Quote:
Originally Posted by Drifted Demon
I have a Premium Power 4700 20C 7.4v lipo. Ive noticed in the past couple of months, it reaches cut-off, 6v, too soon i believe. When i chuck it on the charger & check its voltage, its not even under 7v, 7.5v is the lowest ive seen it. Im using a mm with vortex 7.5 motor, fan on both motor & esc, TT01 geared mid 7 fdr
I believe under load, its hitting cut-off, voltage spike, or amp rating of pack is not strong enough? Ive also noticed lately the pack is coming off from a run warmer & warmer. I thought it might have been the plugs so i changed them to TRX but problem/issue still persists. Im thinking of buying a higher C rated, higher capacity pack, If you guys know what the problem might be, any info would be great
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Any battery will measure higher voltage when not loaded at all, but 7.5v is a bit higher "floating" voltage than normal after tripping the LVC. Typically, a floating voltage of ~3.5v/cell is more common. That tells me that the setup is drawing more current than the pack is really capable of and the voltage is dropping too far under the load, which sets off your LVC.
FYI; the connectors themselves would get warm if old/worn because that would be where the voltage loss would occur.
Loss of apparent capacity over time and increasingly warmer cells after a run points to the cells degrading and their internal resistance increasing. Chances are those cells were just
barely adequate when new, and now that they've seen a number of cycles, they aren't up to snuff at all. If/when you do get new cells, shoot for a little higher quality, or something with a higher C rate and/or capacity.