But where is the test data?
@RetiredBA/BY
The characteristic curve graph on page 2 of the LVP65 datasheet indicates 4.025 volts. i would attach an image showing this but don't seem to have image upload privileges.
@mm43
i did see that statement in the report about passing an overvoltage charging test and was quite puzzled. i would love to see that test data. So far i am at a loss to understand or explain how the battery could survive a 36-volt overcharge (4.5vpc) for 25 hours without seeing the corresponding current profile--voltage without current is meaningless.
On page 21 of the latest JTSB report there is a graphic showing both battery and cell voltage ranges for the 4 BMUs. i have not translated it yet but it shows some captions at the 36.5 volt pack level and also for the 4.55 volt cell level.
Could it be that the contactor opens when the terminal voltage exceeds one of the BMU limits on the high side just as it does at the low side? -- in which case the 36 volt overcharging claim is a legally true statement, but lacks technical integrity.
Why the curious 25 hour limit? A 2.6 amp contactor coil current would use up the entire pack capacity in 25 hours (2.6 x 25 = 65 Amp-hrs), in which case the contactor would return to it's normally closed position and a large potential would be applied across the depleted cells with a huge charging current exceeding 1C.
i have taken thousands of laboratory measurements of voltage, current and temperature on several dozen lithium iron phosphate (3.2 v nominal) cells while under high-rate (1C) charging and discharging. Even though the Yuasa cells are a different chemistry, i am quite certain that a true 36 volt charging condition (4.5 volts per cell) would rather quickly be spectacular to watch from a suitable bunker.