Macbook pre-unibody battery cycle

After reading up on battery cycle counts i did a little check of my battery's health. I found a count of 1089, but it seems to be in good health. I have just got a new macbook but am giving the old one to my son for his school work. Do you think it would be advisable to have the battery replaced or should it be ok for a while yet?

If it aint broke don't fix it.

If you are still getting decent working times off the battery, then keep it in.

ok thanks!