Battery Upgrade to 40 KWH update 2011 Leaf
I ran the car down to a 6-mile range to test recharging, but the next morning, the car did not recharge to 80% as programmed using my Blink wall unit. The car had been working flawlessly before, so what went wrong?
When I anxiously tried to check what had happened, I found the car was completely dead! Nothing worked—not even the emergency flashers. Initially, I thought I might have disabled the computer by attempting to upload a map upgrade (which I later learned isn't possible on early Leafs).
After analyzing the issue all night, I determined that the culprit must be my almost-new 12-volt battery. I jumped it, and the car came back to life! From there, I was able to recharge the car to 100%.
I immediately checked the system using my new LELink OBDII scanner (which, by the way, showed nothing when the car was dead). With the car operational again, I could finally check the drive battery health to confirm I was getting what I paid for. GreenTec warrants a minimum of 85% state of charge (SOC) on the 40 kWh battery, and my results showed 86%.
However, I learned from other blogs that the GIDs give a better indication of the cells' true health. Leaf Spy reported 438 GIDs. But what does that mean?
Well, ChatGPT came to the rescue, providing an explanation: 87.6% health.
FYI, here’s the calculation:
If your 40 kWh battery shows
438 GIDs when fully charged, we can calculate its health by comparing this value to the expected GIDs for a new 40 kWh battery.
Steps:
- Calculate usable capacity:
- Each GID represents ~80 Wh of usable energy: 438GIDs×80Wh/GID=35,040Wh(or 35.04 kWh).
- Determine battery health (State of Health, SOH):
- A new 40 kWh battery would provide approximately 500 GIDs: SOH=Original CapacityCurrent Usable Capacity×100 SOH=40kWh35.04kWh×100=87.6%.
Conclusion:
With
438 GIDs, your 40 kWh battery has about
87.6% health. This is considered good for a used or refurbished battery, as a slight degradation over time is normal. Keep monitoring the GIDs and overall range to track future performance.