single channel vs dual channel charger help

[jjvwg]

hey guys, been on a break from the hobby for quite a while now, only flew ~15 flights in 2012 and none in 2013. other hobbies and time commitments have pulled me away. looking to get back into this hobby full time in the coming year and would like to sell my 450 and move up to a 550 and eventually a 700 electric wise. I will keep my 600n. the only electric experience i have is with my 450 and my current charger setup is pretty simple and weak. Looking to get a heavy duty 1000w charger setup going to be able to quick charge/parallel charge multiple 6s packs. ive been looking at chargers like the icharger 306b, 308duo, and the voltz 101k. what im trying to figure out is what the differences and pros/cons are of single channel vs dual channel chargers? it seems that the voltz 101k and icharger 306b are basically the same charger, with the 101k going for just over $120 on ready heli right now with the BF deals. what I like about the 308 duo is i could use one channel to charge multiple 6s packs at once at 1c, or charge maybe two in parallel at a higher rate and then charge receiver packs on the other channel. can someone explain the synchronous (50A output) vs asynchronous (30A output) modes to me. do you hook up between the two channels in synchronous modes! thanks for the answers guys. looking to take advantage of BF deals this weekend and need to make a decision.

[RedOctobyr]

My background in the hobby is different, but I just ordered a 308Duo, upgrading from my 106B+, so I can give you my thoughts on dual-channel, FWIW.

Yes, a pair of 306Bs would give you 30A/750W per channel. This is more than a 308Duo can give. It will do 30A/750W on either channel, but there is a 1300W overall limit (vs 1500W), so about 26A on 6S, if running both channels at the same time.

The 308Duo offers the benefit of being a single charger to manage. It has a much more informative screen. It has a servo tester, etc. It has 1.2A of balance current per channel, vs 0.5A balance current for the 306B/3010B. It can also discharge from one channel, into the other channel, if you have an external resistor/bulb setup connected to the second channel. This avoids putting the discharge heat into the charger, keeping it cooler, but it can still provide a faster discharge; my ~$20 resistor setup can give me a 400W discharge.

And if you're approaching overloading your power supplies (or generator), you have a single place to set current-draw limits. So it can do things like bias full power to one channel, at the expense of the other, while still hitting the overall limit you set. With 2 separate chargers, you need to set current-draw limits conservatively (eg- limit each charger to half of the max you can supply). And if one charger finishes, the other can't automatically increase its charge current, now that the first is no longer pulling anything. A single dual-port charger *can* increase the power to channel 2, once channel 1 finishes.

For synchronous mode, yes, you join the main outputs of both channels, as well as joining the balance outputs. Now you can get 50A/1300W, whichever comes first. You also get twice the balance current, 2.4A, vs 1.2A, so big packs can balance more quickly (so this could speed things up even if you were only charging at 20A).

With each channel operating independently, your total wattage output is still the same. But you "only" get 1.2A of balance current.

Sync mode is nice for a bunch of big 6S packs in parallel, where for a fast charge you really need a lot of watts and current. But I could see it also being handy for things like cars, where you might be running 2S 5000mAh packs or something, where you don't need a lot of watts, but you *do* still need a lot of amps. And maybe having "only" 30A is limiting you