I bought a plane that had a 4.8V 600 mah RX battery i removed this battery because it was sitting for a few years. I replaced it with a 6.0V 2500 mah battery would this cause any problems with servos? These are the servos http://www.horizonhobby.com/products/JRPS537#t6

Depends on two things. They type of receiver you have in the plane and the type of servos. Most receivers can handle a fully charged 6 volt pack however some servos cannot ....even some new servos cannot handle 6 volts. Typically what will happen is the servo(s) will start to jitter. Sometimes the jittering stops after the battery settles down to around or just below 6 volts.......sometimes they don't stop jittering.

Edit:
Just saw you added the servo model. One set of specs show only 4.8 v yet another show both 4.8 and 6.0 volts. I just had to remove some new JR/Spektrum servos A6060 as they about jittered apart on 6 volts even though their specs from Spektrum state they will work on 4.8 or 6v. After calling Horizon they fessed up that the servos are 4.8 volt only.
You won't burn them up by trying but I would watch them closely to see if the twitch.

See these entries on the specs page:
Thats your indicator that the servo will be fine on 5 cell or 2s LiFe(A123) packs

What Barracuda said is right on the money. You will be just fine with that battery pack and those servos.<div>
</div><div>Ken</div>

These are the servos http://www.horizonhobby.com/products/JRPS537#t6 and i have a Spektrum AR800 RX.

From every thing I have read on equipment you have stated you are good To Go

cheers Bob T

p3arljam :

The servo specs from the web page you linked to clearly states 4.8 - 6 volts. Sooo... your good.

Most if not all Specktrum receivers are good for something like 9.6volts.