single a123 for ignition unit
11-06-2008, 06:02 AM
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single a123 for ignition unit
Found this voltage stepup unit for sale in Hobby city. Done some tests and it supplies about 5v to a max of 1.5amps. I tested it to work down to 2.75v.with my rcexl system. With a single A123 rated at 3.3volts, a 2300mah batt would work very well powering an ignition unit safely and with minimal weight. I tried and and found the spark to be good even at minimum voltage.
I'll run some tests but so far I'm quite happy with the results.Finally a quick recharge at the field without worry.
I'll run some tests but so far I'm quite happy with the results.Finally a quick recharge at the field without worry.
11-06-2008, 07:15 PM
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RE: single a123 for ignition unit
I to found the RCexcl ignition to work well at low voltage. (1xLiPo)
On LiPo, the ignition gives ample warning of low battery voltage danger zone. The discharge curve of A123 cells is different though, so I do not think there is as much time for landing with this cell.
On LiPo, the ignition gives ample warning of low battery voltage danger zone. The discharge curve of A123 cells is different though, so I do not think there is as much time for landing with this cell.
11-07-2008, 09:19 PM
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RE: single a123 for ignition unit
Has anybody been running A123's unregulated on an RCexel ignition?? Mine has a 6 volt etched in the back so I am going to try tomorrow.
11-07-2008, 09:33 PM
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RE: single a123 for ignition unit
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
11-07-2008, 09:41 PM
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RE: single a123 for ignition unit
An added bonus of running lower voltage is the current draw also drops, so the ignition actually runs LONGER in addition to halving the weight of the ignition pack. The RCEXL ignition will fire right on down to a bit over 2 volts without missing. Test results here: http://www.ch-ignitions.com/tech.html#pwr
11-07-2008, 10:10 PM
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RE: single a123 for ignition unit
ORIGINAL: tkilwein
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
I ran my ignition on A123 2300mah, and powered my radio with it at the same time. I read it works on GHz, and I did it on my Futaba 9c using PCM by accident, my ignition battery was dead so I just took one of the radio's power leads and plugged it in so I could tune my engine, then forgot and flew it that way. I didn't see any glitches, but it's one of my favorite planes so I didn't risk it again. I plan on doing it intentionally in a junker.
11-08-2008, 08:51 AM
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RE: single a123 for ignition unit
ORIGINAL: soarrich
I pretty sure these are not the Nano Phosphate that the 2300 mah are.
I ran my ignition on A123 2300mah, and powered my radio with it at the same time. I read it works on GHz, and I did it on my Futaba 9c using PCM by accident, my ignition battery was dead so I just took one of the radio's power leads and plugged it in so I could tune my engine, then forgot and flew it that way. I didn't see any glitches, but it's one of my favorite planes so I didn't risk it again. I plan on doing it intentionally in a junker.
ORIGINAL: tkilwein
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
I ran my ignition on A123 2300mah, and powered my radio with it at the same time. I read it works on GHz, and I did it on my Futaba 9c using PCM by accident, my ignition battery was dead so I just took one of the radio's power leads and plugged it in so I could tune my engine, then forgot and flew it that way. I didn't see any glitches, but it's one of my favorite planes so I didn't risk it again. I plan on doing it intentionally in a junker.
11-08-2008, 09:42 AM
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RE: single a123 for ignition unit
ORIGINAL: soarrich
I pretty sure these are not the Nano Phosphate that the 2300 mah are.
I ran my ignition on A123 2300mah, and powered my radio with it at the same time. I read it works on GHz, and I did it on my Futaba 9c using PCM by accident, my ignition battery was dead so I just took one of the radio's power leads and plugged it in so I could tune my engine, then forgot and flew it that way. I didn't see any glitches, but it's one of my favorite planes so I didn't risk it again. I plan on doing it intentionally in a junker.
ORIGINAL: tkilwein
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
If you want even less weight go with the A123 1100mah version. I bought some VPX drill batteries using them and they cycle to ~900-950mah.
I ran my ignition on A123 2300mah, and powered my radio with it at the same time. I read it works on GHz, and I did it on my Futaba 9c using PCM by accident, my ignition battery was dead so I just took one of the radio's power leads and plugged it in so I could tune my engine, then forgot and flew it that way. I didn't see any glitches, but it's one of my favorite planes so I didn't risk it again. I plan on doing it intentionally in a junker.
