Your efforts really helped me an in particular:
Quote:
|
At 1C dis/charge I saw a pretty constant 4F above ambient in cell temperature. The cell heated up very uniformly. The terminals I thought would heat up as well, but they always remained at a lower temperature than the cell. This may be due to the large aluminum blocks on them.
|
I'm going to treat the tabs as heat radiators as much as possible. Compared to the poly bag, they should do a reasonable job of dumping the latent heat from the battery. When I get my cells, I will test this by using an IR thermometer to see if there is any detectable temperature gradient from the tabs down. The video suggested this approach for heat management.
I have a boat-load of things to test but I suspect that if I group balanced cells, I can detect the earliest dV/t drop. I may also go with the Prius trick and measure voltages in pairs which a single battery monitor chip can handle. I'll still go with the per-cell, Zener balancing array but the voltage monitoring is just to disable the string when the first cell pair begins to fall off the discharge edge. <grins>
Every time I can simplify the design, the parts count and risks go lower. <grins>
Bob Wilson