Why would my Summit 2 Charger say this State of Charge?

[Buck9s]

My Summitt II charger is showing a 52% State of Charge measurement when my onboard & handheld volt meters both show 50.1%, which according to every online chart would imply an 80%+ state of charge. Does the charge have a different way to measure state of charge? I want to make sure I treat my batteries well so that they last but there is a MASSIVE difference between 50.2V being 80%+ and 52% state of charge.

This was after a 9 mile run this morning at 20+ mph with me and my kids on my 2015 48vTXT with new Trojans (60 - 80 cycles on them).

Thanks for any thoughts and advice.

[JohnnieB]

I'm not 100% sure of this, so you'll probably have to contact Lester or the vendor you got the charger from, but I suspect the charger is looking at the On-Charge voltage to estimate the SoC while the charge is in progress and the charts are based on At-Rest voltage 12 hours after charger shuts off to estimate SoC.

According to the attached Trojan battery charging profile, an On-Charge voltage a bit under 2.35VPC (Volts per Cell), or about 56.4V for a 48V pack (24 Cells) is a SoC of 90%

In other words, I'm pretty sure the charger is counting apples while the charts are counting oranges.

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BTW: SoC charts are battery brand specific. Crown, Exide, Rolls, Trojan and US Battery all have different voltages at 100% SoC.