Battery shifting and causing power loss at start-up

[Lola Run]

Hello,
I have a 2000 trail blazer, just passed 200,000km. My problem is that it seems that my Canadian Tire Eliminator battery is shifting and causing my well-tightened and clean battery cables to shift and essentially; loose connection. This often happens at start-up, lately, more so in the cold (mornings). Usually just as I turn the ignition, there is a click, and no power. I then have to open the hood and either that does it, or I have to slightly wiggle the batter cables. Interesting...
I have noticed previously that, when stopped at traffic light, my electronic odometer is slightly pulsating in tune to the engine.
As well, when driving down hill on my country driveway, sometimes my car will stall. This only happens shortly after start-up, not during subsequent starts (same with the above).
Any ideas?
Thank you, everyone!

[mrfirebird]

sometimes the cables carode on the inside of the casing ,might take alook at that.

[BlazerLT]

Clean your cables and retighten them.

Also, your battery should be held in place with a clamp at the bottom of the battery.