Need help with new battery and possibly controller

I bought this a couple years ago (also in my sig)
https://bmsbattery.com/ebike-battery...r-battery.html

and it's powering Hub Q100h w/S-LCD3. The battery lasted less than 6 months. Life kind of got in the way and basically that pack is trash now. I want to replace the battery, I believe this is what I want

https://lunacycle.com/batteries/pack...3-5ah-dolphin/


but have a couple questions.
1. Is it safe to use with the charger I have from original setup?
2. My 20A controller is integrated in to the frame mount, I believe that can be re-used correct? If so any reason not too? Any worthwhile upgrades I should consider?
3. Is there anything else I should take in to consideration installing this new battery?

The link to Luna Cycle doesn't work, so we don't know exactly which pack you are looking at. But if it is a 48 Volt unit, the answers to your questions are;
1)Yes
2)Yes
3)No

Awesome thanks...yes it's a 48V unit