The jailbreak itself doesnt cause any battery drainage.
Open sbsettings and check your processes.
Is your brightness all the way up?
Are you using the phone or is the screen off?
You're getting over 16 hours of battery life which isnt really bad at all I don't think

brightness halfway
i did a test and left it on standy and came back to it every 5 or so mins..used phone for 3 mins ,put on standby for 5/6 mins, used phone for 3 mins....

maybe the battery is depleting normally, i've only just decided to display the % indicator so am noticing it depleting more.. you don't notice it that much when you're just displaying the battery icon....

if you're really surfing the web that's pretty normal.
consider this: estimated battery on wifi is 9hrs, on 3g it's 5hrs.
that means that on wifi, the phone drops 11% per hour, on 3g it drops 20% per hour.

BUT: I have a problem with my 3gs where the battery just drops for no apparent reason. it's seriously annyoing. maybe you have the same thing ...

Mine looses battery aswell, about 3% overnight while in standy, while surfing about 3% every 10 minutes, gaming takes a whole lot more battery.
I`d really like to know why it`s draining the battery overnight while it`s in standby, no processes are running.

Mine looses battery aswell, about 3% overnight while in standy, while surfing about 3% every 10 minutes, gaming takes a whole lot more battery.
I`d really like to know why it`s draining the battery overnight while it`s in standby, no processes are running.

3% overnight is completly normal. in fact, that's pretty good. standby time is 300hrs. that means that in 9hrs ("overnight") you loose 3%.

oh and btw: there are ALWAYS processes running on the iphone (numerous in fact, at least 20 even in standby).

I know there are processes running that sbsettings doesn`t show, i was talking about processes like : safari, ipod and such.
As for battery draining overnight, my 3G doesn`t loose battery overnight at all...

I know there are processes running that sbsettings doesn`t show, i was talking about processes like : safari, ipod and such.
As for battery draining overnight, my 3G doesn`t loose battery overnight at all...

well it's likely that it just doesn't show that, it's not always accurate. as I said, the advertised standby time is 300hrs, so 3% in 10hrs in standby is normal. if your 3G doesn't do that, that's cool, but it's still totally normal.