Just found this on Amazon. Pretty interesting. Says it can charge 2 battery at once and 5 batteries total.
https://www.amazon.com/dp/B0789JDL4C/ref=cm_sw_r_other_apa_rCSSAb35C95PF
https://www.amazon.com/dp/B0789JDL4C/ref=cm_sw_r_other_apa_rCSSAb35C95PF