4AA to D adapter Thread

Edit - Nov 29, 2004. I have been PM contacting others in the CPF who have needed and worked on adapters. One of them is fivemega, who is well ahead of my thinking and program for AA to D style adapters.

I have requested that he post some information about his AA to D adapter program in this post, and link it to a new thread he will likely start in the next 2 weeks. While his offering in this area is still slightly different than what I had in mind, he is very focused on the M-G style, D cell size lights, while I am not at all focusing on them.
This puts him in a much better position to support your adapter needs than I would be, at least in the next few months.

My plans are for more LED ground up designs, one which will be a 100 gram model Lux III, hopefully introduced this month, ready for shipment. With this and other LED related projects I have going, my latest estimate has been that it would take me several months to complete this, while fivemega will have an offering in December.

If for some reason your needs are not met with his offering, and he cannot help you, I will consider to look at this again on a custom build basis. In the meantime, please welcome fivemega's upcoming posts and thread connection with my blessing.

Edit Nov 27, 2004 - There seems to be two schools of thought out there on this adapter - a few have signed up to obtain this adapter with the thought that $ 30 is high but ok for the feature set.

A few have commented that they will buy if I do the work and give them some money along with the adapter, or prefer bailing wire approaches - which is not really my approach to life (not that I have not done this, I just haven't sold that sort of thing.

For what it will cost to build these, and the related design challenges, I am thinking that it would be just as easy and cost effective to just build a custom battery tube that replaces the existing tubes on a m@g or similar light.

These could be built 1, 2, 3, or 4 cells long, and fit any of the AA cells. For that matter, I could make one for 123 cells. Series and parallel versions could be made, and an adapter on the end could be made to screw on the desired light.

Price would be < $ 100 / each. Any comments ?

_______________________________

I have been watching various interests in AA to D converters, and some of the challenges from the past attempts. Chief Wigwam made some great ones, which by his own admission were a PITA to make. They were so popular, that they are like precious jewels to obtain. I have decided to make an attempt as well since there seems to be a need by the community.

I am committing to work on this project, but not necessarily success or a timeline. We all know how this goes, and I tend to be a bit – detailed. I will keep the top post updated with questions and answers as they come up, and will request that anyone that is interested or curious please add to the knowledge base, as correcting mistakes takes time and money.

Please use this post for your communications on this project unless it REALLY needs to be private. I would like to focus on the project and not on answering PMs (I am not a fast typist)

When it comes to the final assembly, I might need some extra hands to help pull this off. When the time comes, I will post a sign up sheet if needed.

4AA to D – Series Version – FAQ / Info


Common Use
- This adapter would be used in situations where the flashlight body would normally use a D size cell, but the user needs a higher voltage.

Voltage
- 4 x 1.5 volts to produce nominal 6.0 volts using alkaline or Li based AA
- 4 x 1.2 volts to produce nominal 4.9 volts using NiCad or NiMH based cells
- 4 x 3 volts to produce nominal 12 volts using specialty 3 V Li AAs.

Current
- The current available from an individual cell will determine the available current in the adapter. This adapter will not increase the available current, as it contains no electronics for voltage to current conversion.
- There is a request for 8 - 10 amps for this version. The current limit will ultimately be determined by the diodes. The diode I had planned on using is a 1206 surface mounts size, and has a capacity of 1 amp per diode. 10 amps - have to think about this need and the limited space available.
- I will set 8 - 10 amps as the design target per the requests below.
- Thanks for the explanation of the need - it helps.

Charging the cells
- It will be necessary to remove the individual cells to charge them. This is a safety feature and all adapters will include it.

Design and Materials of Construction
- I have a basic idea for the build, but I want to do a layout before posting it up.
- For an application for 10 ams, and a loss in the diodes of 0.3 volts, there is already 3 watts of heat to dissipate per pack.
- I will most likely make the adapters from machined, anodized Al.

