YX8018 ~about "guessing the operation"

→NB←! the following has pretty much nothing to do with the actual chip !!! ←
i just matched some known or guessed data into random simulation substitute

from what we can conclude ::

1. the device operates best at certain fixed supply voltage (there might be one built in to YX8018)
2. the best efficiency is occurring below the certain output power = you should not replace the inductor to lesser inductance one without making sure :
   a) that there's enough power to drive the inductor (somewhat aided by the 1µF and 5µH caps inductors at the schematic) ,
   b) that the inductor won't be driven into saturation
   ( ↑↑ ← both are primarily indicated by a notable drop in efficiency compared to initial -- however the lesser inductance does, by the idea, give a* higher output power and usually there is some efficiency drop for "trade" to such* )
3. the onboard inductor in my particular solar lantern has 4Ω series resistance (it might be useful to protect the mosfet from peak power ? from accidental out of cycle re-trigger . . . or provide some voltage regulation for more up to charge battery) , otherwise there's a plenty of room to install a better inductor (such might also cause the over-voltage at the switch drain -- it must be tested out at max input power)

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BWD engineering the GPSA006W3

very apx.* op. of the Solar Charger

PS! the numeric values on the plot are illustrative*

the valid formula for thishit seems to be ::
IF no clouds
prod. ( ( 8h/d + 4/2 h/d = ) 10h/d ) × 43.6mA = 436mAh/d
apx. 5d to charge batteries from 20% to 100% of nom. capacity
( usually it takes 2 to 3d . . . ? 55% to 95%  e.g 4x SB in parallel (60 in²) should 2 the 3-ck in 1d )

Update : results of a "Quick Test" (applies to solar cell only) ::

EP -- ( values below (have likely 1.5 to 2.5 significant digits !!!) ) based on solar-cell´s double output power !!! or max. power diffused on internal resistance at short circuit !!! -- sampled on 2 spring afternoons @ apx.60°N (Sun filtered by Space´s dust + Earth´s atm..+ packet-window´s 2-ble layer of Si-glass)

Est.Peak double output power ( P_2PK (= ε · r) ) : 1.163698202 W
*Speculative "no load" terminal voltage ( ε ) : 6 V
*Computed internal resistance ( r ) : 30.935856 Ω

note : * --  the values are valid for P_2PK or at max. "intensity of a Sun" and will respectively drop,increase at lower intensity levels + there are reason to believe that ε , r also depend on load ( I²R )

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Update+ : refined experiment (sampling the I , U and ε) ::

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