Having recently upgraded the display on my Bafang mid-drive e-bike, I’m now an advocate of displays that provide actual battery voltage, rather than just a relative indication of charge via bars. Here’s what I’m talking about. Here’s the display I’m using on my two rear hub e-bikes. It’s the SW900 LCD display:
It’s not a bad display. It just doesn’t give me all the information I would like to have about my battery.
Better is this display I recently purchased for the mid-drive e-bike. It’s the Bafang 850C/DPC14 LCD color display.
You’ll notice next to the battery indicator, there’s a an indication of the actual voltage remaining in the battery. Why is this important you might ask?
Glad you asked! In previous posts I made the point that you can potentially improve the longevity of your battery by not letting the charge level get below 20%, and when recharging, charge to 80% most of the time. I only do full (100%) charges about every 5th charge to re-balance my battery’s cells.
Now, since I said 20% for the lowest discharge, and 80% for the highest charge, how many volts does that relate to when charging a 48 volt battery? Good question! After much digging, I this excellent resource which answers the question: https://talesontwowheels.com/2019/10/02/li-ion-ebike-battery-charge-charts/ (thanks to Matt Robertson for doing the heavy lifting to make this information available to us all!)
From this ’48 volt’ chart, I conclude that I should not let my 48 volt battery discharge below about 42 volts, nor charge more than about 51.5 volts with an 80% charge. To manage this charge level, I have been using the Luna Charger 48V Advanced 300W Ebike Charger (currently out of stock), though this charger works just as well, is in stock, and costs less – 48v 3amp Luna Mini Charger.
And just to add a little more weight to my claim that charging your battery to 80% rather than 100% as a routine thing, here’s yet another chart (source):
That’s all for now. Thanks for listening!