A123 packs

I recently ordered a few receiver packs from Pete that are 2300mah A123 2s1p. I installed the first one into my 50 sized Compass Models Knight 50 3D helicopter after having Duralite and Fromeco li-ion packs fail to last even a few months. I must say, I am pleasantly surprised by the fast charging these cells can take. I hit them with 9 amps via an Astroflight A123 charger. I get three flights in then charge in 12 minutes!

Next, I used the same 2 cell configuration to power my 5 year old daughter's Multiplex Easystar glider/trainer. This has an Align Trex outrunner brushless motor spinning a 6x4 prop. I was able to fly for 50 minutes of constant powered flight. With only two cells the vertical climb was about 70 degrees. At cruising speed my Whatt meter shows about a 2.5 amp draw. I landed after 50 minutes because the transmitter battery died! I pulled the pack and found it to be ambient temperature. The astroflight charger slapped 1900mah back into the pack in 12 minutes. After it peaked, the pack was barely warm.

I also bought a 4 cell pack to try in a Quique Somenzini 49" Yak, but the plan is still on the building table. I'll report back when I have some experience with that configuration.

At this point I am extremely impressed with these cells. I am anxious to see how a four cell 1100mah pack would work in a 400 class helicopter like the Cypher 3D.

Pete was a pleasure to talk to on the phone.

I plan to do more business with them soon.

Tyler

I have to sign the praises of these A123 packs as well. Although I haven't purchased the batteries from Pete and Elene I have the power tubes and they work fantastic.

The little extra weight of these packs compared to the Lipo pack doesn't seem to make a difference. I always use a little larger motor than what is suggested and things work great.

I am looking forward to getting the tube for the 1100mah cells.

Thanks for all the help!

Rodney

Well,

First, congratulations for this forum !!!
I came to A123's one year ago because I was affraid with Lipo's. I have two 10S1P packs for my E-Raptor E620SE, one 4S1P for my Walkera 60B, and I'm building an AIRWOLF / T-REX 600 which will be powered by A123 too.
A123 cells are perfect !!! I just finish to fly and immediatly charge the pack, while I put the second one in the heli to fly again: no need to wait the pack is cold (it's already cold after 8' of flight), and I put 6A of charging current (my charger is a BANTAM E-station 902 with PB6 balancers). The charge is so fast !!!
An other big advantage is you finally no need to balance them often: I build my packs by myself with the excellent SPT kits, but add balancing plugs. The 2 packs I've built are made from DEWALT packs, but they're soldered, so you have to unmount the cells, remove the soldering points, so it's long and fastidious. These packs need to be balanced every charge. But as I make a lot of advertising for MEC products (hello Elen & Pete ), I've finally convainced a friend to buy a 10S1P for his heli. As he doesn't understand elecricity (I think he's affraid by short circuits), he asked me to build the pack. You know what? the 10 cells He bought are perfectly balanced!!! after a cycle of 3 charges and discharge at 5A, there is only 0.01v of difference between all the cells WITHOUT BALANCING !!!
Now, you can hurt them, over charge them, shorten them, you don't risk anything... no explosion, no fire, no toxic smoke...
When I've opened my first Dewalt pack, I made a short circuit between the first and the last cell... believe me, I saw the biggest flash of my life, but if one cell was dead (there where a hole in the cell), the other ones were ok. I've done some tests on a cell someone gave me here in france, and I've been really bad with it. I've finally destroyed it by discharging it too much. The voltage came below 2 volts and it didn't appreciate: It became warm, was impossible to charge again, then the voltage came to 0v...finished.
To finish, the A123 cells are the most safe cells avalaible for our models,easy to use ( especially with SPT kits ),and Elene and Pete are really nice and are very helpful.

Thanks for all

Sylvain - France

I am currently using A123 2300 in my fleet biplane. I have averaged about 7-8 minutes per flight. I have noticed the power drops off fairly quickly with these cells once they are depleted. I am recharging using an Astrofight 110 Deluxe and the Daptor. This setup works great. I do wonder though if I am discharging the cells too far down as the Dapter always detects 5 out of the 6 cells when recharging. I have to manually select the 6 cell charge rate on the Dapter. I am looking towards getting some extended flight time by using a second 2300 pack with the parallel jumper that MEC offers. Can anyone comment on using this type of setup. Alas the cells are not availalble in a built up solderless tube right now. Hope they become available again. I really like the way these charge and perform without the added worry of safety issues that Lipos have.

Hi,

I had to give up an ASTRO "smart" charger because it too did not find the correct cell count for charging a 10-cell pack.

But I have been using (2) 10-cell A123 packs for about a year, flying them until I can barely sustain a low-hover at FULL THROTTLE (so, I'd say I am depleting them for all their worth!)

And I charge 'em back up (at 4 amps) and go off again. I get 2 flights on each pack every weekend and I have not noticed anything unsavory while doing this.

I think you're probably fine with your usage and charge-up scheme.

tob

Not too many new post on this forum. I wonder if it will continue? It looks like I won't be buying a parajump from MEC since they are closed for business. They don't look to complicated to make. Anyone made one themselves and have any tips on how they are assemble?