Ah. You have Mike D's original basic charger design. Good.
http://99mpg.com/Data/Resources/down...dchargerv1.pdf
If you're in cold weather, I'd dial it up to 182V and try again. If your pack voltage is under your set voltage, there's no possible reason for it to stop charging. You may have a voltage measurement error somewhere where you measure the set voltage to be higher than it is. You may also have a defective power supply or maybe there's insufficient current flowing through the power LED
A simple way to confirm current flow is to set your DVM to 10A ammeter mode and put it in series with the leads. It should show you 0.35±.01A if you're actually charging.
A couple things to try:
If it's cold weather, charge it for 8 hours provided you never see more than a 3V dip from the max. See if there's an improvement.
If you put suction on the fan exhaust in the trunk, you can get air to circulate through the battery.
Good luck,
Steve