Would you then expect to see drastic changes in the histograms they presented? I'm not sure their conclusion statements would be invalidated, but perhaps they should try again...'double-down', as it were.
edit: I don't like this sentence, though: "Though the battery banks were comparable in ampere-hour size, the deliverable energy of the lead acid at the high discharge rates and lower temperatures rendered this battery bank nearly useless when a protective low-voltage threshold is implemented in the electrical."
This should be revised and clarified, imho.
As one would expect with known issues related to both cold temp capacity and reduced capacity with high current, the conclusions would be correct in direction, but the magnitude would be notably muted.
Furthermore, lead acid batteries intended for power systems often have additional data available that include low temp capacity and a logarithmic charge for Peukert effects.
Here's an excerpt from the T-1275 datasheet (familiar with these. I have 12):
At 80A, you'll get an estimated 70 minutes. Note that while the chart is an estimate, this battery has a 70 minute 75A rating, so lets say 65 minutes. At 15°F, you'll get about 55%.
Combining the two, a 150Ah battery will have a 87 * .55 = 48Ah capacity. Reduce that to 24Ah for the 50% rule.
24Ah out of 150Ah sucks, but it's better than 0, which is what you get every 2nd, 3rd, 4th, etc., discharge with LFP, but at least FLA/AGM can give you 24Ah each time you charge it at 15°F (absorp at 15.86V).
Note that while I'm using a 150Ah battery as an example, this single battery capacity is LESS than the two paralleled batteries they used (210Ah).
This is all just known stuff. BB presented it in a biased way with a poor experimental design looking to diminish their disadvantage associated with cold charging. Had it been just fluff on a webpage, I wouldn't care much, but to develop a "whitepaper" and attempt to come across as scientific is disingenuous.
I'll go away now.