Batteries for high score saves on pcb's: Tetris Plus 1 &

[D]

These pcb's should be able to save high scores if a new battery is inserted right?
I just bought new batteries. Put them in, save a high score,
power off,
power back on, poof! gone are my high scores.
So this happens with my Jaleco Mega System 32 Tetris plus 1
And with my one board Tetris plus 2.
What's up? anybody know?