Inspiron B130 battery and charging issues

Own a 5-yr-old Inspiron B130. Recently replaced the battery, which was a 4-cell, 29WH, Li-ion with a new 6-cell, 5200mAh, Li-ion. Figured I go with a 6-cell this time and hope to get more battery time. So far, I've tried 2 different batteries and ended up shipping the first one back as suspect. Neither 6-cell battery would charge past 94% no matter how long I left it on the AC Adapter, which is a 60W PA-16 type. (BTW, the old 4-cell still charges to 100% just doesn't last very long, and we get the following error message: "Your battery is able to charge normally, however it is reaching the end of its usable life.")

I did some Li-ion battery research, and according to http://en.wikipedia.org/wiki/Li-ion_battery laptop batteries should be charge at 80% their rated mAh. So, the 4-cell requires a charger that outputs 1.57A and the 6-cell requires a charger that outputs 4.16A. My 60W PA-16 type only outputs 3.16A, so I figure 60W isn't enough to charge the 6-cell battery. So, I tried a 90W charger (which outputs 4.62A), and although it was better it only got to 99% and BIOS (running the latest A10 version) doesn't recognize it as a 90W charger.

So, what am I doing wrong? Can I not use/charge a 6-cell battery in a B130? Why didn't the 90W charger fix my problem?

Thanks is advance for any help!