One thing to keep in mind. All 48v batteries aren't even. Ask the manufacturer what is the top voltage and the cutoff voltage.

I had a Ping Battery Lipo4 that was called a 48v but charged up to 59v
This is comparable to the Luna Cycle 52v battery.

The 48v I bought from Calibike was reasonably priced but only goes up to 54v. I get around 2-3 miles less top speed then the Ping and it's more sluggish on hills.

Good luck.