Protection
- The adapter will contain diodes to prevent reverse current flow at one location in the adapter. This will prevent the "pack as a whole" from reverse current flow.
- The protection diodes will reduce the voltage approximately 0.3 volts per adapter. In other words, the diodes would be put in to the pack in one location to prevent "overall" reverse current protection, not at each cell connection.
- An example where the diode would be useful
- User accidentally loads one Li AA in reverse, and the rest properly. The cell will go into reversal and potentially an accident.
- Anyone who wishes to further mod the pack of course can, but I live in CA, the liability capital of the world (ok, after NY)

AA Sizes
- The intention is to use IEC standard cell diameters and lengths.
- If someone has a AA cell which is larger in diameter, please post.
- The AA IEC dimensions are

Price
- I am just getting this started, so I do not have a final price
- I am targeting to make 100 of each type to achieve some economy of scale
- The goal is to keep these under $ 30 per adapter. When you sign up below, please assume a $ 30 per adapter price, and a realistic need number based on this. I cannot really do a build for the group if people are signing up for a "range" of need that spans a factor of 10.
- For those concerned about the price, I am doing this build mostly for others as a community offering, not really even for my own use. The "5" next to HarryN was just to make a starting point list. I am mostly working with Lux III LEDs, small lights, and 123 or 223 batteries.
- My occasional needs for "D sized power" can be met quite well with SAFT Li D cells.
- I recently had some (100 ea) heads made for a custom 223 light I am building for Xmas presents. I had bids from several shops in different parts of the country - I think $30 is going to be real close. In order to support 8-10 amps, it will take almost $ 4 just in diodes.

If there is something out there which suits the needs of everyone for $20, please post it the thread, and we can just all buy what we need without all of my time and effort. I will be tying up $ 30 x 100 parts = $ 3,000 of my money, so don't feel like you have to spare my feelings seeking out an alternative.

4AA to D – Parallel Version – FAQ / Info

Common Use
- This adapter would be used in situations where the flashlight body would normally use a D size cell, but the user needs a current flow, or prefers to use AA cells.

Voltage
- The voltage will be the same as the nominal cell voltage, minus the reduction due to the cell reverse protection diodes.

Current
- The current available from the cells will be nominally 4 x the current available from an individual cell.
- The adapter and protection diodes will be sized for approximately 1 amp per cell.

Charging the cells
- It will be necessary to remove the individual cells to charge them. This is a safety feature and all adapters will include it.

Protection
- The adapter will contain a diode for each cell to prevent reverse current flow.
- There is no protection against over discharge of the cell.

AA Sizes
- The intention is to use IEC standard cell diameters and lengths.
- The AA IEC dimensions are


Price
- I am just getting this started, so I do not have a final price
- I am targeting to make 100 of each type to achieve some economy of scale
- The goal is to keep these under $ 30 per adapter.

4AA to D – Series / Parallel Version FAQ / Info

Common Use
- This adapter would be used in situations where the flashlight body would normally use a D size cell, but the user needs a combination of more current flow and a higher voltage, or prefers to use AA cells.

Voltage
- Two pairs of cells in series (2 x 2 configuration)
- For a nominal 1.5-volt cell, the voltage would be 2 x 1.5 = 3 volts from the cells, then a loss of approx. 0.3 volts for the protection diode.

Current
- The current available from the cells will be nominally 2 x the current available from an individual cell.
- The adapter and protection diodes will be sized for approximately 2 amps per cell pair (4 amps total)

Charging the cells
- It will be necessary to remove the individual cells to charge them. This is a safety feature and all adapters will include it.

Protection
- The adapter will contain a diode for each cell pair to prevent reverse current flow.
- There is no protection against over discharge of the cell.

AA Sizes
- The intention is to use IEC standard cell diameters and lengths.
- The AA IEC dimensions are

Price
- I am just getting this started, so I do not have a final price
- I am targeting to make 100 of each type to achieve some economy of scale
- The goal is to keep these under $ 30 per adapter.

4AA to D – Series Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells all in series, putting out a nominal 6 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5

4AA to D – Parallel Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells in parallel, putting out a nominal 1.5 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5

4AA to D – Series / Parallel Version – Sign Up List

This is the sign up for the version with the AA cells in a 2 by Series, 2 by parallel version, putting out nominally 3 volts from 2 each 1.5 volt AA cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.


Name Number
HarryN 5

4AA to D – Series Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells all in series, putting out a nominal 6 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5
icarus 2

HarryN,

I think you should also offer these holders without the protection diode.
I'm prepared to help with the final assembly.

Freddy

[ QUOTE ]
icarus said:
HarryN,

I think you should also offer these holders without the protection diode.
I'm prepared to help with the final assembly.

