When you connect two lithium-ion batteries with a voltage rating of 3.7 volts each in series, you effectively double the total voltage while keeping the overall capacity unchanged. This series connection is often used to create a higher voltage power source for specific applications. Here's how it works: Voltage Increase: Each lithium-ion battery has a nominal voltage of 3.7 volts. When you connect them in series, the voltages add up. So, in this case, 3.7 volts + 3.7 volts equals a total of 7.4 volts. This higher voltage can be useful for devices or applications that require a greater power supply than what a single 3.7-volt battery can provide.

3.7 is the nominal voltage per cell. 8.4V is the charged voltage for a 2S lithium ion battery. Discharging a lithium ion battery below 3.4 per cell will destroy it. And, the battery you tested was below 50% capacity. Sounds like you shouldn't be the one explaining this to other people. @@oWONTEKo

Did you actually watch the video? these are 7.4 volt/3700mWh batteries, absolutely a rip off. Sounds like you're a reseller trying to cover up the scam.

@@oWONTEKo 3.7V is nominal voltage of each cell.. So nominal voltaje of the batery is 7.4V, fully charged do not reach more than 8.4V.. This is for all brand Li-ion 6F22 bateries, not only EBL

​@@desousafrancisco not 9 volts.