E900 life battery terrible short !need help

Firstly , i would like to thank you for your help . I bought an used e900 from ebay last week and it works fine and is in very good condition. The only problem i was aware of was the short life of the battery so i provided to buy two new one ( 1 normal litio 700 amph , 1 litio polymere 1500amh).

Actually, that 's was useless. Even though i charge it over 16 hours , the mobile doesn t last more of 3 hours in stand by mode.

I tried to flash up the firmware , right now i have the xxfj2 version (no relevant difference from the other one)

i turned off the bluetooth.

i turned off the edge function and set it up manual.

Network research is set to manual (my provider , wind , italian)

i even tried to reset it with the code to the original settings.

All these actions didn t give me any benefits. So i suppose there is something wrong with the bt module wich discharge the battery maybe?

I sent a mail to samsung and they told me i might probabily need to update the software. if they meant the firmware i had already done it.

i really appreciate your help.

thank you