Yeah I figured it had something to do with that.
It's out of 91 kWh now. So 84.5/91 = 92.5% health which where the parameter should be. Try to charge up to 100% a couple times in a row after draining it down, then repeat again in two weeks. Hopefully that gets your SoH parameter back up to the 90's.
Oh that's what they did in that recent update to change the SOH.
Interesting you should say, just run a check on my battery at 91% SoC and cell voltages are all around all within a few thousandths of a Volt of 4.03V so quite balanced.After learning how much more important a "balanced" battery is than the usable capacity of a battery, I personally consider the real SOH of my EV battery is reflected here:
Exactly.Interesting you should say, just run a check on my battery at 91% SoC and cell voltages are all around all within a few thousandths of a Volt of 4.03V so quite balanced.
SoH running at 92%.
86,000 miles & 35 months old.
The way I understand it, that weakest cell can hide its weakness at a high SOC (not vary as much from the pack), but increases its variation of voltage from the rest of the pack as the SOC lowers?
Yes, if the pack is top balanced, then you’ll see the biggest voltage deltas when the pack is at low SoC. The BMS keeps track of these voltage deltas versus SoC and uses that to determine the individual cells’ capacity. The BMS in the Mach-E is a little bit more sophisticated than the leaf, so you shouldn’t see as bad of dips in SoC under load.The way I understand it, that weakest cell can hide its weakness at a high SOC (not vary as much from the pack), but increases its variation of voltage from the rest of the pack as the SOC lowers?
On the Nissan Leaf, at high SOC, the variation between the lowest voltage cell and the highest, might be ~20 millivolts. Considered healthy, by Leaf standards.
But that same cell might vary by 400 millivolts as the SOC of the whole pack drops lower. Say 30% SOC. (or lower)
Suddenly the car under load will drop SOC instantly and range dissappears before your eyes. Turtle mode can trigger as well.
Unlike carscanner, LeafSpy shows the voltage of every cell in real time. And the current variation/delta of the lowest/average/highest cell. (see below)
Each vertical line is one of 96 cells.
6mv is the delta (very good)
SOC of the pack is 95%
The delta always increases at lower SOC. So you can't be sure when shopping for a used Leaf unless the seller will allow at test drive at a lower SOC. The lower the better!
Same Leaf at 38% SOC.
Delta has only increased to 17mv.
SOH says 88% at 6 years old. But battery is still really healthy for a Leaf considering.
I got my EV teething on a Leaf. It was a great car for a newbie, and a low risk bargain!
That car was absolutely responsible for leading me to the GTPE.
After a few cycles, my SOH now says 95% which is close enough.
