When it comes to charging convenience, Venom’s Pro Duo AC/DC juice box literally stands tall. Thanks to its high-instead-of-wide configuration, it only takes up about as much bench space as a pair of battery packs. Inside the case, there’s enough transformer power to fill two batteries simultaneously at up to 7 amps each, and Venom supplies a pair of balance boards and every type of plug you might need to pump life into everything from a receiver pack to a 6S LiPo. All the programmability you expect of a modern higher-level charger is built in, with modes for lithium and nickel battery chemistries as well as lead-acid batteries.
Programming and Setup
Prepping the Duo for duty is just a matter of jacking in all the cords. There’s an AC cord, of course, as well as alligator clips that plug in via an XT60 plug for DC power. Standard 6mm ports accept the banana-plugged charge leads, and JST-XH balance boards are provided. Particularly welcome are the extra-long charge leads and balance-board leads. It’s a drag when your charger forces you to tether your packs just a few inches from the charger, especially when you’ve got LiPos in charging bags. The Duo’s long leads let you arrange your benchtop as you like while the packs juice up.
The Duo programs with the same logic as many other chargers on the scene, so it will be familiar to many users. But even if the Duo is your first programmable charger, you’ll find it easy to learn. Basically, you scroll through parameters, use up/down keys to adjust values, then click a key to enter. After one run through the manual, you’ll have it down. Each charging channel is programmed and operated independently, so you can charge dissimilar packs at the same time. Only one pack’s data is displayed at a time, but you can toggle the display between packs while charging is in progress.
The Duo can charge all types of lithium packs: lithium polymer (LiPo), lithium ion (Li-Ion), lithium iron phosphate (LiFe), and the latest high-voltage (LiHV) packs. Each gets its own specific ending voltage, so make certain to make the correct cell-type selection when you set up the Duo. Balance Charge, Fast Charge, and Storage Charge modes are available for all lithium types. The Fast mode will get on the track quicker, at the expense of reaching full battery capacity. Storage mode, as its name implies, will charge or discharge the pack until it reaches approximately 50 percent capacity—the preferred level for extended downtime.
If you’re charging NiMH or Ni-Cd packs, the Duo allows you to set the peak sensitivity independently for each pack type. Cycling is also offered for nickel packs, with a 1-amp discharge rate and adjustable “waste time” between charge and discharge cycles.
I’ve reviewed a few other chargers with the same programming system as the Duo, so I instantly felt at home programming and operating the Duo. The unit’s dual fans are audible but not obnoxious, and the charge-complete alarms (or error alarms, if you goof) are loud. Long charging sessions did not faze the Duo at all; it just kept pumping amps. An especially welcome feature of the Duo is its form factor; the small footprint and long charge leads freed up bench space, so I had more room to do other tasks while I charged batteries. The only thing I missed was a USB port, which is a handy convenience for keeping my phone alive but not a critical feature.
If you’re shopping for a charger, you’ve already discovered that there are a lot of models out there to choose from. Venom’s Pro Duo sets itself apart with thoughtful features that make a difference (small footprint, long leads) and plenty of value. For $100, you get ample charging power, full programmability, and all the plug types you need to charge all popular RC packs. Nice charger.