niteman

Hey Guys,

Fly Aeroworks Yak 50cc with 3 nimh packs, 2 on rx and 1 on ignition all through 3 MPI seperate charge port type switches (redundancy). Hoping someone who uses the Sirius Quad Charger can help me out. Can anyone confirm that the Sirius Quad Charger will work with 2 nimh rx packs plugged into the same rx?? (Rx Bus Common Ground)

Like to purchase the sirius quad, but only if I can charge through the 2 MPI switch charging ports and NOT have to remove the canopy and unplug 1 of the 2 rx batteries each time.

Appreciate the replies,

Dan

phjoker

My Feedback: (4)

I have A WH extra 300 50cc 2- 6.0v 2400 NIMH for the servos 2- 4.8v 1650 NIMH for the receiver and the ignition
and I use the quad chqarger with no problems. The only problem is the sirius chargers are out of stock everywhere.
I have had another one on order for the last 2 months and they told me the shipments had not arrived???

niteman

Thanks for the reply phjoker,

Had a nice conversation with George from Peak Electronics. He was extremely helpful and more than willing to answer all of my questions. However, George did indicate that there is a problem when using a common ground (RX BUS) and he does not recommend charging that way without some modification to your switch or unplugging one of the batteries to break the common ground.

I'm not an electric guy, but from what I understood (George please correct me if I misquote) the charger will detect only the 1 pack with the highest voltage and react to that pack, leaving the other pack unconditioned properly.

SOOO, looks like I'll either abandon the 2 packs and use 1 good conditioned rx pack (not my first choice), unplug one of the bat's ( areal pain in the ***) between flights, or attempt the switch mod george suggested.

He also explained that 2 batteries sharing the RX Bus used for redundancy is limited this way (or wont work at all ! ), dependent on the type of Battery faliure, may make matters worse.

I really want 2 Bat's plugged into 2 ports on the rx for max amp delivery and easy charging method between flights. Have to figure something out.

Dan

Josey Wales

My Feedback: (61)

There are lots of people that use 2 packs/2 switches with success....aside from a catastrophic short in one of the packs, it pretty bullet-proof...

Check out this site and read about parallel operation..lots of good info

http://www.rcbatteryclinic.com/

niteman

Hi Joe,

Thanks for the reply. I've Read Red's advice many times, good stuff. However, "redundancy" is in case of 1 rx pack failing (catastrophic failure), right ??

I think others, like me, have great success in delivering max usable power (amperage) to the rx with two direct connects etc..., but George at Peak Electronis who I would think has to know a thing or two about this topic seemed pretty sincere that as far as "redundancy" goes, it is very questionable at best if one of the rx packs fails could drag the whole sytem voltage down with it. You know, I recall a real informative technician at MPI I spoke with some time ago warned me that "redundancy" in this type of setup will not work no matter what type of short. Like I said, I am electronically challenged so I am not making any claim to be an expert, thats why I like Peak Electronis Products, there easy to use.

My main point of the post was to see if the quad charger can charge with a common ground between 2 packs and it can't properly according to George.

Appreciate all the advice.

Josey Wales

My Feedback: (61)

Yep..

BUT this is pretty rare..If you are checking your packs before AND after each flight the chances of that happening are pretty slim..Its more likely that a switch will fail before the pack..If you are really concerned about that SmartFly sells a Batshare device that will prevent the pack that failed from draining the second one...

http://www.smart-fly.com/Products/BatShare/batshare.htm

niteman

Wonder if the Batshare breaks the common ground ?? If so, I can add a Batshare and still use my current 2 Bat setup WITH a Sirius Quad Charger?? Could be sweet and not much add'l weight. [8D]What do you charge with?? Do you share a Common ground??
Thanks Joe.

Josey Wales

My Feedback: (61)

No it wont break the ground for charging.....What I do with mine is just unplug 1 pack from the RX if I want to charge both at the same time...my RX's are easy to get to so it takes only a second to unplug

niteman

Perhaps I'm just paranoid, but I really hate unplugging from the RX bus over and over, especially the battery port, aileron ok, but the Battery port ?? And removing the canopy bolts on the Yak over and over to do the same. Wanted to plug into the two switch charge jacks and forget it. Wanting my cake and eat it too !!

Thanks for sharing your thoughts, very much appreciated.

