Once you ride for awhile you'll get a sense for how hard you can lean on the battery depending on the length of your ride.
BTW, spare full sized batteries are really expensive. Shimano is $700, Bosch is $900. I'm sure that Yamaha is similar. The batteries actually have a lot of electronics built in, they aren't like a car battery.
If the regular, high capacity battery gets you "out there", where you run out of juice, I'm not sure what the cheaper, lower capacity battery is gonna do for ya in getting back under battery power.
The trick is to ride the bike and get a feel for real mileage numbers in each Power setting, so there will be no surprises.
As poster Honkinunit said, mainstream batteries are a considerable investment. And there are no mainstream manufacturer's batteries out there that are low in capacity. And because of that, you would be paying near a grand for a 500wh battery in those brands. 475 seems quite low, and I do question the watt hours of that battery and how far it's gonna get you away from homebase. Good luck and keep us posted as to what you do.
Not a bad looking bike. And $475 for an extra 778wh battery seems to be a nice deal. I'd be tempted to go with the extra battery. Impressive Bafang motor specs, too (160nm of power). Definitely looking !forward to reading your ride reports and overall impressions
That bike should ride very decent without power. Another battery might be good if you plan on any long trips where you want to cover a lot of distance in one day or go places where charging points are far apart. $475 is a very good price depending on battery technology.
I ride a lot of areas with loops and shortcuts and not always linear so if my battery dies even one with less capacity could get me back. New to these and just running ideas out here among the experienced eMTB riders.
I own a biktrix Ultra 1000 EBike it’s the hard tail version of the red bike above. FYI these are built by Frey bikes in China the batteries are called Dorado battery I own a 48-52 v 21 ah battery as my main battery but also have a 48v 11 ah battery for a backup. It’s a great system the cells are panisonic or LG 21650 cells the 11ah battery is about 7lbs where the big 21ah battery is about 11lbs these run from 300$ for 11ah to 900$ for the big 21 ah battery so having a backup that is lighter weight is definitely affordable. The nice thing about having a spare battery besides the obvious is to troubleshoot your system if you are having issues. I highly recommend it.
778 wh is a lot of juice I have a 680, and that gets me about 50 miles of commuting with a bbs02 (52v battery). I run my pas from 5 to 9 pushing for speed to get home fast. I also run a 52 up front so I can ride at 30-35 in roads. Face about 1700 of vertical in my 45 my commute. If your can get a general shark battery. Em3ev has a great bms with an Android app that lets you see exactly how your battery is doing.