RJConnet

I tend to be a little like that the proverbial guy from Missouri, you gotta show me. Anyway, I've been reading all this stuff about the A123 batteries for a while now and when I started having a little trouble with the NiMH batteries in my EF 74" Yak I decided to try the A123 battery. I bought a 2 cell battery from Radical RC with a JR/Hitec plug on the power lead and the same plug on the balance lead. I charged it up using my LN 5014 on the NiCd setting at 2 Amps Watching the voltage at the balance plug. When it reached 7.4 volts I terminated the charge. I then discharged it still on the NiCd setting. Since the LN5014 is limited to 5 Watts on discharge the discharge current was about .75 Amps to .83 Amps. The output was 2000+ mAh, looked Ok to me so I charged it up again and then drained it down to 6.7 Volts (about 75 mAh). and strapped it into my plane and waited for the weather to clear. Three weeks later(last Saturday) I went out to the field fog or no and waited with several other guys for the fog to clear enough to fly. The battery still measured 6.7 Volts so I went ahead and got in 2 short (five to seven minute) flights before the fog closed in again and we had to go home.
After I got home I drained the battery to 6.0 Volts and found 1782 mAh remaining in the battery, needless to say I am sold. The MiMH batteries they replaced weighed 8.3 ounces and the A123 battery weighs 5.6 ounces. The only switch in the plane is the ignition switch, the power lead on the battery is plugged directly into the Rx through a short extension and the balance lead is plugged into an unused channel slot through a short two wire extension for a little redundancy. This is possible with the EF Yak because of the ease of removing the canopy for access to the battery and leads.
Sorry for getting a little long winded but thought someone might benefit from my experience.............RJ

jlkonn

My Feedback: (1)

Be careful...checking an A123 pack with a loaded voltmeter does not show the charge state of the pack.
Also, I'm curious about the balance tap plugged in to the receiver. Would this 3.6v or so to the power buss and
3.6v or so to the signal pin?
JLK

JustPlaneSweet

RJConnet,

Welcome to the A123 club! Get yourself an A123 capable charger and you have a no-brainer setup. I use a Cellpro 4 and charge through the standard JR style jack (the signal wire is on the center tap of the pack and does not connect to the receiver.) I charge between flights and before I am done refueling and BS with the boys, the packs are fully charged. I use B&D VPX packs in a 50cc Sig Sundancer.

Stan

Capt Lou

RJ:

I agree with JustPlaneSweet, get yourself a Cellpro 4S. I'm about 8 months ahead of you with the A123 battery packs and I won't buy anything else. The Cellpro is a real good charger. I re-charge my battery packs in 5-10 minutes for each pack and after 6 flights they are still at 80% capacity.

Capt Lou

RJConnet

JLK,
Thanks for your comment, I am aware of the problems with using a loaded voltmeter with the A123 batteries and am very careful. Also, if you will notice I said I am using a two wire extension to connect the balance connector to the Rx., only the common and +6.6 Volts are carried through to the Rx.

Stan and Cap't Lou,
I see that the Cellpro unit is widely accepted by those who have used it, it is on my short list...............RJ

Capt Lou

RJ:

Go to www.fmadirect.com to see the Cellpro product line. If money is not an issue, FMA just came out with a new charger, the Multi 4, and I have only heard good things about it.

Capt Lou

Capt Lou

RJ:

Go to www.fmadirect.com to see the entire Cellpro product line. If money is not an issue, FMA just came out with a new charger, the Multi 4, and I have only heard good things about it.

Capt Lou

AJsToyz

I just picked up my first < not my last > A123 pack, and it looks great so far ! I also purchased the Multi 4 charge , this makes this battery set up a no brainer. I received my pack 65% charged, plugged it in and started doing some cleaning. I heard a beeping a few minute later and it was topped off. I think the NiMH and the NiCD days are numbered.

Andy

Capt Lou

Guys:

I just received my Fly RC Magazine, Issue 65, April 2009, and on page 42 there is a rview of A123 battery packs. The article is very positive and confirms everything I have experienced in using them.

Capt Lou

TedMo

I have 3 123 packs that I had purchased some time ago with the intent of trying them, however none of them have node connectors wired to them therefore I'm unable to charge them useing my cell pro 10S charger. Any thoughts on what I can do? Since cells are aluminum can't solder wires to them?

jlkonn

My Feedback: (1)

Here's a drawing I made to send someone to check me out when I built a pack out of a VPX pack.
I didn't like the rapid, I mean really rapid voltage drop off near the end of the A123 capacity so I never
flew it. I know thousands do but I wasnt' convinced. Guess I'm just old fashioned. [sm=bananahead.gif]
Good luck!
JLK

Red Scholefield

My Feedback: (9)

I have tested the Multi 4 and its a winner at US $79.95.

Hangtime

My Feedback: (19)

Hi Red

Just got off the phone with Jamie, I'm bringing in the FMA Cellpro Multi-4's. Looks like an outstanding charger for just about anything. Big improvement in convenience having all cell technology support over the original 'lithium only' unit from what I've seen so far. Plus it's got PC connectivity and parameter programing capability.

Can't wait to get them in here and start playing with mine!

Capt Lou

RJ:

I see Steve at Hangtime responded. I have pruchased several 2300 mah A123 battery packs from Hangtime and I'm very pleased with them. They come pre-wired for balancing and are well constructed and wrapped. If you are still looking for a vendor, I recommed Hangtime. Delivery was prompt and, if needed, you can communicatte with them as to what you want to do with the pack.

Capt Lou

TedMo

I am a bit perplexed by what you state for chargeing the 123 packs. I have 3 packs as well as 4S charger but have not been able to charge them because do NOT have a balance node on them. Your method has me confused

AJsToyz

Ted,

When I purchased my charger they gave me a lead for the charger with no end for the pack. You can make your own lead to charge through the lead on the pack , it will not be balanced though.

Andy

RJConnet

I think what JPS is saying is that his pack or packs have a balance lead and connector which happens to be a JR/Hitec lead and connector. The yellow wire is normally used as the signal lead when used with a Rx and servo but when used as the balance lead on his pack it is the center tap on the battery pack. Since I don't have the 4s charger I don't know whether it will charge through the two lead power connector.........RJ

AJsToyz

Ok,

If thats the case, check FMA direct, they have a universal charge plug that might help. You should still be able to do a regular charge through the ground and positive lead, the signal lead would have to be the lower voltage.

http://www.fmadirect.com/detail.htm?...319&section=45

Andy