Why Charge to 80% and the use of smart BMS in Zen 52V,20Ah UL-2271 battery

[Ravi Kempaiah]

One of the features that we have implemented in our Photon Pro and Ultra bikes with 52V, 20Ah batteries is the smart BMS with the adjustable limit for an increased lifetime.
These modes can be changed with the simple click of a button on the control display. I don't know of any other E-bike that comes with such a feature. Our hope is that people make use of this feature and prolong the life of the battery.

You may want to watch this video to understand why 80% charge benefits the overall lifetime of batteries. It's not just us, Tesla and Apple also recommends 80% charge for batteries [see image below]

 

[il Munduato]

My Samsung tablet.
They've had this feature for years.

I've been following this advice from Battery University and set my version of the DIY Smart Charger to optimal charge voltage (51V for a 48V battery) by default

In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; going lower may not gain further benefits but induce other symptoms(See BU-808b: What causes Li-ion to die?)



@spokewrench... just another fad

 

[mbremner]

Hi Ravi,

I believe that I have seen some discussion of occasionally charging to 100% in order to "balance" the cells. What is your recommendation regarding this practice? If you recommend it, how often do you think it should be performed?