Hybrid battery network for implantable medical device

A long-life high speed battery network comprising:

• a first battery having an anode and a cathode;
• a second battery having an anode and a cathode and electrically connected in parallel to the first battery;
• the anodes of the batteries being directly connected to each other, and the cathodes of the batteries being directly connected to each other;
• the first battery having a higher resistance and higher open cell voltage than the second battery;
• and
• the second battery having a greater current carrying capability than the first battery.

An implantable defibrillator comprising:

• a battery set comprising first and second batteries each having an anode and a cathode, the first and second batteries connected in series with the anode of one of the first and second batteries connected directly to the cathode of the other of the first and second batteries;
• a third battery electrically connected in parallel to the battery set;
• the battery set having a higher open circuit voltage and higher resistance and a greater energy density than the third battery;
• and
• a charging circuit connected to the batteries.