bss_rcu

I've been using NiMh on my 72MHz receivers. Now that I'm moving to 2.4 (Optima) I'm planning to use 6v and am very much interested in A123 6.6v/2003Mah packs from Hangtimes. CellPro looks like a great charger for A123s. However before I buy A123 pack there are few things where I'm confused (even after going through the FAQ at hangtimes and A123 for dummies thread at FG). Pls help... my queries are

1. What connectors should I chose on the 2300Mah A123 pack, given that I'm going to use Hitec receivers/HD switches and quite likely CellPro charger. I'm ok to remove the pack from airframe for charging.

2. Do I need balance tap? If yes, then what connector - Univ/CellPro
3. Does the CellPro provide cycle function? Do I need to do A123 pack cycling? I'm quite likely going to use this charger for cycling my existing 4.8v NiMh (which I plan to use on ignition) as well. Any other good charger recomendation for both A123 and NiMh (how about GTPOWERA6-D ?)

Thanks.

dirtybird

My Feedback: (5)

Use connectors compatible with Hitec and Celpro. Check with Hitec or Celpro.
BTW the low cost Celpro does not charge A123's.
You will not need to remove the A123's for charging.
A123"s do not need cycling. For receiver use they do not need a balance tap.
NIMH batterys are a poor choice for ignition. NICDs are better.

D.O.A.F.S.

The Cellpro 4s most definutely does charge A123's, and is as easy as it gets to use. I've been using them for almost 2 years with zero problems. Depending what brand engine your running (check with their tech guys) you can use the A123's on your ignition as well. I run DA engines (called DA support) , and they will handle the 6.6 volt A123's unregulated with no problems, again been doing for 2 years.

dirtybird

My Feedback: (5)

I was wrong about the Celpro 4 and A123.
Ignition systems were designed to run on 4.8v NICDs. Some may tolerate 6.6 volts but its not a good idea to use it unless the designer says its OK. It will cost you of it fries the ignition system. There is a DC to DC converter inside of the ignition system. An extra volt or two on the input could mean several hundred extra volts applied to the primary of the spark coil. That could fry your transistors in there.
NICDs have plenty of capacity and you don't need a special charger.
A123's are a great battery, but until ignitions are designed for their use, I plan to use NICDs

Mikecam

Look at the hangtime site again. If your running Futaba gear like me then you can charge and balance right thru the charge jacks. All you need to do is remove the signal wire (white one)from the plug going to the receiver. The cellpro 4 does not cycle but if you have a charger that does discharge nicd/nimh then you can use it to discharge the A123 (1 amp discharge with 2 volt per cell cutoff) and get a capacity #. A123 do not need cycling but you should cycle them to get a capacity number for testing purposes. I have a triton jr for discharging.

This is what you want if charger/balancing right thru the charge jack, it is what I ordered and have run for 2 years. Only one charge jack on the plane, plug in and hit charge and walk away, no need to remove, I don't. If you have JR gear then this won't work for you. Something to do with their binding procedure.

A123 2 cell 6.6v 2300 Series Rx or Ignition pack w/std univ balance celltap Node/Tap Connector Options: None (using 3 wire combo) Pack Connector Options: 20g 3 Wire Combo Univ

bss_rcu

I'll go through hangtimes again. I'm using all Hitec gear... (A9+optima; servos are Hitec and Futaba).
all I use now are wall charger, so was thinking of avoiding buying multiple charger and buy only CellPro4. I'll check hangtimes and get the exact connectors that I think should serve the purpose... will get opinion here again with the selection.

Thanks.

bss_rcu

I thought NiMh would be atleast as good as NiCd. Any reason why to prefer NiCd over NiMh for ignition?

dirtybird

My Feedback: (5)

During the charge cycle of the ignition system it will draw a high current. It could be several amps. NIMH batteries have a higher internal resistance than NICDs. This could result in lower voltage charging of the ignition system and can cause missing at higher RPM's.
You may not have a problem. It depends on the ignition system and your use of the system.

bss_rcu

Finally I got my batteries and FMA cellpro charger from hangtimes after long wait with custom clearance. The battery that I got is -

A123 2 cell 6.6v 2300 Series Rx or Ignition pack
Charge Node/Tap Connector Options: 22g Univ
Pack Power Feed Conncector Options: 20g 3 Wire Combo Univ


And now I'm confused on connectors/wires. This battery has two connectors (univ), both with 3 wires (one with orange/red/black and other with white/red/black). I'm confused which is cell tap and which is power feed to Rx/switch. Since both connectors are with 3 wires I'm tending to think that I can use either of them for power feed (can't find visual diff between 22g and 20g wires) and can use either of them for balance charging the pack. Any idea on identifying the wire would be great help.

Also, I don't think FMA cellpro has discharge facility; what can a cheaper way of discharging the batteries safely (not below 2v/cell).

JoeAirPort

My Feedback: (41)

One plug should be soldered to the center tap inside the battery pack. The other one shouldn't. So even though you have three wires on each plug, only one should have the white or orange soldered to the battery balance tap. You can probe the plug ends with a volt meter. Only one should show approx. 3.3V and 6.6V, that's the balance plug. The other should only be 6.6V (black/red). The one with 6.6V only goes to the Rx/switch. Make sure you don't have both plugs as cell taps. If you do (I doubt it) you would need to clip the white or orange wire on the switch going to the rx. IMO Hangtimes should have labeled which one is which. I would have. Are you sure they didn't include instructions?

The best way to discharge is to use a charger that does a discharge cycle for 5-cell Nimh. Then you can program the charger to stop the discharge at 1.1 per cell, or 5.5 volts. Another low budget way is to use some lights for automotive as a battery load (0.5 to 1 amp) and monitor the voltage with a volt meter. Stop dicharging at 5.5 volts. 5V is ok too.

bss_rcu

This helped! Thank you very much! I charged the battery last night. I like cellpro :-)

HunkaJunk

I can say no matter what connecter you go with that the A123's can be charged pretty hard, so be sure and limit your charge rate based on the wire size and connector, I use a seperate charge lead and a balance tap so I can charge them real fast.

?? I only get a max 500-600 ma drain on any of my ignition modules, no zenoah modules but my ZDZ, Evolution, Fuji, CH, and RCexl, ignition modules all draw less that 1/2 amp at all times. I don't even own a NiCD pack anymore.

JoeAirPort

My Feedback: (41)

You're talking average contiuous power, he's talking about the large spikes of discharge current that an ignition draws. You'd need a high dollar oscilloscope to see these spikes. Anyway, most of us are fine with a strong/high discharge 4-cell NiMh. That's what I use. 1500 Elite cells.

HunkaJunk

I have a Fluke scope but I never thought of checking the power to an EI unit, maybe I'll bring it home from work someday if I get bored. 

JoeAirPort

My Feedback: (41)

I would def like to see your results. I don't think I've ever seen it on the forums.