Pretty sure my kit included a 13ah battery but its been on the bike coming up 2 trouble free years - had an initial hic-cup with the pas sensor sorted with an email to support and a brief exchange - not the best support but not the worst either.
The pas/speed control was a bit of a hurdle to get accustomed to ( full power upto 8mph - pas1 full power upto 10 mph pas2... ) and i ordered the forum recommended controller upgrade and never fitted as i got used to the system after a week or so.
The Yose kit works and so far the battery is as good as it was..
While i live upslope from most locations there are few big hills near here but the motor hauls almost 100kg of me up all of them that i have encountered, though the steepest was a challenge to maintain 8mph closing in on the crown.
If you have major hills to climb perhaps a system with a 48v battery/system would suit better. Otherwise Thumbs Up..
Just ensure your crank axle is 17mm or less in diameter if you opt for the default pas sensor option, if a tad bigger than 17mm you could have the same issue i had others performed a successful mod/hack to the sensor I didnt and i bought a 2nd chainring side option sensor instead.
EDIT-Additional info - my use of the e-power is regular but light, i ride out without power mostly (down slope) generally using power only when tired or returning, weekly Millage? - low? I charge the battery once a week-10 days when needed.. and the KT controller ended up on my 2nd ebike - the number of ebikes NEEDED = the number owned +1 to paraphrase someone in here..