The ones I have are nano phosphates by a123
11-08-2008, 12:53 PM
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RE: single a123 for ignition unit
VPX cells are definitely A123 Systems cells. I use them in smaller electric planes and they are very useful.
I found the Black and Decker Outlet stores sell the packs at 5 for $50, any day, not a special sale.
I found the Black and Decker Outlet stores sell the packs at 5 for $50, any day, not a special sale.
11-09-2008, 06:36 AM
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RE: single a123 for ignition unit
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
11-09-2008, 06:56 AM
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RE: single a123 for ignition unit
ORIGINAL: liquid_TR
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
11-11-2008, 07:27 PM
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RE: single a123 for ignition unit
ORIGINAL: liquid_TR
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
CR
11-11-2008, 07:44 PM
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RE: single a123 for ignition unit
ORIGINAL: Charley
Li is Lithium, Fe is Iron, Po4 is a phosphate; So they're Lithium Iron Phosphate. Is that what A123s are?
CR
ORIGINAL: liquid_TR
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
Erm no; if you look at the picture you will see they are Not Lithium Polymer. They are LiFePo4, which I guess is "nano phosphate" cells.
CR
11-12-2008, 12:34 AM
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RE: single a123 for ignition unit
Well, I put twelve flights on my A123's with no regulator on an rcexel ignition v-2. So far so good.
The difference between nano and non nano 123 batteries, as I understand it simplistically, is the nano are capable of higher burst and discharge rates. Whether nano or non nano Li fe, all should work for an ignition and are probably insignificant in difference when it come to a flight pack too. Not much difference between 30 amp or 60++ amp discharge rate when it come to my airplanes.
The difference between nano and non nano 123 batteries, as I understand it simplistically, is the nano are capable of higher burst and discharge rates. Whether nano or non nano Li fe, all should work for an ignition and are probably insignificant in difference when it come to a flight pack too. Not much difference between 30 amp or 60++ amp discharge rate when it come to my airplanes.
11-12-2008, 05:42 AM
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RE: single a123 for ignition unit
Hi terry, i tried to use the a123 hooked directly to the rcexl ignition V2 and it didn't work unless you're using 2s. Measured voltage was 3.34V without load. I think it needs to be in a fully charged state to work and registering higher than 3.3V
Anyway, I am quite happy so far with the results of the step up device which worked with the A123 very well and delivered a good 5.1v. The A123 settles down to 3.2~3.2V and holds it until its almost drained.Think I may go that route for some of my setups.I need further testing at WOT.
I used a li fe charger to charge these batts.A quick charge takes 15mins from fully drained!
pics-
Anyway, I am quite happy so far with the results of the step up device which worked with the A123 very well and delivered a good 5.1v. The A123 settles down to 3.2~3.2V and holds it until its almost drained.Think I may go that route for some of my setups.I need further testing at WOT.
I used a li fe charger to charge these batts.A quick charge takes 15mins from fully drained!
pics-
11-12-2008, 11:36 AM
#20
RE: single a123 for ignition unit
I wonder where some of this info comes from
The 1100 and 2300 ma cells sold by DeWalt/Black n Decker (VPX) are same chemistry
use the same charger on either
As for low power input ignitions
Look at the logic when deciding how much battery power you need..
It takes MORE power to fire thru higher pressure in the combustion chamber.
These little engines typically have quite low cyl pressures so if the low output setups work, you are working with a low output engine. No secret there
if it will run on 80 oct fuel it is a low output engine. I don't care what power is claimed .
When testing for performance , test using a high output ignition too.
Just because the engine is not sputtering does not mean the spark is adequate.
High output ignitions do add performance in high output engines . some of these rehashed weed eaters are not high output so any spark will run em.
The 1100 and 2300 ma cells sold by DeWalt/Black n Decker (VPX) are same chemistry
use the same charger on either
As for low power input ignitions
Look at the logic when deciding how much battery power you need..
It takes MORE power to fire thru higher pressure in the combustion chamber.
These little engines typically have quite low cyl pressures so if the low output setups work, you are working with a low output engine. No secret there
if it will run on 80 oct fuel it is a low output engine. I don't care what power is claimed .
When testing for performance , test using a high output ignition too.
Just because the engine is not sputtering does not mean the spark is adequate.
High output ignitions do add performance in high output engines . some of these rehashed weed eaters are not high output so any spark will run em.
11-12-2008, 01:54 PM
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RE: single a123 for ignition unit
ORIGINAL: RTK
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. All of which do not matter for an ignition and are probably insignificant in a flight pack also.
