What would you do?

[BrianG]

Wouldn't hurt to find out...

[lucias]

If I bought one from tanic it looks like the APC - 30 would be big enough, it is 400w If i am looking at it right..

[BrianG]

If you want to use the full output power capability of the duo charger, I'd step up to the next level. 30A @ 12v is 360w on the button. Don't forget, the charger will use up ~15% of that from inefficiency, so you'd be left with only 306w for the batteries. Either way, you'd be pushing it at its max, and it's always better to allow for a little headroom. I'd go with the 45A model (540w). Even accounting for 85% charger efficiency, you'll still have about 15% headroom when the charger is at full tilt.

For the price of the charger and power supply combined, you could just get a CC/CV power supply instead, and charge any lipo directly off it. Just set the max current (1C) and the max voltage (4.2v/cell X # of cells). Of course, this method does not have the added safety features of a real charger by detecting the proper settings based on the pack connected, so be careful. However just shy of 12s @ 20A is pretty darn nice. https://www.tanicpacks.com/product_i...74f16af042a459

[lucias]

I didn't read it that way... I am glad people like you are around that the geniuses while I am the nooob...

[BrianG]

If the 30A model is 400w, then the actual output voltage must be 13.33v. Even so, the duo is gonna pull over 420w at full capability, which is pushing the 30A PS beyond its rating.

Of course, this all assumes worst case current draw. Are you going to be charging large capacity packs at high currents? Also, the most power drawn will be during the CC stage, right where the cells hit 4.2v/cell. This is not a whole lot of time. I tend to be conservative in rating everything; things just last longer that way. Could you get away with the 30A model? Probably.

[lucias]

Sooooo I got my used MMM (looks awesome) and the 1521 is freaking long... I think I am getting a cough at work... my only problem is rode my bicycle today and my GF borrowed the truck so I dont have keys to get into my house.. BAH!