DBMandrake
Posts: 135
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Is my battery dying ?

Wed Jul 03, 2019 1:33 am

As expected, some time after the battery calibration the BMS has made an upwards adjustment of about 1Ah from 32.7Ah to 33.6Ah.

So it seems that when you do the full battery capacity measurement in Diagbox it initially sets the "usable" reported Ah capacity to about 2Ah below the actual measurement of the worst cell in the pack, (33 vs 34.8) and then some time later it will adjust that so that the usable is about 1Ah below the actual capacity of the worst cell.

Here are my latest figures:

Image

Image

Beside the one off upwards correction it is still counting down 0.1Ah fairly regularly, I've seen it drop 0.4Ah in less than a month, which is a lot higher than expected. In short my weak cells seem to be failing rapidly so I've decided that I am going to attempt a cell swap of the four worst cells.
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

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