V180 new battery life ??

I have a V180 whose battery charge drops from fully charged 6 to 2 in
less than one day with maybe 12 minutes of talk time. So...I got a
brand new replacement Motorola battery, popped it in today...battery
meter only gave me a 4, which is what it registered with the old one.
Do I have to charge a new battery? I expected to see a 6 with a brand
new battery.

This is a work furnished cell phone. Other users of the same phone
report long battery life, but not me. Any clues?

Thanks.