles of those packs. I suspect they aren't new.
If you assume 1665-1700mAh (that I was pulling in 5 mins) from a 3200 pack, you are using over half the capacity. If those packs were LiHV (and not Lipo), then they wont be charged to 3200mAh anyway, so indeed he would be puling far more more than half of the capacity out of the pack. A pack under load will experience voltage drop.
I think the current draw (and therefore voltage drop) profile from a modified motor will be significantly different to that of a stock motor. Mod will likely be lots more spikes as you are on and off the throttle more, whereas stock will be more constant. Modified motors will potentially draw higher current for less time, with stock motors pulling a more constant load. The output capability of the pack will therefore be felt more in stock racing, where as its may not be as noticeable in mod.
Take home message is: buy a new battery...
