2C Mag mod-need hassle-free 4.8V solution.

14 posts / 0 new
Last post
dorpmuller
dorpmuller's picture
Offline
Last seen: 1 month 5 days ago
Joined: 10/20/2010 - 18:29
Posts: 816
Location: Central Pa., U.S.A.
2C Mag mod-need hassle-free 4.8V solution.

Title says it all... I can fit an IMR 26650 in after I've stripped off the wrap. Glued the insulating ring back on the + end so no shorting risk. Works fine with no hack-job sanding or filing.

However, to get max performance I need to bump it up to 4.8V. Any ideas?

Please don't mention boring or machining-no access or money to do so. Same with unaffordable/unavailable/vaporware tailcaps. Some were promised to me and never materialized. This must be a simple, no-machining process.

I do know about the small sub-C's that Battery Junction sells-I have four in a 2D that I did-but would require unobtainium parts for a 2C.

Thanks,

Rich

"I am the flashlight king! I can light anything!"

Ford Prefect
Ford Prefect's picture
Offline
Last seen: 1 week 4 days ago
Joined: 06/13/2011 - 08:07
Posts: 847
Location: Canada, eh!
Is 4.8v a min max or optimum and what is the max voltage that is ok?
dorpmuller
dorpmuller's picture
Offline
Last seen: 1 month 5 days ago
Joined: 10/20/2010 - 18:29
Posts: 816
Location: Central Pa., U.S.A.

That's the absolute max... can't go any higher. It has 7135 drivers and I don't want to go to 6V-too much heat would get generated by the 7135's.

"I am the flashlight king! I can light anything!"

Confusius
Confusius's picture
Offline
Last seen: 2 months 5 days ago
Joined: 04/23/2011 - 20:12
Posts: 265
Location: Germany

Tough one! Well, there are 1/2 C-NiCd-cells out there, so you could theoretically put four of them in your 2C  Mag... but they only have 650 mAh, so that is probably not enough for your needs. Seem to be quite rare, too. Could only find these here:

http://www.pollin.de/shop/dt/MTExOTI3OTk-/Stromversorgung/Akkus/NiCd_Akk...

Not a lot of help, I'm affraid

Confusius Say

Take out the fortune before you eat the cookie.

shhh
shhh's picture
Offline
Last seen: 1 week 1 day ago
Joined: 09/10/2011 - 07:53
Posts: 211
Location: Winnsboro,Texas

dorpmuller wrote:


unobtainium parts for a 2C.


What is so unobtainium?

dorpmuller
dorpmuller's picture
Offline
Last seen: 1 month 5 days ago
Joined: 10/20/2010 - 18:29
Posts: 816
Location: Central Pa., U.S.A.

shhh wrote:

dorpmuller wrote:


unobtainium parts for a 2C.


What is so unobtainium?

Custom C tailcaps of any kind. Either too much money, or wound up vaporware/promiseware. Had some promised by someone for months and never materialized nor do I expect them to by now. And I'm not gonna spend more on CPF for one that costs more than the whole light, batteries, everything.

Rich

"I am the flashlight king! I can light anything!"

mitro
Offline
Last seen: 2 months 4 days ago
Joined: 01/25/2011 - 11:58
Posts: 707
Location: Montgomery, IL USA

About the closest would be a LiFePO4 26650 and a 4/5 Sub C NiMH and that's not ideal. You'd want ones with capacities that were very close (if possible) and watch carefully how much you discharge it.

 

EDIT: On second thought, you could use a 26650 and a 4/3A NiMH (18650 size) and de-annodize the inside of tailcap and run springless. You could even try your LiMn 26650 if you aren't afraid of a little extra voltage.

ttwhin
Offline
Last seen: 7 years 9 months ago
Joined: 11/01/2011 - 14:19
Posts: 6

Hi i am new here.

"edit" i was reading 8,4 and it was written 4,8. My bad, i gave useless advise

Don
Don's picture
Offline
Last seen: 2 years 7 months ago
Joined: 01/12/2010 - 16:32
Posts: 6617
Location: Scotland

C cells are nominally 26.2x50mm so you want 100mm length for four NiMH - which will be nearer 6V fully charged, might want them to rest a bit before use.

Mag springs are usually silly strong and long - if you clean out the tailcap you probably can get another 15-20mm to play with - lets say we have 120mm possibly so 4 cells of 30mm or less.

 

Sub-Cs are normally 22.2 by 42.9mm so you'll only get there of them in. Two B cells would fit - but that wouldn't be adequate voltage. 2/3A cells should do the trick but they are only 16.5mm in diameter. You'll easily get four of them in a 2C though as they are only 26.5mm long. These should be easily available.

 

There is a 2/3 sub-C which is 26.5mm long and 22.8mm in diameter with a capacity of 1500mAh. The place I use is in the UK so wouldn't be a lot of use to you.

http://www.component-shop.co.uk/html/single_cells.html

But it has a list of the commoner sizes that are easily available.

 

There are a lot of other sizes too.

 

This may be of some use

http://www.batteryspace.com/ni-mhbatteries.aspx

http://www.batteryjunction.com/

 

Hopefully this isn't teaching granny to suck eggs.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

dorpmuller
dorpmuller's picture
Offline
Last seen: 1 month 5 days ago
Joined: 10/20/2010 - 18:29
Posts: 816
Location: Central Pa., U.S.A.

mitro wrote:

About the closest would be a LiFePO4 26650 and a 4/5 Sub C NiMH and that's not ideal. You'd want ones with capacities that were very close (if possible) and watch carefully how much you discharge it.

 

EDIT: On second thought, you could use a 26650 and a 4/3A NiMH (18650 size) and de-annodize the inside of tailcap and run springless. You could even try your LiMn 26650 if you aren't afraid of a little extra voltage.

Thought of that but sounds scary, as in Boom!!

I did exactly that with a 3C though-ground out the tailcap so I could get 4 sub-C's in the light. What a bitch-I don't have a Dremel, either!

Rich

"I am the flashlight king! I can light anything!"

Essexman
Offline
Last seen: 3 days 10 hours ago
Joined: 01/30/2011 - 18:18
Posts: 681
Location: UK

Would 3  C NiMH not work with 7135 drivers ?

 

Edit - I guess you are going to run more than one LED = high current draw?

dorpmuller
dorpmuller's picture
Offline
Last seen: 1 month 5 days ago
Joined: 10/20/2010 - 18:29
Posts: 816
Location: Central Pa., U.S.A.

Essexman wrote:

Would 3  C NiMH not work with 7135 drivers ?

 

Edit - I guess you are going to run more than one LED = high current draw?

10 amps.

"I am the flashlight king! I can light anything!"

Ford Prefect
Ford Prefect's picture
Offline
Last seen: 1 week 4 days ago
Joined: 06/13/2011 - 08:07
Posts: 847
Location: Canada, eh!

SST90?

Essexman
Offline
Last seen: 3 days 10 hours ago
Joined: 01/30/2011 - 18:18
Posts: 681
Location: UK

Ah yes, thinking better now I've had some sleep. It's all dependent on the Vf of the LED being used too.

This thread has made me see something else. You can fit three sub C cells into the space of 2 *26650 cells.