Creation date: June 13, 2012
Once again thanks to Dale at EPBuddy for sending me the latest ParaBoards for review.
Over a year and a half ago I wrote my first ParaBoard review. Early on in the age of parallel charging, the average hobbyist was fairly well informed and understood the dos, don'ts and risks associated with this extremely effective method of charging. They had to make their own parallel charging setups and they had a vested interest in doing things right. Since then parallel charging has exploded. It is now the standard practice of hobbyists everywhere and with this frequency of use, problems have arisen. Factory parallel charging cables and boards are now available for purchase, and the average hobbyist can now parallel charge with little to no understanding of what they are doing. The odds of these uneducated hobbyists frying wires, damaging components or even starting fires is higher than ever. To help solve this problem, there are now several safer alternatives and two of them are the new ParaBoard V3 and Micro ParaBoard from EPBuddy.
A simple solution to saving balance wires
To limit current flow between sets of balance balance ports. Polyfuses are polymeric positive temperature coefficient devices that are used to protect against overcurrent faults. In simple terms, these little guys block current when they overheat, and self reset when they cool off. This makes them perfect for creating safer parallel charging boards. Some polyfuses have a temperature sensitive paint on them that changes color when they get hot to alert the user that there is a problem.
EPBuddy's ParaBoard V3
Dale over at EPBuddy was the pioneer of the first commercially available parallel board product, the ParaBoard. Since the original almost 2 years ago, he has introduced many alternate models offering different connectors and now smaller 4-port, safe versions. The model I received is the XT60, JST-XH V3 (safe) version.
This new V3 offers several new features and improvements over the previous models. Of course it employs polyfuses, the non-color changing type, to protect the board and balance leads from user mistakes such as connecting dissimilar cell count packs or packs with vastly different charge states. Additionally, 40A automotive type fuses have been placed between the main discharge lead connections to prevent damage to the board and battery from massive current flow between different packs. Lastly for the fuse protection, there is a 50A fuse on the input leads. I don't see the need for this fuse but I suppose it can't hurt to have it there.
Here is the board. It is smaller than the original ParaBoard and blue!
Note: The plastic housing on the balance lead in the right pic is an
AB Clip, a handy little accessory for JST-XH balance leads.
The V3 boards have connections on the end to allow "chaining" boards together. This could be helpful to people with different main or balance connectors on similar batteries they would like to charge in parallel. This will also make the "hyper-parallel-charging hobbyist" happy, you know the guy whole like to see just how many packs he can charge at once ;) The last new addition to the boards is an LED to indicate a pack is plugged in "correctly". The LED is connected between the 1st and 2nd balance port pins (cell 1) and so anytime there is a pack plugged in, it will light up. I am not sure how this shows that a pack is connected correctly, aside from it being aligned properly in a balance port. Since JST-XH balance leads are keyed, there is really no way to plug them in wrong without forcing them into the wrong port. On boards with Hyperion balance ports, I can see this being much more useful. Of course once you get one correct pack plugged in and the light is on, the LED usefulness basically ends.
The top and bottom of the ParaBoard V3.
The design and build of the board is fairly solid. The layout is clean except for the 40A fuses being somewhat in the way of the XT60s. All solder joints are clean and everything feels very solid. The 40A fuses are only between the 4 XT60s, to protect against an overcurrent situation between packs, and are replaceable. Overall it is a very tidy package and I am very impressed with it.
I did test the polyfuses and they do indeed work as advertised. I used a 3s pack and 2 male-female wire leads to connect the pack voltage across one of the polyfuses. The only thing that happens is that the polyfuse gets hot. I measured it at 166F after leaving it plugged in for about 5sec. No damage was done, no bad smells, nothing. Just a hot polyfuse, the way it is supposed to work.
Testing the polyfuses.
Using the board I have 2 complaints. First the lack of color changing polyfuses is unfortunate. It would be nice to be able to see when you have a problem. Unfortunately do to the tidy design of the board, only 3 of the 7 fuses per set of ports is visible and so I understand why they were not used. Secondly the placement of the 40A fuses makes it difficult to get the main leads unplugged. I bent mine over some and that helped, and I can't think of a better layout without increasing the size of the board, so I will accept this small "flaw" in favor of the small size. Of course these are both small issues that I believe most people will easy accept.
In the end this new version of the ParaBoard is a welcome upgrade. The safe aspects will almost guaranty no more shorts, melted sockets, fried balance wires, etc. from mistakes by users. That alone makes it a nice piece. Add to that the smaller form factor, with only 4 ports, and I think it is just right.
EPBuddy's Micro ParaBoard
Along with the newest ParaBoard, EPBuddy also released what may be the first safe parallel charging board for micros, a 1s parallel board with both JST-PHR-2 (fits E-Flite's mCPx 2) and pico (fits many of the tiny E-Flite and Parkzone models) connectors on it.
This little guy is nicely designed and has a very nice feel to it. The base made from dense plastic that is milled to fit perfectly. and it adds weight to the board to make it feel solid. There is a polyfuse protecting each set of connectors from overcurrent situations and a surface mount led shows when a pack is plugged in. The leads are 20awg wire that is about 7.5in long terminated with 4mm bullets.
The new Micro ParaBoard.
The newest additions to the ParaBoard line-up at EPBuddy are both welcome and useful. The ParaBoard V3 offers a nice combination of safety and features that make it a worthy replacement for the original. And compared to most of the micro parallel board out there, the new Micro ParaBoard board is a gem. I say kudos to Dale for two very nice and useful products!