Understanding Lithium Vs. Lead Acid Help

[DaveTM]

Originally Posted by Murby

What is the amp-hour capacity of your leaf pack?

Here's a pic of my pack "in progress". 14 Leaf modules is 120 AH. A 7 pack leaf is 60AH. With all of the "Leaf" builds that have been posted on this site, I think it's common knowledge that a 7 pack is 60AH and a 14 pack is 120AH.

[Sergio]

Murby, I get the point You are trying to make, however the word "just" in your comment is not accurate for that example.

A large pack that is out just 300mv could lose 5kw of capacity until those cells are balanced

Looking at the Leaf cells we use, the difference between 3.6v and 3.9v (300mv or 0.3v) represents approximately 50% of the available capacity.

That is not a balancing issue and purchasing an expensive BMS is not the best solution.

If one does not understand the implications of trying to connect a cell that differs that much in voltage from other cells they should consider buying a pre-built lithium pack.

Your experience with the Volt cells is not unique to the Volt cells, all Lithium chemistries behave in that manner.

The balancing circuit of a BMS is simply designed to maintain the cells in a pack in balance due to normal aging process of the cells and minor differences in cells construction and not to equalize their charge.


Edit:

DavidTM unusual wiring above is because he is in the process of "equalizing" the voltages of his cells prior to connecting to the BMS.

[DaveTM]

Originally Posted by Sergio

Edit:

DavidTM unusual wiring above is because he is in the process of "equalizing" the voltages of his cells prior to connecting to the BMS.

Yes.....my "balancing wire" is not what you would call "neat 'n pretty"....but it did get the job done!!

As the install job progressed.....I do get "more neat" as it went along!! This pic below shows the batteries installed....but the wiring was not yet completed.