Anonymous
You can easily and quite cheaply build your own li-ion battery packs with very little knowledge and overhead to get started. I’ve built a few for my e-bike and they beat lead acid batteries hands down on every level.
Here’s a good tutorial and it’s very easily to scale, but better to hook your needs up into blocks, rather than into a single system. A good place to start is to get a power consumption meter and see what you need. Here’s a source: https://energyusecalculator.com/electricity_usage_monitor.htm
And here’s a resource for building li-ion battery packs.
How To Build A DIY Electric Bicycle Lithium Battery From 18650 Cells