Originally Posted by aerobob

Okay.... so my stuff is on it's way. I will be using an FMA CellPro w/ balance to keep things on track. Will make packs using 20 ga, HD, 3 wire JR-style connectors/cables, using the orange wire for the "center tap" so the balance thingy works on 2S packs. Which, I have discovered, means the current crop of "charge switches" are history. They ONLY make/break the RED wire, with the orange and black wires tied through.

So - I'm thinking I'm in new territory here to permit in-plane charging, and that means "custom" switches which have mechanical redundancy and make/break both the red and orange wires. Which means finding 2A contact rating (or better) 4PDT slide switches that may meet mil spec.

ANYONE have any suggestions for this? Other than un-plugging the battery to recharge it (very inconvenient in my birds)....

I use Cermark "JR type" HD charge switches with no issues. I just disconnect the orange lead that goes into the receiver (I don't know what 3.5 volts on the signal line will do if anything). I do not know how good these switches are though. I am just using it on my 50cc plane and probably pulling less than 3 amps. For a good HD switch, I hope Smartfly or Fromco get on the ball to support A123.

I just had an idea about chargers. The fully charged voltage of a Lipoly cell is 4.2v, while an A123 cell is 3.6v, exactly 0.6v less, which is exactly the breakover voltage of a silicon rectifier (diode). I know my Accucycle Elite will charge through the protection diode of my transmitters, so maybe it can charge through a diode (or two, for two A123 cells). Program the charger for a 2 cell Lipo, and the final charge voltage should be correct. Hmmmm. I'll have to experiment with this when I get a chance.

Bob R.

I am working with the A123 batteries. I have learned from a friend that the Triton Chargers and the Hobbico chargers will not charge the batteries. You can get a charger from Horizon to charge the batteries but it is $99.99 for the charger. I found this company that sells what they call a "Dapter." You put it in line with your charger and batteries. I have inclosed the material on the web site below:
http://www.slkelectronics.com/lipodapter/index.htm
Newly Improved!
Dapter
(a.k.a. LiPoDapter+)

- handles DeWalt 36V (M1) cells
- handles A123 Systems (M1) cells
- adapts LiPo chargers for M1 cells
- still works with NiCad chargers
- handles up to 10 M1 cells
- handles up to 8 LiPo cells
- handles up to 8 amps


We introduced the LiPoDapter last year for use in charging Lithium Polymer (LiPo) packs. Those of us who had been heavily invested in NiCad and NiMH batteries over the years hated to let those $$$$ NiCad chargers gather dust as we ventured into the brave new LiPo world. LiPoDapter allowed most of these chargers to be used for LiPo without taking away their original function. Our LiPoDapter Tutorial gives a brief overview. Our LiPoDapter+ Instructions are available in PDF format.
The long-awaited DeWalt 36V cells have finally arrived. These cells were developed by A123 Systems and are commonly referred to as M1 cells. These cells require a significantly lower charging cutoff than ordinary lithium cells. The LiPoDapter electronics were redesigned in anticipation of the new cell technology but no cells were available for software development. As the new code was finally written, other changes were incorporated to enhance LiPoDapter capabilities. The new unit can charge up to ten M1 or eight LiPo cells. It can handle up to 8 amps to charge 8AH LiPo packs in an hour or M1 packs in less than twenty minutes. Of course, this is limited by your NiCad charger's current and voltage capability. As a point of reference, an Astro 110 Deluxe should provide full capability. LiPoDapter+ will also allow your LiPo charger to charge M1 cells if it can be set to a fixed cell count (fully automatic chargers such as the Astro 109 can get confused by M1 cells).
LiPoDapter+ has proven extremely popular for charging the new M1 cells. We are also tired of typing 'LiPoDapter+'. We are now calling this unit Dapter - fewer syllables, same capabilities.
We like to fly "40-size" planes that require higher cell counts. This is typically two 10-cell NiCad packs or two 3S LiPo packs. We combined two Dapters on one board and added switches so that we can charge two packs in series (separately monitored). The switches allow either Dapter to be used alone. In our applications (one pack also supplies BEC), one pack always is done before the other. The charger shuts off. We throw a switch and restart the charger, allowing the other pack to finish. Keeping two packs charging on one "old" charger eases the pain of the long LiPo charge times. The Dual Dapter can also charge M1 cells. It is limited to 6 cells per side but is rated for up to 8 amps. You can charge two 6-cell M1 packs in twenty minutes with an Astro 112 Deluxe or twenty-five minutes with a 112D.

Dapter charges 2S to 8S LiPo packs
Dapter charges 2S to 10S M1 packs
one LiPo cell for every three NiCads your charger can handle
one M1 cell for every 2.5 NiCads your charger can handle

Dapter typically gives 85-90% LiPo charge
Dapter typically gives 95% M1 charge
faster charging and longer battery life

Dapter charges at up to 8 amps

Dapter is only $39.95 including US shipping.
Dual Dapter is only $79.95 including US shipping.

