Percentage of charge

[TLC]

Just wondering if I charge my battery to 90% 53 volts and after the ride the battery is at 50 volts when put on the charger or if I charge my battery to 80% 52 volts and when I return and put it on the charger it reads 48 volts. Whats the percentage of charge did I use and how many charges can I do to count as a full charge. Thanks

 

[harryS]

Cell manufacturers define a full charge cycle as going from 4.2volt down to 2.5volt. Translated to a 48V battery, that would be 54.6V down to 32V, but your ebike shuts off around 42V, so you never get close to a full cycle on an ebike. Makes a big difference. And your charging habits makes even more difference.

In the first case, you start at 90% and drop down to 60%. Second case is 80% down to 50%. About 30% for both. This is just a guestimate on my part, but I think that staying above half charge is much less severe than 80%-20%. Gotta be 2X, maybe 5X better. Pick either one 90% or 80%, but I think you're in no danger of premature battery wear.

 

[TLC]

39V ?

 

[harryS]

39V? That's what LVC would be if the controller designer used 3.0V/cell as a minimum. On this dual voltage model, it's 30V and 40V. In real life, I find voltage sag shuts them off about 2V higher.

 

[TLC]

In the future I will charge the battery to 80% after each ride and on days that I know will fast and long I will charge to 90% the morning before I ride. Then once a month I will charge to 100% to equalize the cells.
harrys I have my controller set to shut off at 42 volts but the battery shuts off at 45volts quess its the BMS card doing this.
Since my whale shark $700 battery went bad after a few miles I just trying to figure out how to make my battery last a long time. Thanks everyone.

 

[harryS]

Bummer. Did you get a replacement on that whale shark?

 

[TLC]

No E bike Essentials doesn't warranty their battery if you read their web page it states they don't take returns on batteries plus I couldn't ship the battery back no one would ship it because of its size. It was a 13x7 so I took it apart and found one set of seven cells bad. So I built a 13x6 battery out of the good cells..If I had it to do over I would never purchase a battery I would built one using a good name brand cell

 

[Gionnirocket]

No E bike Essentials doesn't warranty their battery if you read their web page it states they don't take returns on batteries plus I couldn't ship the battery back no one would ship it because of its size. It was a 13x7 so I took it apart and found one set of seven cells bad. So I built a 13x6 battery out of the good cells..If I had it to do over I would never purchase a battery I would built one using a good name brand cell

How did you make the connections between the cells?

 

[TLC]

I first purchased Vruzend kits but I had problems some of the end cracked and I thought this might lead to problems later but the biggest drawback was that it was just too big and too ugly. Took it back apart and ordered a cheep pot wielder. Built the battery and installed it back in the Whale Shark case.