As a general rule, services by themselves are unrelated to battery life. All a service is at this level, is a way for an application to tell the system "hey I'd like my process to be kept around if you can." If your process isn't doing anything, then it isn't going to use any battery, just sit there in RAM. It's what it does while being there that matters -- doing networking, holding wake locks, running the CPU, etc.
Also the sitting there in RAM can however build up to have an impact on battery life. If one application has one service running, then you use a little RAM and maybe can only keep 5 instead of 6 processes around in the background. However, if 10 applications are all insisting that they need to stay running, then you can get to the point where you can't keep any background processes around so the system has to do more work as other things are happening, bringing up application processes more often when before it could re-use one it had recently launched.
Worse, if so many applications insist they need to be running that there isn't enough RAM to keep just all of them around, then the system will start thrashing as it evicts services to run other services and starts cycling through them. There are
mechanisms to avoid this spiraling out of control (as it sees that not everything can be kept running it will throttle down how much it tries to keep running at once), but it's definitely not a good situation to be in and will negatively impact the battery life of the device.
A quick way to tell how you are doing on RAM is to go to Running Services and see how much "free" RAM it shows there. This is actually the RAM it has available for background/cached processes -- under normal circumstances we'd like to have enough RAM to keep say 5 or so moderately sizes cached processes around. For things to stay in good shape when running heavy-weight applications like the web browser it is nice to have say 100MB free RAM available when viewing this from settings.