Slow crank

Hey guys a glimmer of hope!!!! Well that or maybe you guys can give a little insight. I get off work too late to buy new voltmeter until Friday. However had battery on trickle charge all day got home went out and car cranked over nice and fast and popped to life for a brief moment! However after a couple minutes trying of cranking both battery cables were hot! Then battery got week. If that helps explain the battle? Battery is a CCA 850
The cables get hot due to resistance. As the cables get hot the resistance increases.
Either the cables are too small or there is a loose connection. Since it is both cables sounds like the cables are too small. What gauge cables did you use and how are the terminals fixed to the cables?