Litho's pics: Double Stack (Safety issues?)
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greenLED
Flashaholic
Re: Litho\'s pics: Double Stack
Isn't mixing battery types/capacities dangerous?
Isn't mixing battery types/capacities dangerous?
jtice
Flashaholic
Re: Litho\'s pics: Double Stack
WHOOOOAAAAAA,,,, !!! /ubbthreads/images/graemlins/ooo.gif
you REALLY shouldnt be doing that !!!
Especially with lithium cells!!!!
They can EASILY burst open, or maybe even explode !!!
That makes me neverous just looking at it!
WHOOOOAAAAAA,,,, !!! /ubbthreads/images/graemlins/ooo.gif
you REALLY shouldnt be doing that !!!
Especially with lithium cells!!!!
They can EASILY burst open, or maybe even explode !!!
That makes me neverous just looking at it!
bwaites
Flashlight Enthusiast
Re: Litho\'s pics: Double Stack
Well---
This setup has been used, A LOT, without real problems. The chemistries are similar enough, and the AA's actually have a longer life than the 123's, so the light fades and the batteries have to be replaced before there is stress on the AA's and the AA's can't put enough juice out by themselves to cause a problem with the 123's. I would just be careful to let them sit for a few minutes before taking them out of the tube after running them down.
Bill
Well---
This setup has been used, A LOT, without real problems. The chemistries are similar enough, and the AA's actually have a longer life than the 123's, so the light fades and the batteries have to be replaced before there is stress on the AA's and the AA's can't put enough juice out by themselves to cause a problem with the 123's. I would just be careful to let them sit for a few minutes before taking them out of the tube after running them down.
Bill
litho123
Enlightened
Re: Litho\'s pics: Double Stack
Hello Everyone -
These pics were in reference to this thread
RE: using litho 123's and litho AA's together, I've read about this practice since I found the CPF forum back in the fall of 2003. I have not read any thread talking about any adverse effects caused of using them together.
I have used this combo to run the WA1274 on USED 2x3.5x123 to insanely bright levels (bulb life = 5 minutes to an 1 hour) as well as the WA1185 and Carley 809 on 2x4.5x123.
RE: the different batt chemistries...Li-Ion / nimh / nicad / lithium
I will NOT run two different batt chemistries together in the same light. I don't think that it is a smart move. I have NOT read about people doing it, nor will I be the first to try it.
Hello Everyone -
These pics were in reference to this thread
RE: using litho 123's and litho AA's together, I've read about this practice since I found the CPF forum back in the fall of 2003. I have not read any thread talking about any adverse effects caused of using them together.
I have used this combo to run the WA1274 on USED 2x3.5x123 to insanely bright levels (bulb life = 5 minutes to an 1 hour) as well as the WA1185 and Carley 809 on 2x4.5x123.
RE: the different batt chemistries...Li-Ion / nimh / nicad / lithium
I will NOT run two different batt chemistries together in the same light. I don't think that it is a smart move. I have NOT read about people doing it, nor will I be the first to try it.
HarryN
Flashlight Enthusiast
Re: Litho\'s pics: Double Stack
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
_______________
edited - I went back and looked at the Li AA capacity behavior and decided that this is probably an OK setup. I was thinking of the normal AA curves when I wrote this - sorry. I will comment below on the reverse diode - still a good idea.
______________________
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
(please ignore this part)
________________________
I would like to get the input of others, but personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA. Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
_______________
edited - I went back and looked at the Li AA capacity behavior and decided that this is probably an OK setup. I was thinking of the normal AA curves when I wrote this - sorry. I will comment below on the reverse diode - still a good idea.
______________________
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
(please ignore this part)
________________________
I would like to get the input of others, but personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA. Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
litho123
Enlightened
Re: Litho\'s pics: Double Stack
[ QUOTE ]
HarryN said:
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
[/ QUOTE ]
Thanks HarryN for your thoughts.
I certainly want to drive these bulbs safely. I stop using the batts at the first sign of noticable dimming. Could you explain further the drawbacks of using different capacity cells?
[ QUOTE ]
HarryN said:
... personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA.
[/ QUOTE ]
What makes AA NiMH setup different from Li AA?
[ QUOTE ]
HarryN said:
Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
[/ QUOTE ]
A single stack of 5x123 can't keep up with the current demand of the 1185. Doubling the stack (2x5x123) is well into instaflash territory, which is why the 2x4.5x123 has worked so nicely.
diodes / resisters / inductors ... guess I have some more things to read up on. Any links?
[ QUOTE ]
HarryN said:
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
[/ QUOTE ]
Thanks HarryN for your thoughts.
I certainly want to drive these bulbs safely. I stop using the batts at the first sign of noticable dimming. Could you explain further the drawbacks of using different capacity cells?
[ QUOTE ]
HarryN said:
... personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA.
[/ QUOTE ]
What makes AA NiMH setup different from Li AA?
[ QUOTE ]
HarryN said:
Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
[/ QUOTE ]
A single stack of 5x123 can't keep up with the current demand of the 1185. Doubling the stack (2x5x123) is well into instaflash territory, which is why the 2x4.5x123 has worked so nicely.
diodes / resisters / inductors ... guess I have some more things to read up on. Any links?
HarryN
Flashlight Enthusiast
Re: Litho\'s pics: Double Stack
[ QUOTE ]
litho123 said:
[ QUOTE ]
HarryN said:
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
[/ QUOTE ]
Thanks HarryN for your thoughts.
