Or should i take it out? and just stick it back in when it needs charged

the charger gets a little warm and it worries me a bit
a
nd I'm afraid it may hurt the batteries

You can, but it's not good for the battery.
I would suggest only charging it periodically.  If you wait until it needs to be recharged you may need it before it is ready.  I would only charge it once a week or anytime it's seem a siginificant amount of use.  YMMV.

I own a Magcharger, a Stinger, a  Streamlight LITEBOX too.  I only charge them when I think or know they need it.

The are not LI-ion and can be left in the charger all the time. I get 4 to 5 years out of mine.

Leave it on the charger at all times. The charger is a smart charger and will not over charge the battery.  I have never had a problem with a Stinger and I had one for 11 years.  I did learn that heat from the car and extream cold temps are bad for it.

I have three Stingers and several AC and DC chargers.  The batteries go bad about every year.  There are places that make replacement batteries cheaper than Streamlight.

Being in the electronic field, I can say the voltage regulator transistor inside the cradle has NO heatsink on it and it runs hot.  Hot enough to scorch the circuit board.  I had one charger fail due to overheating. Heat and electronics are not a good thing.  I could look at the device rating and measure the temp with an IR thermometer, but I know it shouldn't get that hot.

It may not overcharge the battery, but I no longer leave them plugged into the wall.  I have still had batteries go bad in a year, so that is probably unrelated.

I plan to drill additional ventilation holes in the charger housings for additional passive cooling.  There are no vents in the housing, IIRC.

The charger gets warm when the light isn't in the cradle too.

Quoted: The are not LI-ion and can be left in the charger all the time. I get 4 to 5 years out of mine.

How long does that charge take?

My bats usually last about 3 years in my Stinger.

Quoted: I have three Stingers and several AC and DC chargers.  The batteries go bad about every year.  There are places that make replacement batteries cheaper than Streamlight. Being in the electronic field, I can say the voltage regulator transistor inside the cradle has NO heatsink on it and it runs hot.  Hot enough to scorch the circuit board.  I had one charger fail due to overheating. Heat and electronics are not a good thing.  I could look at the device rating and measure the temp with an IR thermometer, but I know it shouldn't get that hot. It may not overcharge the battery, but I no longer leave them plugged into the wall.  I have still had batteries go bad in a year, so that is probably unrelated. I plan to drill additional ventilation holes in the charger housings for additional passive cooling.  There are no vents in the housing, IIRC. The charger gets warm when the light isn't in the cradle too.

I like the Stinger lights but in my experience, the batteries are junk.  They just don't last.  I was in the police academy and a lot of guys had the Stingers.  At least half of them had the batteries fail with much less than a years use.  At the PD where I work, the Stingers are the most common belt light.  Again, about half the officers in my PD have had to replace their batteries more frequently than once a year.  

The Stingers are great lights but Streamlight can't seem to make consistenly good rechargeable batteries.

I've been using streamlights for duty use since I started back in 1998.  The battery sticks lasts me about 2 years before they start crapping out.  I wish they only lasted less than a year because the sticks ahve a 1 year warranty and then I could continously get free battery sticks.  

I own two stingers. I keep one in the charger and one on my duty belt. I change out when they die. Leaving it in the charger doesn't hurt anything. I've had these two flashlights for 11 and 9 years. It will be fine!!