I use my battery very similarly to you.
To be accurate, my battery is a 52 volt nominal, Lithium Ion, PA cell battery. Rated at 11.5 AH. And every thing stated below will relate to Li-Ion chemistry.
This is the chart that I use for battery charge/voltage comparison...
![](https://i.imgur.com/qRpmAux.png)
It seems to go along with recommended voltages per cell at different percentages of charge.
IE: 100% = 4.2 volts per cell X 14 cells in series for a 52 volt nominal battery = 58.8 volts DC.
50% = 3.6 volts............................................................................... = 50.4 volts DC.
0% = 3 volts................................................................................. = 42 volts DC.
That said, my recommendations are as follows for longest battery life.
Leave your battery charged at 100% for the
shortest time possible. IE: Charge to 80% and then just before using, top off to 100% just before riding on an extended trip.
Do occasionally charge to 100% depending on use, to allow your cells to be properly balanced by your battery's management system. (
BMS) Otherwise 80% is fine.
Using your battery in the middle zone of voltages would seem to be to your advantage as seen by this capacity retention/cycles verses voltage chart.
![](https://i.imgur.com/YHl1yqt.jpg)
Store your battery at around 50% charge, checking on it occasionally.
And to actually address your question of how low should I go...?
Our controllers will hit a Low Voltage Cutout of around 3.2 volts per cell or so. (@48 volts nominal) So for a 52 volt nominal battery, this would be equal to a charge of 44.8 volts. This would probably be the
lowest recommended usable voltage.
![Shocked :o](https://goldenmotor.com/SMF/Smileys/default/shocked.gif)
But as mentioned earlier, staying in the
middle voltage range will pay off in the long run. And for riders like you and I that don't need the absolute maximum capacity, is where I'm staying.
Regards,
T.C.