Why won't my new battery power my MacBook?

I recently inherited a MacBook Pro from a family member. Before gifting it to me the hard drive and battery were replaced. The battery has worked fine for about 50 cycles

Now if the computer is unplugged it immediately dies. When the charger is plugged in it only glows green (never amber). The battery reads 100% charge but is listed as "Replace Now" under the condition. No liquid spills

Here is what I have tried:

1. I inspected the battery and its attachment and everything visually looked ok. I unplugged the battery and plugged it back in
2. I reset the PRAM
3. I reset the SMC

Here is what my battery data states:

• Charge remaining (mAh): 6437
• Fully Charged: Yes
• Charging: No
• Full Charge Capacity (mAh): 6437

Health Information:

• Cycle Count: 51
• Condition: Replace Now
• Battery Installed: Yes
• Amperage (mA): 0
• Voltage (mV): 6002

Let me know if you can help before I try a computer repair shop. Thank you!!