Freddy

[/ QUOTE ]

Thanks Freddy - I will add a diode comment in the top post. Please feel free to comment / add - more info will help us all.

Thanx for answering mine (and many others) prayers /ubbthreads/images/graemlins/bowdown.gif

4AA to D – Series Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells all in series, putting out a nominal 6 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5
icarus 2
ensig 4

Name Number
HarryN 5
icarus 2
ensig 4
xpitxbullx 4

4AA to D – Series Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells all in series, putting out a nominal 6 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5
icarus 2
ensig 4
bwaites several(dependant of final cost, but may be as many as 50, or as few as 3)

Bill

On the series version at least, 2 Amps won't get it.

I would suggest a minimum of 6-8 amps and preferably 10 Amps, (at least momentarily), with steady state of at least 6.

Bill

[ QUOTE ]
bwaites said:
On the series version at least, 2 Amps won't get it.

I would suggest a minimum of 6-8 amps and preferably 10 Amps, (at least momentarily), with steady state of at least 6.

Bill

[/ QUOTE ]

I will post an edit in the top post.

4AA to D – Series Version – Sign Up List

This is the sign up for the version with the AA cells, all 4 cells all in series, putting out a nominal 6 volts from 4 each 1.5 cells. Please do not post questions in this section of the post – put them in the FAQ section and I will add the answers to the top of the post when I can.

Please copy the entire sign up post with the names and add yours to the bottom if you are seriously interested, although, you are not monetarily committed of course.

Name Number
HarryN 5
icarus 2
ensig 4
bwaites several(dependant of final cost, but may be as many as 50, or as few as 3)
thesurefire (up to 2 depending on specs and price)

[ QUOTE ]
HarryN said:
[ QUOTE ]
icarus said:
HarryN,

I think you should also offer these holders without the protection diode.
I'm prepared to help with the final assembly.

Freddy

[/ QUOTE ]

Thanks Freddy - I will add a diode comment in the top post. Please feel free to comment / add - more info will help us all.

[/ QUOTE ]

That's the initial FAQ/Info post for series version, not initial "top" post of this thread.

I'll provide link from the other forum as you have incorrectly stated this one to be in 'Custom' forum, which is confusing.

On series version, please edit to state 0.3v per diode/cell loss or 0.3v per 4-cell-D adapter. 12 AA in a 3x4 setup would mean 3.6v loss if it were per cell. As it is 0.9v might be acceptable to some, not to others. The edit on diodes issue only states you can modify as you wish, but would it be easy to remove the diodes and then solder direct wire connection?

$30 per adapter would mean $90 for a M*g3D, which is rather pricey. 8AA-2D Willie Hunt/Skip Langan adapter was only $20.

Can you post a detailed description on materials/construction specifics, and better yet an illustration (or get someone else to do this)? As you say, it is expensive to change design, so getting it refined early on is desirable.

To clarify, the current diode planned is 1amp per cell, for 4a total through adapter(assuming little resistance losses)? Then 2a per cell diode would mean 8a total current flow through the adapter, correct?

bwaites is of the "Mule" fame, as such he and Ginseng and other high-power freaks like to use 12v or 24v Osram projector bulbs in their mods, of 100 to 250watts, therefore the need for lots of current capability.

Any possibility of an 8AA-2D adapter along with the 4AA-D? This provides 2, 3(4AA-D + 8AA-2D), 4 (2x 8AA-2D) and so on, up to the M*g6D S4MadMan was using for the 'Mini-Aurora'

HarryN,

Many of the SUPERBULBS available from Carley and WelchAllyn, as well as Osram, require 3-4 amp draws.

The higher powered 12 volt and up bulbs require 6-8 amps draws, thus the request, as noted by UDAMAN above.

Bill

yes i agree that 30 for one of these is way too much. Also 8aa - 2D are already being sold on this forum. Also I its true that these are a real PITA to make. I tried to make a 6AA - 2D holder for my Maglight and that thing is just hard to make reliable. The current design for the 8aa - 2d leaves little to be improved on also because that is the only possible way to make a battery holder fit all those batteries and still fit in the mag tube. Also high capacity Ni-Mh batteries will not fit in a configuration of 4, in a mag tube.