A123 Batteries for Dummies.

[Kiwi]

My cordless dremel took a dump so I drilled the little darlings out. That was a great exercise in frustration as well.

But they are out, tested and waiting on my charger to arrive. I have a super secret special thing on the way but I can t say boo until it arrives but mate, it is one cool setup.

[Pale Rider]

cool! I got mine on the Cellpro now..

[psk560]

I used a center punch and hammer to punch the little nipple down a bit and then used my normal torx driver to pull them out.

Another question...

I just put one lead w/balance on my two cell pack. Is it ok to charge through the HD switch with this?

Craig

[hybris]

	Quote: Originally Posted by Kiwi
	OK I'm going to get thumped here for shilling but I think its worth the pain. I have probably more time and cash invested in dang power systems than any mortal man should ever have. Its the mad tinkerer blood I inherited from my father so I blame him. These A123 batteries are the best thing since sliced bread to come along in my humble opinion. As for twin battery systems and switches etc I really think the following setup is as good as it comes. Look at what it does for you with a 50cc to 85cc model. Uses 5-Cell NiCd/NiMH or A123 batteries only with NO REGULATOR Built-in BatShare for battery input protection or balanced discharge Filtered and regulated 5.0V power supply to the receiver Receivers can be end-loading or top-loading Eight servo channels LED indicators for servo and receiver power Full RF filtering of all signals in and out of unit Fully buffered signal line for each servo Long servo lead line matching Integrated Ignition Cutoff Operates with single optional Failsafe-switch Light weight, 1.9 oz (54g) Compact design, 2.6” x 3.5” For me the real big deal here is the single fail safe switch, no regulators, not a single thing between the battery packs and the servos. Clean, safe and very functional. Note please!!!! That this is NOT INTENDED for 40% sized models. Its aimed at the 25% to 33% sized kits that run seven or eight servos. The capacity of the plugs is 6 amps constant (3 amps x 2) and the plugs will handle 7 or more amps each in a spike or non extended load situation. That gives you something around 14 amps up your sleeve. The ignition kill is just a good bonus and gets rid of more wires and plugs that normally clutter up the insides of your plane. I am pedantic in my thoughts that most RCcrashes caused by electronics are a product of bad connections, poor battery management, loose cables or not so perfect installations. I stand to get flamed for that statement but it wont make me change my mind. One of the biggest benefits by far with this setup is you only run wires to your servos from this setup. Theres no switches, no regulators, no optical isolators, no nothing. Its simple and clean and easy to install and setup. And that gents means less chance for an error, loose pin etc etc and a dirt nap. Sorry to be a shill but I just feel its worth pushing something as good as this setup.

I would like to see a version with out a battshare or regulator for the receiver. I like to run 1 receiver pack in my 50cc planes and want the full 7 volts to my receiver (Spektrum). If the battshare doesn't weigh anything, then that can stay.

[Kiwi]

Hybris,

Near my bed time mate but I will try to explain just a wee bit on those two points of yours.

No reg for the Rx:

The problem with that is it pretty much defeats one of the key benefits of the PEX system or any other power system for that matter. The regulated power supply to the RX is fundamental in ensuring a glitch free servo operation. If you expose the Rx to the voltage variations while the model is flying the servo sees the variation in voltage as a pulse width variation. So the servo bumps, squeals or in the worst case gets the jitters. Variable voltage to a receiver is just plain not cool. I understand your point with the Spektrum issue but that by the way is another problem

No Batt Share system.

Sure you can do with out it but if you get two battery packs with a different discharge curve the pack with the lowest internal resistance will continue to take the load. Effectively if you have seriously different packs you can end up with one pack taking all the load and therefore your C disharge capacity will only be as good as the one pack. The shared battery system would really be better named battery balancer which we now do as a routine thing every time we charge our packs. Two batteries that are balanced will share the load 100% where as tow unbalanced packs are only as good as the pack taking the load and that could be 50% of the capability of two packs working together.

