6 Month Battery SOH

[Bricktop X PWR]

Had a little play with an ancient OBD dongle I've had knocking about the shed and found 'Car Scanner' now had an MG4 Profile.

Doesn't cover very much but it did give me a State Of Health (SOH) reading for the battery.

The car was built 1 year ago and I know six months isn't a long time (my ownership)
I DC Fastcgarge 99% of the time and try and balance at least once a month.

SOH is indicated at 100%

I not sure I trust it though because it was showing the cars battery at 60% whilst the car was saying 66% (GOM in effect?)

 

[tsedge]

Had a little play with an ancient OBD dongle I've had knocking about the shed and found 'Car Scanner' now had an MG4 Profile.

Doesn't cover very much but it did give me a State Of Health (SOH) reading for the battery.

The car was built 1 year ago and I know six months isn't a long time (my ownership)
I DC Fastcgarge 99% of the time and try and balance at least once a month.

SOH is indicated at 100%

I not sure I trust it though because it was showing the cars battery at 60% whilst the car was saying 66% (GOM in effect?)

View attachment 25425

Because there are buffers built into NMC batteries at the top and bottom end (to prevent overcharging and overdischarging), these are traded off somewhat in the first couple of years as the battery ages, masking actual degradation.

This is why NMC batteries have a "usable" rating separate from actual. We have 64kWh batteries but only 61kWh is usable.

Therefore seeing 100% or 99% in the first couple of years is normal. The degradation will increase beyond that, but only relatively slowly.

 

[powerfulx]

Interestingly the degradation is quick in the first few years then plateaus out.

 

[DaevM]

I had a 30kwh Kia soul ( lithium ion battery) for 5 years, 45k miles still showing as 100% soh. Always charged to 100% ac, 94% dc if required . Never took any special battery management precautions. I believe there was buffer capacity, but even so, still impressed given warnings about future degradation.
I would have thought this much further down the line that technology would've progressed sufficiently that things would improve rather than the opposite ?