This sounds like your battery cells are badly out of balance. Suggest you forget about charging to 90% for a while. Seriously. Instead, charge FULLY, until the battery charger shuts off. Go for one of your normal rides, then charge it again, FULLY, until the charger shuts off. Do that for several cycles. My bet is you're going to see a battery that's MUCH happier, behaving as you would expect.
When you tell us that you charged to 90%, and come back later and find it at 80%, what you are seeing is very likely the result of fully charged cells charging those elsewhere within the pack with less charge. This is reinforced by the fact you rode a couple of blocks only to find the charge at 68%. Noteworthy maybe, is that my personal bike will go about 17 miles before the first of 5 bars goes out. This battery is normally charged when it gets down to about 46 volts, and that generally will happen at about 35 miles. Low voltage cut off is set for 42 volts.
You need to know that the charger is balancing the pack during that last 10% of the charge cycle - to prevent exactly what you have going on, which is reduced capacity and unevenly charged cells.....
When (if?) you get this situation resolved, then maybe re-consider this charging to 90% concept. Just keep in mind that balance charging is needed frequently - to prevent exactly what you have going on right now...... -Al
Yes, you were right. I’d charge my bike up for six hours. Went out and rode it until the battery was about 10% (One time I went a little lower even, just to try and get the higher cells down lower). Went and put it on the charger for six hours again. Did this about five or six times.
One time I even let it get down to about five but my display for the lowest setting was 42.5 so I knew it wouldn’t hurt it.
I fly electric RC and have chargers that you get to watch the voltage of the cells so I know about balancing.
I love this bike so much I can’t stop riding it. I’ve been doing about 30 miles a day (A couple of days I’ve been 50) and have almost 500 miles on my bike now. I used to have to charge up twice a day so I got the feel of the charger.
It seems with all my experience with batteries, the battery on my bike is hard to keep balanced. I need to charge it 100% before I go riding.
When I come home at night after my nighttime ride, I let it cool a little bit and then charge it up to 70 to 90% and then finish it in the morning before a ride.
Even if I still have 35% left it still takes the full six hours. I found a nice 48v charger from Vruzend that’s a 3A with a fan I am thinking about getting.
I did research and 3A won’t harm the battery. I found a four amp won’t even harm it but I’m just gonna compromise on the 48v 3A Charger for $34.99.
With all my experience with batteries, how I would not of remembered when you first get batteries they don’t work right. I’ve had this time and time again with my RC airplanes. It takes several cycles to get the battery to work right.
Thanks ahicks for the reminder. Been out of Internet for a week so I wasn’t able to check back but I wanted to post back.
One thing though, for week my green light would never go on. Ride1up sent me a new charger (then I did the 5-6) and after that it worked so it could be the charger.