Bad battery? on 1993 Nissan Altima

Cleaned battery terminals, charged battery, changed spark plugs, checked all connection's and fluid levels and engine just wont kick over. It try's to, but just wont fire up. I'm wondering if the battery may be bad. When charging it, it's suppose to go to 0 when it's finished charging, but will only go to 7. Is there something else I should be looking at.

2 answers 2 comments
How old is the battery? If it's more than 4 yrs old you have a bad battery.
The battery is only a year old (Interstate)
If the batery is 1yr old. It's covered under a total free replacement within 2yrs. Call the 800# on the battery and take it to a shop that sells them.
Love my Nissan 2008 Altima....but have had to replace battery every 18 months since I've owned it. Have 3 close friends also with Altimas....same problem with each of them. So, pretty much, I now just automatically replace the battery to avoid issues. There is never a warning...it just goes, and I do get the battery checked at each service call.