Sudden drop in GIDS

[bernie82]

Sudden drop in GIDS
My 2012 Leaf (8000 miles) has been reading 272 GIDS during the winter when I had 5 bars on the battery status indicator. The weather got quite warmer recently and as soon as the battery status indicator started to show 6 bars my full charge after balancing shows 262 GIDS, a drop of 10 GIDS. Is this related to the ambient temperture change (5 bars to 6 bars) or is this related to normal battery degradation?

 

[Stoaty]

Is this related to the ambient temperture change (5 bars to 6 bars) or is this related to normal battery degradation?

Probably both. See the Wiki for info on expected rates of battery degradation as a function of climate (highest in the first year, but not necessarily linear):

http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss#Battery_Aging_Model" onclick="window.open(this.href);return false;

 

[DaveEV]

My car has dropped 5 gids on a 80% in the last month from 213 to 208. It has warmed up a good amount in that time, it seems to drop faster with increases in average temperature.

The battery can't lose capacity that quickly in moderate temps, so it must be a gauge error in response to the change in temperatures.

 

[TickTock]

Yup. Mine too. Happens every summer and recovers (somewhat) in the fall.

 

[GregH]

Can you see the 0x55b "real" SOC from the car?
It might be interesting to note.. Sometimes the car doesn't really charge to what we normally call full (95.2-95.6%). This morning my car which can normally get to 277-278 fairly easily only charged to 273.. but then I noted the SOC was only on the low side of 94%. You may find after a few cycles that the Gids and SOC go up.

 

[TickTock]

Yes, I monitor both. I am still getting ~95% SOC on a full charge and pulling ~19kWh for a dead to 100% charge, but my gids dropped 10 in the last 2 weeks. In the graph, ignore the discontinuity in July of last year (Nissan took possession of the car for an extended time and reset the BMS in the process) but you can clearly see the seasonal variation in the gids (blue - actually gids*.08) but the amount of charge the battery can take (0 to 100 wall) doesn't show any such seasonality.