ElectricGod
10 MW
galp said:Fully charged 20S lithium is 84V. So 16V margin. You have to understand that difference between saying 15V and 18V is insignificant for this case. For example one motor could produce 10V spikes and a different one 20V spikes at same phase current. It's really hard to know how much is enough but 2V difference for sure won't save you at 84V input voltage.
I don't know anybody that charges LIPO or LION to 4.2v per cell. I sure don't. If you look at electric car makers such as Tesla, they don't either...more like 3.9v. Lithium at near full voltage has a non-linear zone where charge voltage drops off quickly until you get into the linear zone at around 4.0v. Charging above 4.1v per cell shortens the cells life span and does not offer any significant amount of extra charge. Same for the low end. There's not much use going below 3.4v per cell and to use them below this just shortens the life span of the cell.
IE: 20S=84v is unrealistic.
![LION%20capacity%20chart%202.png](/sphere/proxy.php?image=https%3A%2F%2Foi1055.photobucket.com%2Falbums%2Fs515%2Frkenders%2FEV%2520Stuff%2FBattery%2520builds%2FLION%2520capacity%2520chart%25202.png&hash=7986eca0a774b56f184ab055489b4811)