new headlamp with COB led, 18650, Test W606 and W608, disassembly, ideal headlight?

small https://www.ebay.com/sch/i.html?_odkw=cob+10w+headlamp&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xcob+10w+headlamp+18650.TRS0&_nkw=cob+10w+headlamp+18650&_sacat=0 big https://www.ebay.com/sch/i.html?_odkw=cob+30w+headlamp+18650&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xcob+30w+headlamp+18650+3000lm.TRS0&_nkw=cob+30w+headlamp+18650+3000lm&_sacat=0 bike led COB red + white https://www.banggood.com/XANES-2-in-1-500LM-Bicycle-USB-Rechargeable-LED-Bike-Front-Light-Taillight-Ultra-light-Warning-Night-p-1191651.html?p=X31112959911201412JB