what kind of batteries are these?
Judging by the 3.7v voltage, it sounds like they could be Polymer Lithium Ion batteries, which are 3.7v output. (the flat ones, like these: **broken link removed** )
if they are, you should stop trying to charge them with such simple methods... they require specialized chargers and you'll probably end up destroying them if you continue.
also, if you measured ZERO volts after charging, it sounds like you may have damaged the batteries already, no matter what type they are...
If they aren't that type, well then disregard this message.