I just bought a Colco thunderbird and lost the instructions. I need to know how long it takes to charge the battery pack (nimh 700mah).

It says on the charger:

AC/DC ADAPTOR
MODEL:XDC 4120-129
INPUT:230V~50Hz
__
OUTPUT:12V---350mA

(-)---(O---(+)

Also due to Chinese reliability am I right to suspect that this is a 50mA charger and will this charger charge my JR TX?

LOL!!

Ok.. first; that beast of a charger will toast yer JR Tx.. I think.

Looks to me like JR's 'reverse' polarity charge port (center pin negative) and that chinese animal's center pin positive plug may cause you to change your name to 'sparky, the desert-rat.'. Use the wall wart that came with the JR Tx to charge the JR Tx.

Next.. I have no clue what the cell count on the 700ma motor pack is.. assuming it's a 6 cell and assuming the creek don't rise, I'd start watching the pack closely at 30 minutes of charge.. I suspect that's about a one hour 'Fast' charger (or less). When the pack gets warm stop charging and look at the clock; and never let it charge that pack unattended as I suspect it's an un-regulated 'fast' or 'quick' charger.

Good luck!

Hope this helps!