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. All of which do not matter for an ignition and are probably insignificant in a flight pack also.
1) Research at the University of Texas (I think it was UT, but could have been another in Texas) developed the basic LiFeP04 battery design using a solid bar of iron phosphate as the cathode.
2) Further research at MIT realized the iron phosphate could be formed into a crystal-like series of micro-scale cylinders (which they call Nanophosphate), which increases the actual surface area of the cathode by an order of magnitude. Imagine the difference in surface area between a solid cylinder and a hollow cylinder (A=2*Pi*r^2 + 2*Pi*r*h for solid, vs 4*Pi*r^2 for hollow), then expand that increase by millions of millions of times as the the size of the actual tubes decreases. The final product is a TREMENDOUS increase in the actual surface area of the cathode.
The actual rate of reaction depends upon the number of molecules that are capable of reacting at any given time. Because the cathode of the A123 is significantly larger, a significantly larger number of individual molecules are capable of reacting at a given time. Because of this the cell can deliver a very high current at a high voltage. This is purely logical from my standpoint.
The potential of these two developments is so great that the two professors and one post-doctoral student at MIT who developed the nanophosphate cathode started their own company to bring these to market, and that company is A123 Systems. ONLY A123 Systems batteries (and officially licensed cells) have the nanophosphate cathode that makes the LiFePO4 work so well. They were so successful they purchased Enerland Batteries (think Flightpower, Polyquest, and other famous cells...) to be their manufacturer to keep up with the demand.
Other LiFePO4 cells are similar but cannot provide the high current at high voltage. Look for true A123 cells soon in all the hybrid cars to replace the NiMH cells currently used. Talk about a revolution...
OK, that is enough for today.
11-12-2008, 02:08 PM
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RE: single a123 for ignition unit
It takes MORE power to fire thru higher pressure in the combustion chamber.
10KV can jump thru a couple of centimeters creating an arc discharge. there would be not much of a difference between using a 6V pack or 3.7V pack. both will create a suitable arc if they were stepped up directly without loss. The main reason the ignition unit wouldnt work below 3-2V DC is the inverter side electronics are actually cant work with such low voltages. If the transistors were chosen to work with those low voltages, we wouldnt have any problems using a single nicd cell. This is my theory. I actually never opened up a chinese ignition unit.
11-12-2008, 02:59 PM
#23
RE: single a123 for ignition unit
ORIGINAL: RTK
Well, I put twelve flights on my A123's witn no regulator on an rcexel ignition v-2. So far so good.
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. Whether nano or non nano Li fe all should work for an ignition and are probably insignificant in difference when it come to a flight pack too. Not much difference between 30 amp or 60++ amp discharge rate when it come to my airplanes.
Well, I put twelve flights on my A123's witn no regulator on an rcexel ignition v-2. So far so good.
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. Whether nano or non nano Li fe all should work for an ignition and are probably insignificant in difference when it come to a flight pack too. Not much difference between 30 amp or 60++ amp discharge rate when it come to my airplanes.
11-12-2008, 03:24 PM
#24
RE: single a123 for ignition unit
ORIGINAL: liquid_TR
Well thats not really true, as the total coil turn ratio is probably around 1:4000 to actually turn 5V DC into AC and step it up to 20KV. (its actually made by first stepping up the 5V DC into a much higher potential AC by means of a small inverter in the ignition unit then stepping up that AC potential up to 20KV).
10KV can jump thru a couple of centimeters creating an arc discharge. there would be not much of a difference between using a 6V pack or 3.7V pack. both will create a suitable arc if they were stepped up directly without loss. The main reason the ignition unit wouldnt work below 3-2V DC is the inverter side electronics are actually cant work with such low voltages. If the transistors were chosen to work with those low voltages, we wouldnt have any problems using a single nicd cell. This is my theory. I actually never opened up a chinese ignition unit.
It takes MORE power to fire thru higher pressure in the combustion chamber.
10KV can jump thru a couple of centimeters creating an arc discharge. there would be not much of a difference between using a 6V pack or 3.7V pack. both will create a suitable arc if they were stepped up directly without loss. The main reason the ignition unit wouldnt work below 3-2V DC is the inverter side electronics are actually cant work with such low voltages. If the transistors were chosen to work with those low voltages, we wouldnt have any problems using a single nicd cell. This is my theory. I actually never opened up a chinese ignition unit.
