After turning the calculator on, press the green "2nd" button, then press the "+" button. Continue this until the contrast of the display is to your liking.

It actually doesn't charge the battery (which is a standard CR2032, as noted on the back of the calculator), it will power the calculator instead of using the power of the CR2032 battery.

I don't think you can get a replacement battery for this device anywhere. It is a 950 mAh 06220 battery made by Jhih Hong Technology. The model number seems to be BAT000023 and the type is 1ICP4/44/59.

Does yours have the MFG PN # MT24078?

I don't think you can get a replacement battery for this device anywhere. It is a 950 mAh 06220 battery made by Jhih Hong Technology. The model number seems to be BAT000023 and the type is 1ICP4/44/59.

@richy14330 The connector type is JST ACHR-03V.

I'm not sure you can get this same battery somewhere else (I haven't performed a battery change myself, just took it apart for demonstration). I'll get back to you if I can figure out a way to use another battery.

Ibis (the original maker of this guide) had 4 Samsung INR18650-30Q cells installed. These are 3.7V unprotected 18650 cells with a 15A continuous discharge rate and a capacity of 3000 mAh.

I'm not sure if you can find the displays anywhere. The only number (presumably model number) I could find on the screen was AM0310R-04 and the Lot Number NHT18080052.

I'm not sure if you can find the displays anywhere. The only number (presumably model number) I could find on the screen was AM0310R-04 and the Lot Number NHT18080052.