Lipo issues

[Yoldume]

just took my buggy out and all was well for about a minute until all the power went and it was coasting around as if i was running a flat nimh pack,

so i walked home and plugged it into my charger and it read 7.96v my charger takes it to 8.4v (is this correct ?) so if it was nearly fully charged whats gone wrong ?

and tbh i think my charger is innacurate because when i fit my lipo monitor readout to it it mainly reads a different of -0.6 to what the charger is telling me

and i also think my lipo cut off in my esc is turd it cuts off at 3.0v per cell and ive checked it after a run and s1 was 3.19v ans s2 was 3.23v

also when i balance theres useually a +/- OF 0.4v

is this all normal or could this be why my pack is acting funny ?

cheers