Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

cr2 battery question

herektir

New member
Joined
Feb 26, 2010
Messages
31
Likes
1
Points
0
Hi. I'm fairly new to the forum and have a question. I have used the search function but cant find the answer with the many many pages of topics that dont actually address the problem.

I have just ordered a 50 mw bluray waterproof laser from rayfoss based on general opinions on this forum about various companies. The problem is that it comes with a 3v cr2 battery and i was wondering what li ion rechargable is of the same size and is 3.7v . I think with red lasers I would have to use a bucking circuit to decrease the voltage but with violet lasers running at around 5v depending on the driver it should be fine.

I've also browsed around enough to realize that IgorT is one of the respected builders here and ordered a laser from him of higher power at the end of last month and I'm really anticipating its completion and delivery.



Optotronics 100mw 532nm
Optotronics 5mw 532nm
laserylyte 5mw 650nm
old cheap 670nm
 

herektir

New member
Joined
Feb 26, 2010
Messages
31
Likes
1
Points
0
I've been to numerous sites that sell batteries and most are just 3v nonrechargable and some rechargables. After more digging i finally found the 3.7 volt rechargables( 15266) but they are unprotected and ive not been able to find any protected on sale online. I tend to avoid ebay due to sometimes dubious sellers.

Does anyone know of a company that sells protected cr2 3.7v rechargables or are they too small for the protection crkt?
 

Morgan

New member
Joined
Feb 5, 2009
Messages
2,178
Likes
127
Points
0
Hi herektir,

You might find what you're looking for here: RCR2 Unprotected Rechargeable Lithium Battery

[edit] actually just had a trawl and came up empty myself. Not much help in the end. If I come across anything interesting I'll repost. Sorry.

There was another place called, 'Battery Junction', too.

These links were found in some of Jayrob's kit threads.

I hope that's helpful.

M
:)
 
Last edited:
Joined
Jan 20, 2009
Messages
3,635
Likes
91
Points
0
Keep in mind that 3V non-rechargeable CR2 are 3.2V, but, there are 2 types of rechargeable ones:

marked as 3V that charge to 3.6V
marked as 3.6/3.7V that charge to 4.2V

I guess the driver will handle the first ones, but I wouldn't use the second ones.
 

herektir

New member
Joined
Feb 26, 2010
Messages
31
Likes
1
Points
0
Thankyou for the responses. Ive ordered 2 rechargables but they are unfortunatly unprotected. I can find nothing about protected rcr2.

I came across a post on candlepower forums about using unprotected batteries and testingthe voltage under no load after set time periods of use to try to judge when to safely not over discharge them. I cant find the post right now but under no load the values ranged something like
%charge v across battery(0 load)
100% 4.2v
80% 4.1v
60% 4v
40% 3.9v
20% 3.8v
0% 3.7v

Those value are the best i can remember. Does this sound right to any battery experts out there?
 

billg519

New member
Joined
Feb 21, 2008
Messages
1,056
Likes
84
Points
0
I have both kinds of these batteries. Neither type of mine is protected. The 3.0V type is at 3.6V when fully charged, and 2.0V discharged. This battery should be charged before it falls to 2.0V. Maybe charge it when it reads 2.2 to 2.4V to be sure. The other type I have is the 3.6V, which is at 4.2V when fully charged and 2.8V when discharged. Maybe charge this one when it reads around 3V.
 
Joined
Oct 7, 2009
Messages
1,054
Likes
44
Points
0
Keep in mind that 3V non-rechargeable CR2 are 3.2V, but, there are 2 types of rechargeable ones:

marked as 3V that charge to 3.6V
marked as 3.6/3.7V that charge to 4.2V

I guess the driver will handle the first ones, but I wouldn't use the second ones.
I ordered a rechargeable CR2 from HTD for my aquarius, It tested at 3.3v, anything above that i wouldnt use, im to paranoid about frying a $450 laser
 
Joined
Aug 28, 2009
Messages
1,071
Likes
59
Points
0
Last edited:

Morgan

New member
Joined
Feb 5, 2009
Messages
2,178
Likes
127
Points
0
Joined
Aug 28, 2009
Messages
1,071
Likes
59
Points
0
Hey Greenmechanic,

I fell into this trap too in an earlier post. The OP was looking for 3.7V protected not the 3V ones. Didn't take me long to find the 3V ones but 3.7V protected? No news so far...

M
:)
Thanks for pointing this out. I guess I read the post to quickly. I'll keep looking, but not much hope now.:undecided:
 

herektir

New member
Joined
Feb 26, 2010
Messages
31
Likes
1
Points
0
I ordered 3.7v li ion rcr2 but due to a screwup they sent 3.0v. I talked to the company and the sent 2 more and they are 3.7v.

My question is this. One of the 3.0v reads 3.45v no load which seems correct but the other is 3.89v which seems very high. The 3.7v batteries no load read at 3.81v and 3.75v Is it possible for a 3.7v to be mislabed as a 3v and if so is it very common?
 




Top