Think it will prob have to be battery will be just for horses and the length will 50 metres and another run of 40 metres. Which is the best way of powering it solar or battery? thank you!#
If you google 'starter electric fence kit for horses', you will see other options too.
I don't know anything about solar powered energisers, sorry, but they sound like a good idea. Replacing any dry battery with a leisure battery or old car battery will save you money in the long run (the dry batteries are expensive and don't last for long).