I certainly want to drive these bulbs safely. I stop using the batts at the first sign of noticable dimming. Could you explain further the drawbacks of using different capacity cells?
_____________
Hi - I did some checking using the plots from silverfox' tests of Alkaline and Li AA cells in Nov 2004, as well as his charts of various 123 cells. His AA cell charts only go up to 1 amp, but I was clearly wrong on the idea that this would drive the AA cells into reversal (at 1 amp). I was thinking of normal AA cells - sorry for the error.
__________________________
[ QUOTE ]
HarryN said:
... personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA.
[/ QUOTE ]
What makes AA NiMH setup different from Li AA?
________________
The logic behind this was that AA NiMH cells can handle high currents better than primary Li enhanced AA cells. If you are pulling over 2 amps per pack, I am not certain where you are with this setup, but 1 amp looks ok to me.
________________________
[ QUOTE ]
HarryN said:
Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
[/ QUOTE ]
A single stack of 5x123 can't keep up with the current demand of the 1185. Doubling the stack (2x5x123) is well into instaflash territory, which is why the 2x4.5x123 has worked so nicely.
diodes / resisters / inductors ... guess I have some more things to read up on. Any links?
[/ QUOTE ]
__________________
The idea behind the diodes comes from an EE that I asked to design something for me in the past that pulled from two battery packs - sort of like your setup. He agreed to do it under one condition - had to have reverse protection diodes to keep from sending one pack into reverse.
His logic is that batteries are never exactly alike, either in starting voltage, or voltage during use, so one pack might end up being a higher voltage than the other, causing reversal. He must have had a bad experience with it because it was his only "must have" in the whole project.
I am more used to LED light setups, where you burn off the slight excess voltage with a resistor or use a buck converter. I am just not used to seeing a mixed pack - prob ok - certainly interesting.
[ QUOTE ]
litho123 said:
[ QUOTE ]
HarryN said:
I think the historic concern is the fear of running the cell in reversal, essentially trying to charge a primary Li cell. If this happens to 123s, this is a known bad idea with demonstrated non-desired results.
My quick calculation of 123 vs AA Li capacity indicate that you are in fact driving the AA into reverse, and it is only the grace of the cell maker keeping you from an unhappy event.
[/ QUOTE ]
Thanks HarryN for your thoughts.
I certainly want to drive these bulbs safely. I stop using the batts at the first sign of noticable dimming. Could you explain further the drawbacks of using different capacity cells?
_____________
Hi - I did some checking using the plots from silverfox' tests of Alkaline and Li AA cells in Nov 2004, as well as his charts of various 123 cells. His AA cell charts only go up to 1 amp, but I was clearly wrong on the idea that this would drive the AA cells into reversal (at 1 amp). I was thinking of normal AA cells - sorry for the error.
__________________________
[ QUOTE ]
HarryN said:
... personally, I think a safer setup, but similar voltage, would be to use an AA NiMH instead of the Li AA.
[/ QUOTE ]
What makes AA NiMH setup different from Li AA?
________________
The logic behind this was that AA NiMH cells can handle high currents better than primary Li enhanced AA cells. If you are pulling over 2 amps per pack, I am not certain where you are with this setup, but 1 amp looks ok to me.
________________________
[ QUOTE ]
HarryN said:
Even better, would be
- 5 x 123
- A protection diode to prevent reverse current on each pack
- A 1 or 2 ohm resistor to drop the voltage to the desired level.
- A fanatic would add an in line inductor to dampen the turn on surge.
Just MHO.
[/ QUOTE ]
A single stack of 5x123 can't keep up with the current demand of the 1185. Doubling the stack (2x5x123) is well into instaflash territory, which is why the 2x4.5x123 has worked so nicely.
diodes / resisters / inductors ... guess I have some more things to read up on. Any links?
[/ QUOTE ]
__________________
The idea behind the diodes comes from an EE that I asked to design something for me in the past that pulled from two battery packs - sort of like your setup. He agreed to do it under one condition - had to have reverse protection diodes to keep from sending one pack into reverse.
His logic is that batteries are never exactly alike, either in starting voltage, or voltage during use, so one pack might end up being a higher voltage than the other, causing reversal. He must have had a bad experience with it because it was his only "must have" in the whole project.
I am more used to LED light setups, where you burn off the slight excess voltage with a resistor or use a buck converter. I am just not used to seeing a mixed pack - prob ok - certainly interesting.
Re: Litho\'s pics: Double Stack
Is it more safe to store the double stack outside of the host when you're not using it? Or does it make a difference? I tried it for the first time tonight. Unbelievable. It absolutely blows away my 2C 3X123 mods...and they're pretty bright. This was amazing. I had a bunch of people tell me they wanted to buy one until I told them that the battery situation is a little more complicated than they think. One guy thought there would be a great market for a light like that....until he found out it would probably cost a good $100 to put together, then dealing with battery issues...but it sure is fun.
Is it more safe to store the double stack outside of the host when you're not using it? Or does it make a difference? I tried it for the first time tonight. Unbelievable. It absolutely blows away my 2C 3X123 mods...and they're pretty bright. This was amazing. I had a bunch of people tell me they wanted to buy one until I told them that the battery situation is a little more complicated than they think. One guy thought there would be a great market for a light like that....until he found out it would probably cost a good $100 to put together, then dealing with battery issues...but it sure is fun.
