You're putting a lot of faith in the battery and charger flying blind like that. It's not very expensive to purchase a loaded meter. Think of it as saving $150 woth of plane.

The wall charger works perfectly well. It's a matter of opinion but the wall charger might be better for the battery than a quick field charger.

Get you one of these: You and your buddy can share it for $10
http://www3.towerhobbies.com/cgi-bin...?&I=LXNK82&P=7

or put one of these on your plane so you know at a glance: $12
http://www3.towerhobbies.com/cgi-bin...&I=LXHDJ2&P=ML

You can buld a battery discharger for less than $5 from a 12V automotive bulb. That'll let you cycle your batteries.
Or you can get a Triton Jr (or similar unit) and it'll run a cyle automatically. http://www3.towerhobbies.com/cgi-bin...&I=LXMAH9&P=ML

It's so cheap to all but prevent this from ever happening again. For $10 you can protect your plane unless the battery faults in-flight (not very often).

Have fun!