eCue wrote: ↑
Apr 12, 2018 11:16 pm
Your seat bag would look next level with a push to view voltage display on it
Yeah, that would be cool for sure. With such a small pack, I'd be worried about power-draw from hooking up something to display the voltage. I have a wattmeter in my parts bin, but that is always on and draws power from the pack unless you unplug it. One thing I'd been thinking is using both the Luna solid-state switch at the pack, followed by a wattmeter, then running to the controller, but I can't fit all of that into the bag. I've been really interested in the bluetooth BMSes that can not only report overall power stats, but also provide individual cell stats. My concerns—and why I didn't get one for my seat bag battery—was that they look a bit larger and bulkier, and they don't have great (or any) iOS apps. I'd love to just take out my phone and check the stats before or after a ride.
On my bike 12AH 48v going full speed pedaling little the voltage drops from 54.6v to 50v after 18k / 11 miles , I leave the pack sit until the next ride then recharge before leaving and repeat.
Using what I learned from reading its the best way to extend the batteries lifespan.
I'm not sure that's necessary if you're riding every day, but that's definitely good advice if the bike will be unused for more than a couple days.
I measured the pack voltage after one day's commute of about 10 miles. The pack read 49.6V. This is a 7Ah 48V nominal pack with a full charge capacity of 382Wh (54.6V x 7Ah) and after 10 miles it was at 347Wh (49.6V x 7Ah). So in terms of total efficiency with me, the route, and the motor, I'm looking at about 3.5Wh/m (35Wh used over 10 miles).