high charging voltage

No, verify that with a meter.

Ref: ..."Charging Gauge"  ...  ???

Did you mean to say  High Charging Current(Amps) or High Charging Voltage?

25 Amps settles to 8 Amps?  OR 25 Volts settles to 8 volts???

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We will need some background information.

What Aircraft?

What engine?

What Battery?

Is the battery normally kept on a maintainer?

Did the battery die in storage?

Is this a new issue?

What changed/Happened/Didn't happen between the last time you considered it Good and Now.

What numbers are you used to seeing?

I am talking Amps Voltage always looks good while running

912 uls

kitfox

lithium battery 16 months old ,no maintainer

2 alternators

I did run it down   about a month ago working on radios but showed 10 volts and it charges fine with a special charger

I didn't do anything different and always jumps up after cold start but is seams like it stays on a bit longer now.

I think  8 to 10 amps is normal . It runs 2 dynons, strobes and Navs all the time.

It seems like it has always done it and the factory said not to worry about it if it is charging ok. Sometimes I think the Dynon is so sensitive and shows more detail than a normal gage.

I called this High voltage but it is high amps not volts, Sorry

Starting the engine puts a drain on the battery. Lithium batteries, unlike lead acid batteries, can accept large charging loads even when they are near full. So it would not be unexpected that immediately after starting, the amp output would be high and then quickly taper as the near full battery becomes completely full. Do your readings represent a change in charging behavior, or is this how it has always behaved (with the lithium battery)?