BarracudaHockey

My Feedback: (11)

Thought I'd share this.

WrongWayRC now has 2500 Mah genuine A123 cell 2 cell reciever packs in stock and I purchased one for my 50cc MSX-R.

He wired it up to my specs with heavy duty wires and a deans plug for my reciever and a servo plug for my ignition. In addition he now has 3 wire blance charge leads that plug directly into a cell pro. Couple that with an external charge jack and now I dont even have to pull the canopy to balance charge my A123's. I like these three lead charge harnesses better because I've had the pins on the balance board on my cell pro degrade after time when running 4 amp charge rates through them.

rmh

Nice setup - we make our onw A123 packs -but basically th same as you show -
I won't use the regulated 7.2 Lipo tho some of the pattern guys think they are somehow preferrable to a pair of A123
Can't see how -

Four Stroker

Dick; where do you get the A123 cells ? with tabs ?

rmh

I bought up a bunch of the 1100 batteries B&D sold for their little drill- which proved to be a dud in th market.
I solder to the shell or end as needed. I have a good 60 watt iron and solder /flux which makes a instant bond .

kenair

My Feedback: (10)

Is anyone using dual or parallel Life RX packs wires as shown by Red [link]http://www.hangtimes.com/parallel_packs.html[/link]


Do you charge both LiFe RX packs at the same time?

thanks -ken

pilotpete2

Yes, been doing it for the last 4 years with great results.
No, the common ground between the two batteries will be an issue with most chargers.
With the fast charging that A123's allow, topping off the two batteries separately hasn't been a problem for me.
Pete

BarracudaHockey

My Feedback: (11)

+1 ^^

ROBCAR

My Feedback: (52)

So Barracudahockey, Are you running a 50cc plane with only 1 2500mah battery and that one batt powers your servos and ignition? Only 2 cells for the entire plane? Are you running a battery eliminator for igniton?

BarracudaHockey

My Feedback: (11)

Yes
No
The battery has dual outputs, one goes to the reciever through a JR HD charge switch. The other goes to a switch, RC Excel ignition kill, then to a drop down diode then to the ignition.

ROBCAR

My Feedback: (52)

OK, I have a 100cc yak and I plan on running 2 a123 packs through 2 jr chargeswitches and will use a tech aero battery elim for the ign. I want to be able to re-charge through the jr chargeswitches though. Similar to the diagram up a few posts. Just not sure what wiring to get on my packs. I charge with a cellpro multi 4.

BuschBarber

My Feedback: (2)

With a 100cc size aircraft, why would you tap off one of the Rx batteries to power the Ignition. Another A123 for the Ignition is not going to add significant weight. These batteries charge so fast it should not be a big inconvenience to have to charge another battery.

ROBCAR

My Feedback: (52)

You dont "tap off" one of the batteries. It plugs into a open channel on the RX and and the other end to the ignition. Lots of giant scale guys using it with very good results.

BuschBarber

My Feedback: (2)

So the Tech Aero device draws power from the Receiver and also acts as an Electronic Kill Switch? If your receiver were to Brownout wouldn't that shut down your motor as well? Doesn't it put an extra load on your Rx batteries? I am just asking because I had not seen that product before. I have seen some use the Rx battery for both the Rx and the Ignition. In an aircraft that can handle the extra weight, I would feel safer with a separate Ignition battery and a FiberOptic Kill Switch.

ROBCAR

My Feedback: (52)

Watch this video from the beggining. It probably has more info than I can give you since I am new to this product myself. This is another version of it. There a a few companies that make one. It does get assigned to a channel on your radio and can be used as a kill switch.

http://www.troybuiltmodels.com/items/WRCIBEFV2.1.html

BuschBarber

My Feedback: (2)

Thanks!!

rmh

The larger SPEKTRUM/ JR rx have beefy pins and soldered lands - you can draw lots of current momentarily thru them but alas never more than 4 amps at a steady rate - the wire ends in the plastic housings melt.
so hook in the ignition wherever you like
as long as it all comes from same source - there is the same power losses seen by the rx and the same dirty information which MAY happen.
My Personal preferrence is to divorce ignition from radio - completely
makes trouble shooting much easier
I once saw a guy loose his plane because he had those old clamped caps on the spark plugs .
One got loose creating intermittant grounding and resultant high "noise" in the model
I Don't want any feedback in my systems .

