Given DKNguyen's answer to my last question, I wanted to know what determines the internal resistance of a LiPo battery. Does it have something to do with its inside chemistry? Is it just roughly calculated by the manufacturer via testing?
-
\$\begingroup\$ the internal resistance is determined by the chemistry and by the construction of the battery ..... it is unknown how any manufacturer calculates the internal resistance of the battery \$\endgroup\$– jsotolaJun 3, 2019 at 18:17
-
\$\begingroup\$ @jsotola edited \$\endgroup\$– Iaka NoeJun 3, 2019 at 18:59
-
\$\begingroup\$ think about what you are asking ... the last question is not related to your main question in the title ... it also makes no sense really \$\endgroup\$– jsotolaJun 3, 2019 at 22:31
-
\$\begingroup\$ What are you talking about? I'm asking why the number that appears in a battery's datasheet as internal resistance is what it is and what would change that \$\endgroup\$– Iaka NoeJun 3, 2019 at 22:44
-
\$\begingroup\$ sorry for the misunderstanding ... your last question makes it sound like the manufacturer sets the internal resistance somehow ... if you original post was similar to you comment, then it would have been more clear \$\endgroup\$– jsotolaJun 3, 2019 at 23:33
1 Answer
Internal resistance is dependent on a number of factors, including:-
- electrode and separator thickness
- porosity of electrodes and separator
- active material particle size and type
- electrolyte chemistry
- interconnects
A lower internal resistance is desirable for improving the maximum discharge rate, as it reduces internal voltage drop and heating. Most lipos use similar chemistry, but high power cells need thicker plates with larger interconnects to lower the metallic resistance and avoid 'hot spots'. This makes the cell larger and heavier than one which is optimized for capacity.