The VL-4S is a fully simultaneous 4-channel charger, housed in a high-impact, polycarbonate enclosure with a recessed power switch and carrying handle.  Quick and powerful charging make the VL-4S the perfect choice for broadcast and production facilities with a high battery usage. Each channel is operated independently so batteries can be placed on charge in any order and at any time.
https://idxtek.wpenginepowered.com/sites/default/files/product/datasheet/VL-4S_Manu_E_0607.pdf
https://cvp.com/pdf/vl_4s.pdf