That depends on the size of your batteries....If I remember correctly the Polycharge will charge 4 at once but only at 1 amp....If this is the case and you're trying to charge 4000ma batteries, it will take all day to charge them....I think I used my Triton to charge a ThunderPower 3S 2100ma at 1 amp, once. If I remember correctly, it took several hours. I think, since you already have one Triton, I'd take the money and buy a second one. The Triton can charge almost any battery in about an hour...JMHO....Pat