[kjfishman]

My K50 won't power on with fully charged OEM battery or after market battery but will power on with the AA adapter with only 6.2 volts. Any thoughts or sugestions?

[bwgv001]

You have a second camera? Do the batteries work there? what is the voltage?

[Not a Number]

Check/clean the contacts in the camera body.

With the AA batteries installed set the battery type for the OEM battery, shut down, then change the batteries.

[kypfer]

Don't have a K-50 to look at, but does the AA adaptor use a different set of contacts in the camera than the DLi109 battery? … if so, try cleaning the DLi109 contacts (don't sand/file them!).
You quote 6.2v for the AA adaptor … does this mean you have a volt meter? If so, check the voltage on the two "normal" batteries. It's not unknown to have two faulty batteries!
The appropriate terminals are marked + and - … you can ignore the T and D terminals for this exercise.
My recently charged OEM DLi109 reads 8.33v off-load, despite quoting 7.4v on the label

[AstroDave]

My recently charged OEM DLi109 reads 8.33v off-load, despite quoting 7.4v on the label

That's just about right for a fully-charged battery (Battery Capacity / Discharge Measurements - Pentax & Canon OEM versus Generic - PentaxForums.com)

[kjfishman]

You have a second camera? Do the batteries work there? what is the voltage?

The OEM style are reading 8.2V and the AA 6.4

---------- Post added 01-19-2022 at 06:43 AM ----------

Check/clean the contacts in the camera body.

With the AA batteries installed set the battery type for the OEM battery, shut down, then change the batteries.

That did the trick thank you!

[photogem]

My K50 won't power on with fully charged OEM battery or after market battery but will power on with the AA adapter with only 6.2 volts. Any thoughts or sugestions?

AA rechargeables have more mA and a deliver more power

An old original Li-Ion and particular almost all older 3.rd party batteries will have maybe 8.2V but not much power (mA)

Also 3.rd party batteries cheat, the lack the temperature sensor and thus could not be charged with the orig. charger.
But the trick the orig. charger with a resistor having the same impedance as the temperature sensor.
That is why 3.rd party chargers have only 2 contacts instead of 4.

Contacts need of course to be clean.
But if AA's work a good Li-Ion should do so as well. If not it is old and has aged.

[photogem]

Don't have a K-50 to look at, but does the AA adaptor use a different set of contacts in the camera than the DLi109 battery?

Same contacts of course!

[reh321]

AA rechargeables have more mA and a deliver more power

An old original Li-Ion and particular almost all older 3.rd party batteries will have maybe 8.2V but not much power (mA)

Also 3.rd party batteries cheat, the lack the temperature sensor and thus could not be charged with the orig. charger.
But the trick the orig. charger with a resistor having the same impedance as the temperature sensor.
That is why 3.rd party chargers have only 2 contacts instead of 4.

Contacts need of course to be clean.
But if AA's work a good Li-Ion should do so as well. If not it is old and has aged.

The extra ‘power’ {amperage} of the AA batteries might make a difference in this case.

[photogem]

The extra ‘power’ {amperage} of the AA batteries might make a difference in this case.

That is very possible.
4 x AA's with 1900mAH deliver more than the Pentax Li-Ion D-LI109.

But that is mainly how long they can deliver.

Otherwise 2400mA/h would have even more power which they don't

It is the way good AA's (or Lithiums) deliver their power or... how they don't go "down onto their knees".

But the original Pentax Li-Ions are very good. Not so 3rd. party versions for many reasons.