48v 13ah lithium battery powering small scramble bike

I am building a small electric "scramble " bike for my young son that altogether including him would weigh far less( about(180lbs) than an e-bike carrying an average weight adult ( about 220-240 lbs) . I want to power it with a lithium battery that is 48v 13ah which will be running a 48v 800w electric motor. I do not want the bike to go at great speed maybe about 30 kmh mainly over grass etc and I have a couple of questions please.
Will the battery give a good power to the motor and a good "take off" from start taking into consideration the weights mentioned above.
Also what sort of time would this battery last before it needs charging again. I know it cant be exact but some idea would be great.
Thanks in advance

Really hard to say, since a lot more variables than weight and battery capacity goes into the calculation. Slope plus weight matters a lot. So does wheel size. But it should not be an uncontrollable amount of power at that weight. It will be a handful for a very young child, so expect some crashing if he's that young. There are ways to tone it down to 400w if you need to start lighter.

Your battery should easily put out 1000w continuous, but with some noticeable sag in voltage under load. More voltage drop as well, as it gets used up. So it will be very perky at first, then less so as you lose voltage near the end of the ride.


To paraphrase the forged in fire show ( it will cut) , It will be fun. Should be fun for about an hour, but really hard riding could use it up sooner.