Josey Wales

My Feedback: (61)

I know what you mean....Honestly I dont need to do that very often...I can get 8 13 min flights on a single charge from my packs so I rarely need to quick charge...

niteman

What size batteries are you running ? NIMH? Those are great flight times between charges. I have all digital 5955's and the suck the life out with moderate 3D.

Josey Wales

My Feedback: (61)

1500 Intellect 6v packs from Hangtime Hobbies...2 6v on the rx and a 4.8v on the ignition...I have them in both my 50cc Yaks..all 5955's

niteman

Great Batteries, been mulling over going to them myself, maybe the best setup out there for nimh. Looks like I will. NOBS is all I use. Thanks Joe.

Got a favorite Charger for these puppies?

Josey Wales

My Feedback: (61)

I use an Accu-Cycle Elite for cycling and quick charging...for regular charging I just us an Ace SuperDigipulse..

niteman

Thought about using not 1 but 2 of these http://electrodynam.com/rc/EDR-108/index.shtml Battery backers with our same setup to break the ground. I don't know the weight of them. Probably nominal. But you could quick charge at the field and not have to remove the battery plug or canopy or anything for that matter. Might work have to call them.

kadet

My Feedback: (5)

You might want to take a look at this charger as a possible sub for the Sirius. This one has no common ground problems at all, and it has more functions. [link=http://www.hughesrc.com]SPECTRA 4[/link].

Josey Wales

My Feedback: (61)

Dan..what is the mod George was talking about to the switch ?

niteman

Hey Joe,

If memory serves me right (what little I have ), he spoke about making a modification to the nuetral (common) wire in the switch.

I am not exactly sure what he meant or how it would be configured. Best to give George a call, he seems like a great guy.

This matter of not being able to use the quad charger to charge both of my nimh bats at the field between flights straight through the charge ports on the mpi switches is a-bit dissapointing.

I like to top off between flights, especially since I've gone to all hs5955's, real amp suckers !!!

Happy 4th

Josey Wales

My Feedback: (61)

Yea I agree..the common ground issue can be a pain..I don't understand why most chargers aren't designed to eliminate this issue...I guess there must be a good reason though[8D]

Ive been looking at the Hughes Spectra..from reading the online manual it seems to have a lot of great features and no common ground issues either which is a big plus..just haven't heard too much about it though to drop 300$+ on it

niteman

Me too, I looked at that charger as well. I think the software in the quad is the best however for long term care of the batteries we use.

George told me the new quad chargers are the best ever with even more updates in the software based on some real recent break-thru's on understanding battery chemistry; its all over my head.

I have been speaking with the owner of electro dynamics corp about thier pow'r back'r unit http://electrodynam.com/rc/EDR-108/index.shtml.

Seems they would be willing to add another heavy duty jr lead to the "out" side of the module for a total of 2 in and 2 out so you get max amps to the reciever, bat failure protection, "AND" the ability to use the quad charger right thru the ports on the switches with no common ground issues !! best of both worlds, but you do have another component in the link.

Josey Wales

My Feedback: (61)

I looked at that too but the single lead to the rx defeats the whole purpose of having dual switches/batteries! [8D]

If they decide to offer a dual output unit I think it would be a good thing to have..not only will it eliminate the common ground but now you have eliminated the issue of a bad pack shorting out the second one! I would prolly get it if it had dual output leads..

niteman

Joe

The technician's name is Andy at EMI-give him a call, real nice guy. After we spoke at length about the unit and I explained my need to maximize the amp delivery from the 2 batteries (through 2 switches etc..) he said adding a second lead to the unit would not be a problem for me as a "custom" order. He asked if I would just make a note on the order, per our conversation. I thought about getting at least two or three made up for me.

He also said the idea made alot of sense and may consider as a standard for future units. Sharp guy when I spoke to him.

Josey Wales

My Feedback: (61)

Sounds good!

niteman

Only one question left to ask if you call Andy, is if there is a "free" current flow from each of the batteries through the unit and through the 2 leads out ?? or is there a restriction of some kind in EMI's components used to build the Back'r that will drop the usable amps under load with the 2 lead mod ??

If you find out please post the answer for all of us. That is the only question that needs answering, otherwise it a go for me too.

Josey Wales

My Feedback: (61)

will do!