Bluetooth and impact on battery

[kristalsoldier]

Hello,

I just found an old though yet unopened portable Bluetooth KB...originally it came with my Palm Treo. Assuming the KB works, does extensive use of BT drain the battery? And can I use two BT devices at the same time - the KB and maybe a set of headphones?

Thanks

EDIT:Forgot to add that I will be pairing this with my A500 tab. Thanks