BarracudaHockey

My Feedback: (11)

Actually my Pawnee is setup that way, and you're right, other than the convenience of only charging two batteries there's no other good reason.

Two batteries, one to the reciever, the other to the reciever and ignition.

The only reason I did it is so I would only need two batteries and two switches. Though the power safe reciever has a soft switch.

rlmcnii

My Feedback: (3)

ROBCAR,
Have the A123 packs wired with 3-wire JR pigtails. Use the signal wire (orange or white) as the balance wire for the pack. If the switch has a 3-wire output you must disable the signal wire (orange or white) going to the receiver so that the receiver does not get balance voltage in the signal wire. You may charge through the charge-port in the switches with an FMA connector mated to the 3-wire JR pigtail. FMA shows the wiring protocol on their website.
I have used this method very successfully with a Cell Pro charger.
There is one consideration that I do not fully grasp: That is that many switches, when open (turned off), only open the hot wire (red) and the ground remains closed. There is concern about the two separate packs sharing a common ground through the receiver. The problem with this shared common ground I do not understand.
My solution has always been to disconnect the pack that is being charged from the receiver by unplugging the switch output wire from the receiver. Perhaps such caution is totally unwarranted.
Illumination from those more knowledgeable is always welcome.

pilotpete2

The only issue with the common ground is in trying to charge both batteries at the same time. If you charge the batteries one at a time, no issue, and there's no need to unplug anything if you're only charging one at a time.
I've been balance charging my A123 receiver packs through the heavy duty switch/charge jack harnesses for the past four years. Y' just gotta remember to cut the signal wire in the lead from the switch to the receiver, or you'll have 3.3V going to the signal pin of the channel you're plugging into. You don't want that
I'll put in a plug for Radical here, when you order an A123 receiver pack from them, they have the option on the drop down list to have the battery built with a single 20awg servo lead with the signal wire connected to the batteries node. Perfect for those who want to balance charge through the charge jack!
Pete

ROBCAR

My Feedback: (52)

I thought with the switch turned off power from the charger only goes to the battery being charged. Maybe I am wrong. I have a cellpro multi 4 on order and can only charge one battery at a time anyway, Right? I just need the correct harness that goes from the cellpro directly to the jr chargeswitch in the side of the fuse. I will have to look at that option Radical rc has.

BuschBarber

My Feedback: (2)

For a normal Switch Harness, the Charge Jack is routed directly to the Rx battery when the Switch is Off. DSC compatible 3 wire Switch Harnesses have a 3rd wire going to the Rx so you can Bind a Spektrum Rx through the Charge Jack.

LiFe/A123 batteries charge through the Balance Tap, which is not connected to the Switch Harness.

ROBCAR

My Feedback: (52)

Maybe what I will do then is just use the switches for switches and not charging. I can get my packs made just the the first post of this thread and balance charge through another charge jack. The holes are already there from previous owner.

rlmcnii

My Feedback: (3)

ROBCAR,
You may charge the 123s through the port in the switch. You need three wires from the pack to the switch with the signal wire (orange or white) wired as a balance wire from the pack, The signal wire from the switch to the receiver must be cut or disabled. You must use a three-wire switch. You must obtain or make a charge cable that will mate the CellPro to a JR (or Futaba) three-wire pigtail which will fit the chargeport in the switch.
Pilotpete apparently answered my concern about a common ground through the receiver and my practice of disconnecting the output side of the switch from the receiver while charging has been not required.

http://www.usastore.revolectrix.com/...-10-5-Position is the connector required to make your own charge cable.

This: http://www.revolectrix.com/support_docs/item_1315.pdf is the wiring protocol.

AA5BY

Interesting discussion... can I ask a variant question? Can LiFe be regular charged a few cycles between balance charges? If so, mounting the batteries for fairly easy removal seems an option and doing the regular charging through the switch/charge. Follow up question if this is a reasonable management scheme... how many regular charges between balance charges?

Truckracer

My Feedback: (19)

I balance charge my A123 batteries about once a month and monitor the individual cells during the balance process. Rarely do I see any degree of imbalance but at least I know they are OK by going through the process.