ILCE-7M3 and NP-FZ100 battery charge levels

[MalthouseMark]

Hi I've got a pair of Sony A7iii and I'm wondering about battery charging.

I charge my batteries with a Hahnel Pro Cube 2 charger. Today I was charging batteries for a job tomorrow and when the batteries said they were at 100% I popped one into one of them into one of the bodies and turned the camera on. I spotted that the battery charge level only said 90%. Odd given that the Hahnel Pro Cube said 100%.

(This is an original Sony battery not an after market extra.)

I took the battery out and popped it back in the Pro Cube. Which immediately said it was at 100%.

Ok... maybe the battery is failing?! That's fine. I've got backups. But it confused me.

I put the battery back in the camera and attached a USB cable to charge it "in camera". When the LED light went out to indicate the battery was fully charged I turned the camera on again and it indicated a charge of 95% on that battery.

I can accept that the battery might be failing. I'm just confused why the Hahnel Pro Cube would say 100% but the camera only say 90% (and 95% after charging until LED goes out "in camera").

Any thoughts?

[HannahEd01]

Hi MalthouseMark, the battery capacity decreases with time, and you're using a non-Sony charger for it. I'm not sure why it stopped charging inside the camera on 95% only, but that might be related to its lifetime.