BUT it always takes more power to fire thru higher pressures.
This is why extremely high output ignitions were developed -for competition engines.
Most applications in passenger cars etc., neded high voltage with little amps - The gap plus the pressure is the condition which must be met.
For those doubters -once apon a time Champion Spark plug sold spark plug cleaners which were used in service stations and the customer could clean their spark plugs with these devices
a feature was adjustable pressure in th chamber which would show if the plug still fired under high pressure
High pressure being upwards of 100PSI
Most cars of the period had cranking pressures of over 100 psi so that always bugged me -I guess they used a very weak spark in th Champion Spark Plug Cleaner.
11-12-2008, 03:27 PM
#25
RE: single a123 for ignition unit
ORIGINAL: BTerry
There are TWO major developments in this battery design:
1) Research at the University of Texas (I think it was UT, but could have been another in Texas) developed the basic LiFeP04 battery design using a solid bar of iron phosphate as the cathode.
2) Further research at MIT realized the iron phosphate could be formed into a crystal-like series of micro-scale cylinders (which they call Nanophosphate), which increases the actual surface area of the cathode by an order of magnitude. Imagine the difference in surface area between a solid cylinder and a hollow cylinder (A=2*Pi*r^2 + 2*Pi*r*h for solid, vs 4*Pi*r^2 for hollow), then expand that increase by millions of millions of times as the the size of the actual tubes decreases. The final product is a TREMENDOUS increase in the actual surface area of the cathode.
The actual rate of reaction depends upon the number of molecules that are capable of reacting at any given time. Because the cathode of the A123 is significantly larger, a significantly larger number of individual molecules are capable of reacting at a given time. Because of this the cell can deliver a very high current at a high voltage. This is purely logical from my standpoint.
The potential of these two developments is so great that the two professors and one post-doctoral student at MIT who developed the nanophosphate cathode started their own company to bring these to market, and that company is A123 Systems. ONLY A123 Systems batteries (and officially licensed cells) have the nanophosphate cathode that makes the LiFePO4 work so well. They were so successful they purchased Enerland Batteries (think Flightpower, Polyquest, and other famous cells...) to be their manufacturer to keep up with the demand.
Other LiFePO4 cells are similar but cannot provide the high current at high voltage. Look for true A123 cells soon in all the hybrid cars to replace the NiMH cells currently used. Talk about a revolution...
OK, that is enough for today.
ORIGINAL: RTK
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. All of which do not matter for an ignition and are probably insignificant in a flight pack also.
The difference between nano and non nano 123 batteries, as I understand it, is the nano are capable of higher burst and discharge rates. All of which do not matter for an ignition and are probably insignificant in a flight pack also.
1) Research at the University of Texas (I think it was UT, but could have been another in Texas) developed the basic LiFeP04 battery design using a solid bar of iron phosphate as the cathode.
2) Further research at MIT realized the iron phosphate could be formed into a crystal-like series of micro-scale cylinders (which they call Nanophosphate), which increases the actual surface area of the cathode by an order of magnitude. Imagine the difference in surface area between a solid cylinder and a hollow cylinder (A=2*Pi*r^2 + 2*Pi*r*h for solid, vs 4*Pi*r^2 for hollow), then expand that increase by millions of millions of times as the the size of the actual tubes decreases. The final product is a TREMENDOUS increase in the actual surface area of the cathode.
The actual rate of reaction depends upon the number of molecules that are capable of reacting at any given time. Because the cathode of the A123 is significantly larger, a significantly larger number of individual molecules are capable of reacting at a given time. Because of this the cell can deliver a very high current at a high voltage. This is purely logical from my standpoint.
The potential of these two developments is so great that the two professors and one post-doctoral student at MIT who developed the nanophosphate cathode started their own company to bring these to market, and that company is A123 Systems. ONLY A123 Systems batteries (and officially licensed cells) have the nanophosphate cathode that makes the LiFePO4 work so well. They were so successful they purchased Enerland Batteries (think Flightpower, Polyquest, and other famous cells...) to be their manufacturer to keep up with the demand.
Other LiFePO4 cells are similar but cannot provide the high current at high voltage. Look for true A123 cells soon in all the hybrid cars to replace the NiMH cells currently used. Talk about a revolution...
OK, that is enough for today.
I forget the full explanation which is wasted on me anyway as I am barely literate .
Still working on perfektin a kerosene operated guitar. (for use in Utah)