Use this EC3 Series Harness for connecting two identical Lipo batteries in series.
When connecting batteries in series, you add the voltage of the batteries together, but the capacity remains the same.
For example, if you connect two 11.1v 2200 mah 30C (66 amp) Lipo batteries together with this harness, you end up with a 22.2v 2200 mah 30C (66 amp) battery. This is a great way to make use of your smaller Lipos in large models, saving the cost of purchasing large capacity Lipos that can only be used in large models.
The wire on this EC3 Series Harness is 14 gauge with silicon covering for very good flexibility. It has one female EC3 connectorand two male EC3 connectors.