Hop that this will help out

I use a Dapter great unit and inexpensive. I do my 4 cell power packs for my 3.4 lb electric planes perfect for this with a Astro 12 Deluxe charger

For a rx pack- (two cells ) ,the Cell Pro by FMADirect is a more handy package (and 70 bucks ) far better for ease of operation than the one from Horizon - sad to say -- look up FMADirect CellPro 4 (A123 )

Bob,
on the jack thing, here is my thought. I am going to build all my packs with heavy wires and a Deans. make em all the same with a center tap. capable of being used as primary on electrics too.

Then I will soldier what ever adapter need done. For balanced in plane charging using center tap, when I cut off the standard connector from the switch feed, just run the signal wire extension to the tap and connect. Then pull the signal wire from the switch output jacks. this gives 2s balanced at the switch so you can make a charging adaptor for you charger.

IF you do that though, One of the tecniqes from your website definitely applies here. It might be good to put a little extension on your AR7000 or 9000 battery plug for binding because DX users then cannot bind through the charging plug. easy tadeoff

Goose - I'm waiting for the FMA Cell Pro to arrive, so I can play, but after off line discussions with Dick, we've decided the setup for those using Spektrum receivers is simply that the ORANGE lead FROM the switch TO the RX must be removed/cut. That configuration will permit charging of the A123's using the charging jack, with orange wire wired as Dick has shown back some pages as the "center tap" on the two cell packs. Of course, this configuration means the "battery" connection on the RX cannot be the BIND receptacle any longer, so that has to be handled differently.

BTW - for those disassembling the DeWalt battery pack. Careful use of the thin Dremel Cutoff wheel permitted slotting of all the screws on the case, then just removed them with a normal small-blade screwdriver. I also didn't want to pry on the batteries to remove them, so I carefully used the Dremel to cut the corners on a long side of the pack, from the top to bottom, then just "folded" the long side open to get the batteries out. Sorry no pics.

And "Another" Charging solution.... again, between Dick and I talking through it. When building the Rx pack, wire in a three wire *additional* male battery pigtail. Brown to Neg, Red to Positive, Orange to center tap between cells, then mount that pigtail in one of those Ernst fuse connector housings.

This setup permits NOT modifying the three wire switches, and leaving the switch plugged into the Bind/Battery receptacle on the Rx.

When I do mine (hopefully start this weekend), I'll post some pics.

The real beauty of this setup?
You can't have a brain lapse and get lost trying to remember what wire / switch got modified and how it affect things like "binding" on the Spektrum.
It takes longer - sure and more wire but works with no hitches
Also -for those who care:
the A123 cells charge at a max of the rated voltage - so even if you did a dumb thumbs and started charging with the power switch still feeding to the rx from the battery , nothing is harmed from an overvoltage
( NiMh and NiCad use a higher voltage potential to charge but A123 uses only the peak voltage potential, 3.6V per cell.)

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One other important point to know when disassembling the DeWalt packs. . . the button is negative and the ENTIRE aluminum case is HOT POSITIVE!!
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Don't ask me how I found out. . . just leave the paper jackets on the batteries. .
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Here is just one example of what can be done with these cells.

http://www.a123racing.com:80/html/killacycle.html

Originally Posted by Boulder

Here is just one example of what can be done with these cells.

http://www.a123racing.com:80/html/killacycle.html

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Did you see the video of this bike doing a night run? At the end of the quarter mile a flaming chunk of the speed control came flying out.
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Originally Posted by klhoard

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Did you see the video of this bike doing a night run? At the end of the quarter mile a flaming chunk of the speed control came flying out.
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No, I missed that one, I'll have to check it out.

Has anyone just purchased them from A123? Does their charger work well?

Hypersonic™ Two 2S2P Starter Kit
AS400147-000--HS-SK-2S2P-2
Retail Price: $339.95 Two 2S2P Hypersonic™ 4600 6.6V packs and One Sonic Charge System
Dimensions: 135mm x 28mm x 53mm
Weight: 310g
Output: Up to 30C continuous, 60C pulses
Features: Balancing connector, Deans Ultra output/charge connector


??? Craig

sounds to me like the setup is worth about $100.00
but what with the setups some people buy - I will just say that you can purchase a whole pack of ten cells (EBay) buy a CellPro charger - sell the remaining 6 cells and spend a hell of a lot less - oh yeh and end up with a faaaaar better charger for doing receiver packs .

Originally Posted by klhoard

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Don't ask me how I found out. . . just leave the paper jackets on the batteries. .
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Keith,

How do you know