Finding the right child seat or the right bicycle seat for your electric bike can be a bit of a puzzle. You think there's a battery in the way. Fortunately, there are several solutions to finding the right bike seat. It is not as complicated as you might think to get a bicycle seat on your electric bike.
For you with a self-installed battery
If you have a battery mounted on the package holder, it is easier to drive just a package holder attached child seat. A package holder that has a battery room is usually taller than a regular package holder. A frame-mounted child seat then often has too short braces to end up above the package holder in a good way. Make sure that the bicycle seat has a bracket wide enough to handle an electric bicycle package holder.
Mount correctly and do not drive with a too heavy a load
Most chairs today can handle a maximum weight of 45 pounds, with the weight of the child's seat included. Driving with a child who exceeds this weight limit always entails a risk of material defects and accidents. Be sure to mount with the right tools, check that everything is connected as it should be. That the child seat clicks into its possible frame bracket and that everything feels solid and stable.
For you with a frame-mounted battery
A battery mounted on the lower tube of the frame usually does not affect the choice of a child seat. Having a package holder on the bike helps in attaching a bicycle seat to it. Frame-fastened child seats also fit perfectly, as the bike's seat posts look the same as on a regular bicycle.
Good luck with the electric bike with your child!