[XJet]

	Quote: Originally Posted by Kiwi
	Hybris, No reg for the Rx: The problem with that is it pretty much defeats one of the key benefits of the PEX system or any other power system for that matter. The regulated power supply to the RX is fundamental in ensuring a glitch free servo operation. If you expose the Rx to the voltage variations while the model is flying the servo sees the variation in voltage as a pulse width variation.

That's plain wrong.

The receiver will only be affected if the voltage drops *below* the internally regulated voltage minus the minumum drop-out voltage of the regulator itself.

So if the receiver runs on 3.3V (not uncommon) and the regulator has a dropout of (say) 1.1V (again, not uncommon) then you can feed it *any* voltage between 4.4V and the full voltage of your battery without any effect on the output pulses it generates.

However, if you feed it with less than 4.4V there *will* be a problem -- so the simplest solution is a low-forward-drop diode (a Schotky type) and a large capacitor to provide the receiver voltage.

Ultra-reliable (not much to go wrong) and ultra-effective. Use a large enough capacitor and the receiver will continue to operate for 10 seconds or more without *any* voltage coming from the battery.

Why complicate things and reduce the safety margin by using a regulator where one neither necessary nor desirable?

[madmax]

BTW, saw a video today about Ford's new electric concept car, the "Volt". They are utilizing A123 batteries for power. Amazing stuff. Big potential in this space...

[Kiwi]

Bruce,

Thats all fine in theory and you know way more than me about this stuff for sure, but how if your description is absolutely perfectly correct do you explain servos and control surfaces glitching and farting all over the place on a freshly charged pack. If the internal voltage regulator is in fact delivering a stable voltage throughout the life of the pack why does this happen.

Again I admit to only have very limited knowledge on the goings on inside that black plastic case. This is not my specialty and what I have learned so far comes from guys like you so apologies to all if I am wrong.

[Kiwi]

	Quote: Originally Posted by madmax
	BTW, saw a video today about Ford's new electric concept car, the "Volt". They are utilizing A123 batteries for power. Amazing stuff. Big potential in this space...

General Motors old chap, Henry would turn over in his grave if he heard you referring to his old car company as GM.

[klhoard]

	Quote: Originally Posted by Kiwi
	Bruce, Thats all fine in theory and you know way more than me about this stuff for sure, but how if your description is absolutely perfectly correct do you explain servos and control surfaces glitching and farting all over the place on a freshly charged pack. If the internal voltage regulator is in fact delivering a stable voltage throughout the life of the pack why does this happen. Again I admit to only have very limited knowledge on the goings on inside that black plastic case. This is not my specialty and what I have learned so far comes from guys like you so apologies to all if I am wrong.

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The problem with high voltage from a fresh pack is with the electronics in the servo, not the receiver. . . .
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Check out these servos: http://www.fmadirect.com/products.htm?cat=46&nid=12 , they can handle up to 12.6 volts . . .
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[XJet]

	Quote: Originally Posted by klhoard
	. . The problem with high voltage from a fresh pack is with the electronics in the servo, not the receiver. .

Correct. You saved me saying the same thing.

[Kiwi]

Rapidly putting my foot back in the mouth where it belongs guys.

[Pale Rider]

Flew on the A123's today...all I can saw is WOW!! Flew 4 13 min flights and only used 20% of the pack..voltages started at 6.95--6.73--6.69--6.64...took less than 10 min to charge back up to full...I wired the pack up with dual leads to go into my 2 switches and lost about 4oz's over my original setup!

[klhoard]

	Quote: Originally Posted by Pale Rider
	Flew on the A123's today...all I can saw is WOW!! Flew 4 13 min flights and only used 20% of the pack..voltages started at 6.95--6.73--6.69--6.64...took less than 10 min to charge back up to full...I wired the pack up with dual leads to go into my 2 switches and lost about 4oz's over my original setup!

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What size plane are you flying them in? What was your original setup?
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[Pale Rider]

50cc Extreme Flight Yak..5955's..I was using dual 1500 Intellect nimh packs from Hangtime Hobbies