So, my buddy calls me up and asks me why I recommended that he purchase the switch/charge accessories package for his PE Pro. I asked him why not, and he said that he talked to you guys and you told him that he cannot charge the batteries through the charge port??? Is this true?
I understand that the smartswitch/charge port set up is not for use with regulated li-ions. But a guy with unregulated Nimh's, for example, should be able to charge his batteries through the charge ports, even at the same time, right? I am logically assuming so, because it doesn't say otherwise in your instructions. It also says nothing about not being able to use peak-detection chargers, either, so I assume peak chargers are OK, too?
Please clarify this for me and I will forward your response to my buddy. He is an older fellow and doesn't do this forum stuff...
Thanks in advance!

16 views and no answer? Anyone who has successfully charged batteries through the charge port on any of the Smart-fly power expanders can feel free to answer. I don't use the charge ports with my setup, so I don't have experience with it.

Bodywerks.

I am on my way to the office right now and will test it out ASAP.

But I', darned positive that if your using an unregulated power supply then you can charge without any drama. The reason I say that is I have used the Chg port to hook up a voltmeter so I dont see how it cannot work.

But let me see mate.

Hi Bodywerks,
I am not sure what your friend is talking about. If he called here I would have told him that you can charge both batteries at once using the charge ports IF your chargers can handle a "common ground" power system. What this means is that both batteries have their grounds connected. This happens any time you tie two batteries to a common point, even through mechanical switches, as switches do not switch the ground lead, only the power lead. Most chargers out there cannot handle a common ground system so you need to break the ground connection somehow. Please let me know if you need more explination.

Bodywerks.

Kiwi using someone else's login.

I just tried it and it works like a charm. As Bob said above the common ground issue can be a PITA and in the attached picture even though that charger can do two packs at the same time it cannot handle them both being connected to the PEX at the same time. that's a charger issue however and not the PEX.

From memory if I use two separate chargers its not an issue

Okay, so I am totally familiar with the whole common ground thing, and can see how charging both batteries at the same time with a single multi-port charger can be an issue (if this is something that can cause damage to anything, it really should be mentioned in the instructions, though). But if you have a charger, any charger, and want to charge one battery at a time, can you do so - not knowing whether or not you have a ground-sensing charger, and without unplugging the other battery??
Kiwi, in your pic, you only have one battery connected to the power expander. Could you still be charging that battery if you had another battery plugged into the other Dean's connection on the power expander? This is what I want to know.
While I understand that it would be by no fault of Smart-fly, if "all the stars need to be aligned on a full moon" or whatever to be able to charge through the charge ports, and if

Most chargers out there cannot handle a common ground system

, then it should be clarified in the instructions, IMO.

Hi Bodywerks,
The common ground problem has been around a very long time, anyone that has ever used two batteries with a receiver has run into this. We did not feel it was necessary to hit people over the head with warnings. Most people "should" be familiar with it now. You CAN charge one battery at a time even with both batteries connected. You CANNOT charge both batteries at once with a single dual-output charger or two separate chargers if they cannot handle the common ground system. These are rules. I can get technical on why these are the rules if you like. Let me know.

Thank you, that makes sense and still makes the charge ports quite useful. I am aware of the common ground thing, and I think he is, too, but he must have misunderstood you. In reality, he will likely only use it to check voltage between flights, but if he needs to do a field charge without removing the hatch he can, so long as it is one battery at a time.
Thanks again!

I know this is an old thread but it may see new action with the new HiTec X4 charger. The only chargers to my knowledge that you can use to charge 2 batteries at the same time through a Smartfly PE is the Ion Cube and the Cellpro. After reading the manual on the X4 it appears that this charger has the common ground issue. If not can someone elaborate on this topic? Also I think that substituting the ernst charge jacks for 2 high powered Fromeco switches( one switch for each pack)would still have the fail on capability and completely separating the batteries for charging with any multiport charger!! Does this sound right?

Originally Posted by ScottZ

The only chargers to my knowledge that you can use to charge 2 batteries at the same time through a Smartfly PE is the Ion Cube and the Cellpro.

CellPro does not work on a common ground system to my knowledge.

In this thread (post# 2115 at the bottom), the user has a 10S and has the common ground issue -->

https://www.flyinggiants.com/forums/...nd#post1312056

Do all of the "common ground" rules apply to any parallel system using Nickel batteries as well, whether it be a PE or just a system set up like the one in the attached image?

Yes. Same issue regardless of battery chemistry or component. The only way for the common ground to not be an issue is to physically disconnect one of the batteries from the system or get a charger that is insensitive to common grounds.