I am newbie rider, with an MSP HT, I rode one of Marty’s Mt. baldy tour. I started with 100% battery, after about 23 miles up the Mt. Baldy lodge, I had 50% left on my battery, so after coming down I end up with 36% battery. I would say I use less energy because of regeneration but I could not say you would gain more than what you have when you started going downhill.